US3757375A

US3757375A - Obstruction removal apparatus

Info

Publication number: US3757375A
Application number: US00172749A
Authority: US
Inventors: M Strom
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-08-18
Filing date: 1971-08-18
Publication date: 1973-09-11
Anticipated expiration: 1990-09-11

Abstract

A device for extracting obstructions from confined spaces includes a flexible outer shaft movable relative to an inner central member. The central member is attached to the outer shaft and in a first embodiment, contains one or more teeth or claws. Upon insertion of the device into an obstructed space, the claws are retracted inside the shaft for easy passage past the obstruction. During withdrawal of the device from the space, the claws become extended beyond the outer shaft, thereby facilitating positive engagement of the obstruction. In an alternative embodiment, the claws are replaced by one or more sections of the outer shaft having longitudinal slits or striations. During insertion of the device, the slitted sections are expanded longitudinally, narrowing these sections for easy passage into the pipe. During withdrawal, the sections are longitudinally compressed, resulting in their radial expansion or bellowing, and enabling engagement of the obstruction.

Description

United States Patent 1 Strom 1 1 OBSTRUCTION REMOVAL APPARATUS Martin Strom, 261-01 69th Ave., Floral Park, L.l., N.Y.

[22] Filed: Aug. 18, 1971 1211 Appl. N0.: 172,749

[76] Inventor:

Primary ExaminerEdward L. Roberts Attorney-Barry H. Freedman ABSTRACT A device for extracting obstructions from confined spaces includes a flexible outer shaft movable relative to an inner central member. The central member is attached to the outer shaft and in a first embodiment, contains one or more teeth or claws. Upon insertion of the device into an obstructed space, the claws are retracted inside the shaft for'easy passage past the obstruction. During withdrawal of the device from the space, the claws become extended beyond the outer shaft, thereby facilitating positive engagement of the obstruction. In an alternative embodiment, the claws are replaced by one or more sections of the outer shaft having longitudinal slits or striations. During insertion of the device, the slitted sections are expanded longitudinally, narrowing these sections for easy passage into the pipe. During withdrawal, the sections are longitudinally compressed, resulting in their radial expansion or bellowing, and enabling engagement of the obstruction.

34 Claims, 10 Drawing Figures PAIENIEDSEPI 1 m8 SHEEI 1 [IF 2 lNl/E/VTOR MART/N STROM PNENTED SEPI I I975 SHEET 2 [IF 2 u I Wm J m w 8 S a 1 OBSTRUCTION REMOVAL APPARATUS BACKGROUND OF THE INVENTION Sewer snakes and other devices heretofore known in' the prior art for removing obstructions from confined spaces have usually comprised flexible shafts formed of a spiral wire having affixed at their leading ends a hook, claw, or other attachment intended to impale or dislodge the obstruction. The successful operation of such devices has been limited, however, because the teeth or claws themselves impede insertion of the device into pipes or other confined spaces having bends or turns therein. These devices have also posed problems because of their random or non-positive action in engaging obstructions of unknown shapes and substances. In many cases, the use of prior art devices has resultedin merely pushing the foreign object further down the pipe or duct, where it becomes lodged more firmly and still more difficult to remove. Oftentimes, disassembly of an obstructed portion of a pipe may then be necessitated, with the attendant consumption of a good deal of time and effort. Where the obstruction is located within a body duct or vessel, surgery may then be required.

To attempt to overcome these difficulties, other prior art devices have employed retractable grappling members which are held within a flexible shaft during its insertion into a pipe or other confined space, thereby reducing the tendency of the claws or teeth'to resist insertion of the device. In such prior art devices, however, the grappling member is typically actuated by the application of a pushing force on a wire which holds the grappling member in place. Where the obstruction is firmly lodged within the pipe, such a manipulation may be insufficient to actuate the claws, sincerthe pushing force exerted on the inner wire is not easily transmitted to the grappling member. In this event, the wire may merely become deformed and of no'further use. In addition, the configuration of such devices precludes the attachment of cutting tools to the leading end of the apparatus, where the retractablegrappling member is situated. Also, the types of handles or extension devices that may beattached to the trailing end of the apparatus is restricted, since provision must always be made for the grappling member control wire.

In view of the aforementioned difficulties associated with prior art snake-like devices, it is the broad object of the present invention to provide an improved device that is uncomplicated and inexpensive to construct, simple to operate, and likely to positively engage and remove foreign objects from confined spaces.

A further object of the invention is the provision of such a device capable of fabrication from a variety of materials and in numerous lengths and sizes,'enabling its use in such diverse fields as plumbing and surgery, and in any other field wherein foreign objects must be positively engaged and removed from confined spaces of various kinds.

Yet another object of the invention is the provision of an obstruction extraction device capable of carrying a variety of cutting tools at its distal end, and a handle or extension device at its proximal end, in addition to, and without impeding the operation of, a plurality of claw-like protrusions designed to positively engage the obstruction by their extension from the body of the device.

An additional object of the invention is the provision of a device for generally cleaning the interior portions of elongated tubes or ducts that advantageously utilizes friction forces generated between the outer shaft of the device and the interior duct surfaces to longitudinally displace the outer shaft with respect to an inner central member attached to the outer shaft, so that one or more claws responsive to the longitudinal displacement are radially retracted during insertion of the device and radially extended during withdrawal of the device from the duct.

SUMMARY OF THE INVENTION The present invention avoids the previously mentioned difficulties of prior art snake-like devices, and meets the above stated and other objects, by the provision of an obstruction extraction apparatus wherein one or more claws or teeth designed to remove obstructions from and generally clean the interior of a pipe, duct, or other confined space, are automatically retracted toward or into, or extended from, the body of the device by friction forces exerted on the device during its insertion and withdrawal, respectively, from a confined area.

More specifically, there is provided in a first embodiment of the invention a tool or device of the type described which includes a flexible outer shaft of coiled wire or other suitable material, and an inner central member of solid or stranded wire or the like, fastened to oneor both ends of the outer coil. The outer shaft is comprised of a tightly coiled, relatively long center section, and one or two loosely coiled, relatively short other confined space produces friction forces between the outer shaft and the inner walls of the pipe, tending to rearwardly displace the outer shaft relative to the in'ner central member. As a result of the relative'motion, the teeth or claws attached to the inner central member are retracted into or covered by the outer shaft. Accordingly, insertion of the device can proceed, unimpeded by the resistance of the claws. Upon withdrawal of the device from the pipe, friction forces are reversed, as is the direction of relative motion between the inner central member and the outer shaft. The teeth or claws attached to the inner central member are extended from the outer shaft, and are in a suitable position to easily engage and remove an obstruction lodged within the pipe.

In an alternative embodiment, the previously mentioned claws are replaced by one or more sections of a hollow tubular outer shaft having longitudinal slits or striations that enable longitudinal compression'of the sections. During insertion of the device, the previously mentioned friction forces acting between the outer shaft and the inner walls of the duct being cleaned serve to elongate and therefore constrict the slitted section, permitting easy passage of the device past an obstruction. During withdrawal, when friction forces are reversed, the slitted sections are longitudinally compressed, resulting in their radial expansion or bellowing. The portion of the slitted sections of the outer shaft that are thus radially extended act in much the same manner as the aforementioned claws in enabling positive engagement and removal of the foreign article.

As is apparent from the preceeding description, the above stated and other problems of prior art devices of the type described are obviated, and the stated and other objects are attained, by the provision of a device in accordance with the principles of the instant invention. Positive engagement of an obstructing article is enabled by the automatic extension of teeth or claws from the body of the device during its withdrawal from a pipe or duct. Impediment to the insertion of the device is minimized by the retraction of the teeth or claws during insertion of the device into a pipe or other confined space.-In addition, since the teeth are extended from the body of the device, its leading end may be adapted to carry a variety of cutting or cleaning implements that may further serve to facilitate its operation, while the trailing end may similarly be arranged to permit engagement with a handle or an extender apparatus. Also, it is'to be observed that a pulling rather than a pushing force is utilized to extend the teeth or claws into engaging position, thereby eliminating a source of difficulty in prior art devices.

BRIEF DESCRIPTION OF THE DRAWING The above stated and other aspects and features of the invention may be more easily understood and appreciated from a consideration of the following detailed description when read in light of the accompanying drawing, in which:

FIG. 1 is a partially cut-away view, in elevation, of a first embodiment of a device in accordance with the principles of the invention, shown in its static condition;

FIG. 2 is an enlarged view, in elevation, of the leading portion of the device of FIG. 1, during its insertion into a pipe or other'confined space;

FIG. 3 is a view similar to FIG. 2, showing the leading portion of the device during its withdrawal from a pipe or other confined space;

FIG. 4 is a view in elevation illustrating a cleaning device constructed in accordance with the principles of the invention in position for removing an obstruction from a curved pipe section, diagrammatically indicated by broken lines;

FIG. 5 is a partially cut-away view, in elevation, of an alternate embodiment of a device in accordance with the principles of the invention, shown in its static condition;

FIG. 6 is a view, in elevation, of the device of FIG. 5 during its insertion into a pipe or other confined space;

FIG. 7 is a view similar to FIG. 6 showing the device during its withdrawal from a pipe or other confined space;

FIG. 8A is an edge view of one portion of the device of FIG. 5, in its static condition; and

FIGS. 88 and 8C are edge views similar to FIG. 8A of the same portion of the device during withdrawal and insertion, respectively.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, there is shown one embodiment of an obstruction removing device in accordance with the principles of the invention, comprising a hollow outer shaft designated generally as 10, an inner central member or rod 11, and one or more teeth or claws, such as claws 12 and 12'.

Outer shaft 10, which may be fabricated from a single helically coiled strand of metal or plastic wire or any other material possessing suitable characteristics of strength and flexibility, includes three sections, 10a, 10b, and 106. Section 10a, which is relatively long in comparison to the remaining sections, is arranged so that adjacent coils are in close proximity to each other, and is generally located at the center of outer shaft 10. Sections 10b and 10c, which are relatively short in comparison to center section 10a, are located toward each end of outer shaft 10, and arranged so that adjacent convolutions are spaced apart with respect to one another, thereby permitting compression of these sections upon application of a longitudinally directed force. Additional closely wound sections 10d, 1014, may be located outwardly from either or from both loosely wound sections 10b,-10c, but are not required in order to obtain satisfactory results in practising the invention. The outer circumference of outer shaft 10 is arranged to be smaller than the inner circumference of the pipe to be cleaned, thereby permitting insertion of the device into the pipe.

Inner central member 11, which may be fabricated from a single or multi-stranded wire of metal, plastic, or other suitable material, is arranged to have a length at least substantially equal to that of outer shaft 10, when the latter is in its static condition, and an outer diameter smaller than the inner diameter of outer shaft 10. Inner central member 11 may be straight, as shown in FIG. 1, or may be helically coiled, if desired.

Outer shaft 10 is fitted around inner central member 11, during assembly, and fastened to each end thereof. Fastening may be accomplished by means of annular washers 13, 14, having an outer diameter substantially equal to that of outer shaft 10 and an annulus permitting extension'of a small length of inner central member 11 therethrough. The washers may be attached to the endmost coils of outer shaft 10 by welding or other means, and the extension of central member 11 may be attached to the annular washers 13, 14, also by welding. Of course, other methods of-fastening may readily be devised by those skilled in the an; and are intended to be within the scope of the invention.

Either or both washers l3, 14 may be formed as part of, or have attached thereto, fittings 15, 16, respectively, which may be provided with externally or inter coil shaped leading extremity that may on occasion be useful in ensnaring certain obstructions. A handle may be attached to fitting 15, thus providing a comfortable means of gripping the device, or the entire device of FIG. 1 may be attached to the front end of a conventional coiled snake, thereby extending the range of the apparatus to include confined spaces far removed from an initial point of entry.

Fastened to inner central member 11 are one or more claws I2 and 12, which may be fabricated from a sin gle or stranded plastic or metal wire, or from any other material suitable for the purpose. As shown in FIGS. 1 and 3, the claws are preferably attached to inner central member 11 at a point forward of, or toward the front of, section c of outer shaft 10, although it may be advantageous especially in the case where inner central member 11 consists of a stranded wire, to simply double back all or some of the strands from the attachment point at washer l4. Claws i2 and 12' are arranged to extend outwardly from inner central member 11 at a generally acute angle to the rear portion of the device, the free ends or tips of the claws protruding from outer shaft 10 at a point toward the rearmost end of section 10c. The length of claws l2 and 12 is selected such that, in the static condition of the device, the displacement D between their free ends and outer shaft 10 is maintained relatively small in comparison to the diameter of outer shaft 10. Where more than a single claw or tooth is employed, they are preferably arranged to be spaced substantially equally around the circumference of outer shaft 10. The tips or extremities of claws l2 and 12 may be curved outwardly from shaft 10, as shown'in FIG. 1, or may be inwardly curved as is tooth 12a shown in FIG. 3. Straight, knobbed, or barb-tipped teeth may also be employed, depending upon the circumstances involved, the latter also being illustrated by claw 12b of FIG. 3.

Operation of the device of FIG. 1 may best be appreciated with reference to FIG. 4, which illustrates diagrammatically an S shaped pipe section 40, quite common in the plumbing field and typical of pipe sections of other shapes, into which the device may be inserted in order to remove an obstruction.

As shown in FIG. 4, section 10a of outer shaft 10 makes contact with the interior walls of pipe section 40 at several points, such as points 41 and 42, due to the tendency of the device to maintain its naturally straight condition, rather than conform to the curvature of the pipe. When the device is put in motion, friction forces F, and F, are generated at contact points 41 and 42, respectively, and act in a direction opposite to the direction of motion. Thus, if outer shaft 10 is moving into pipe section 40, friction forces F, and F, act on the shaft in a rearward direction. Since these friction forces are, however, exerted only on outer shaft 10, and not on inner central member II, because'the latter is not brought in contact with the pipe walls, there results a rearward displacement of outer shaft 10 through the compression of loosely coiled section 10b and the expansion of loosely coiled section 10c. Stated differently, friction forces acting only on the outer shaft cause a point P on inner central member 11 to be displaced further, in the direction of motion, than a corresponding point Q on outer shaft 10, as can be seen by comparing the positions of those reference points in FIGS. 1 and 2, the latter of which depicts the condition of section 10c of outer shaft 10 during insertion of the device.

Since claws l2 and 12 are attached to inner central member 111, they too are correspondingly displaced longitudinally in relation to outer shaft 10 during insertion. As shown in FIG. 2, the displacement D between the free ends of claws l2 and 12 is reduced or virtually eliminated, since the relative movement between inner member I]. and outer shaft 10 acts to withdraw or retract the claws into outer shaft 10. Easy insertion of the entire device into pipe section 40, and past an obstruction or area to be cleaned, is thereby facilitated, since the resistance offered by the claws is removed.

During withdrawal of the device from pipe section 40, friction forces F, and F are reversed in direction. Accordingly, loosely coiled section is compressed, and loosely coiled section 10b is expanded, or, stated another way, reference point P on inner central member 11 is now rearwardly displaced further than corresponding reference point Q on outer shaft 10, as shown in FIG. 3. As a result,

claws

12 and 12 are extended from outer shaft 10, increasing the displacement D between the free ends of claws 12 and 12' and outer shaft 10. The claws are now in an advantageous position to positively engage a foreign object lodged in the pipe, or to generally clean the interior of the pipe or duct.

Although the device of FIG. 1 is equipped with means for attaching inner central member 11 to both ends of outer shaft 10, it is to be understood that attachment at only a single point, which becomes the functional end of the device, also permits satisfactory operation. For example, washer l3 and fitting 15 may be eliminated, and the proximal end of inner central member 11 extended to form a handle or gripping means for the device, leaving outer shaft 10 attached to inner central'member 11 only at the distal end. In this event, expansion and compression of loosely coiled section 10c occurs as a result of device insertion and withdrawal, respectively, as previously explained, and claws 12 and 12' are thus automatically retracted and extended. Since, in this configuration, the proximal end of outer shaft 10 is free to move with respect to inner central member 1 l, loosely coiled section 10b is not required.

In still another alternate configuration, washer 14 and fitting 16 may be eliminated from the device of FIG. 1, leaving outer shaft 10 attached to inner central member 11 at only the proximal end,without reducing the operational capability of the apparatus. Insertion and retraction of

claws

12 and 12, in; this event, is brought about by the relative movement of outer shaft 10 with respect to inner central member '1 l, as previously explained. Since section 10c of outer shaft 10 is' not attached to inner central member 11 in this configuration, it does not become expanded or compressed during insertion and withdrawal, and is provided only to permit protrusion of the extremities of claws l2 and 12 through the coils of outer shaft 10.

An alternate configuration of adevice embodying the principles of the instant invention is illustrated in FIG. 5, in its static condition. The device includes a hollow tubular outer shaft, designated generally at 50, and an inner central rod-like member 51 positioned inside the outer shaft. Member 51 is shown attached to outer shaft 50 at both ends of the device, via

washers

52 and 53, but as will be explained hereinafter, attachment at only a single end may occasionally be desirable.

Toward each end of outer shaft 50, which may be fabricated from a hollow cylindrical length of plastic tubing possessing suitable characteristics of strength and flexibility, are one or more compressible sections, such as sections generally indicated at 54 and 55, having a length relatively small in comparison to the overall length of outer shaft 50. Each section, such as section 55, is longitudinally slitted or striated, forming a plurality of longitudinal strips of outer shaft 50, such as

strips

56, 57 and 58 which are substantially equally spaced around the circumference of the shaft and define longitudinal apertures or slits, such as

slits

59, 60, and 61 in outer shaft 50. Similar slits, such as slits 69, '70, and 71, and strips, such as

strips

66, 67, and 68, are provided in section 54 of outer shaft 50.

The device of FIG. may be assembled by first precompressing outer shaft 50 by the application at each end of inwardly directed forces. Since

sections

54 and 55 are weakened, to some degree, by the longitudinal slits or striations provided therein, the precompression results in the outward bellowing or radial displacement of

strips

56, 57, and 58, and strips 66, 67, and 68, as

shown in FIG. 1. While still applying a precompression force sufficient to partially compress

sections

54 and 55, inner rod 51 is fastened to both ends of outer shaft 50. As described previously, a handle such as handle 62 or an extender apparatus may be affixed to the proximal end of the device by suitable attachment to washer 52, and various coiled or pointed instruments, such as piercing tool 63 may be mounted on the distal end of the device via attachment to washer 53.

Operation of the device shown in FIG. 5 is essentially similar to that discussed hereinabove in relation to the device of FIG. 1. During insertion into a pipe to be cleaned or unclogged, friction forces between outer shaft 50 and the inner walls of the pipe tend to rearwardly displace outer. shaft 50 with respect to inner central member 51, since the latter is not subjected to the friction forces. The rearward longitudinal movement occasions the compression of section 54 of outer shaft 50 and the simultaneous expansion of section 55 of the outer shaft. As shown in FIG. 6, compression of section 54 beyond its precompressed static condition results in the further outward bellowing or radial extension of

strips

66, 67, and 68, to be discussed in more detail hereinafter. Also depicted in FIG. 6 is section 55 of During withdrawal of the device, friction forces between outer shaft 50 and the inner walls of pipe 90 tend to displace outershaft 50 in the forward direction with respect to inner. rod 51, resulting in the longitudinal compression of section 55 and the longitudinal expansion of section 54 of outer shaft 50. As shown in FIG. 7, compression of section 55 beyond its precompressed static condition results in the outward bellowing or radial expansion of

strips

56, 57, and 58, in the same way that strips 66, 67,and 68 are extended during insertion. The expansion of section 54 results in the constriction or inward radial displacement of

strips

66, 67, and 68, in the same manner that strips 56, 57, and 58 awere inwardly displaced during device insertion.

In order to more fully appreciate the mechanism by which the various strips are radially displaced during compression and expansion of

sections

54 and 55, a single strip 80 typical of each of the

strips

56, 57, and 58, and 66, 67, and 68, is shown in edge view in FIG. 8A in its static precornpressed condition. As can be seen therefrom, a certain displacement H, exists between the apex 81 of the strip and dashed line 85, representing the outer surface of adjacent sections of outer shaft 50. When a longitudinal compression force C and C is applied to each end of strip 80, as shown in FIG. 8B, the outer ends 82 and 83 of the strip are moved toward each other, and, as a consequence, the apex 81 of the strip is radially extended to a displacement H from line 85 which is greater than its previous displacement H When a longitudinal expansion force E, and IE is applied to each end of strip 80, as shown in FIG. 8C, the outer ends 82 and 83 of the strip are moved apart from one another, and, as a consequence, the apex 81 of the strip is radially retracted to a displacement l-I from line 85, which is smaller than its previous displacement H Accordingly, the radial displacement of apex 81 of strip is controlled in response to longitudinal compression or expansion of the strip.

Returning now to FIG. 7, it can be seen that during withdrawal of the device from pipe 90, extended strips 56, 57, and 58 are brought into intimate contact with the interior walls of the pipe, and can therefore advantageously clean these walls. Each apex of

strips

56, 57, and 58 thus acts in a way similar to the claws 12 and 12' of FIGS. 1, 2, and 3 in enabling cleaning of the pipe or engagement of a foreign object lodged within the pipe.

If desired, the device of FIG. 5 may be modified to provide attachment of outer shaft 50 to inner member 51 at only the distal endofthe device. In this event, slitted section 54 is not required, and the device need not be precompressed during assembly. Since the proximal end of outer shaft 50 is free to move relative to inner member 51, it should be apparent that compression of section 55 will occur, as previously described, during device withdrawal from a pipe. During device insertion, slits 56, 57, and 58 will, in this configuration, remain in a fully constricted condition, enabling easy device entry into the pipe.

The preceeding description of the operation of a snakelike device in accordance with the principles of the invention has explained the automatic action of the device in first retracting one or more claws into or toward the body of the device, thereby permitting easy insertion, and then radially extending or outwarnlly dis- I placing the claws from the device duringitswithdrawal from the pipe, thus enabling positive engagement and removal of a clogging object. Since extension and retraction of the claws are both automatic, and result from the advantageous design of the device, it is apparent that the entire device can be attached to the front of a conventional snake-like apparatus, and that the device will operate satisfactorily, and at an extended range. It should also be noted, however, that the device I can be operated manually, in which case an extender cannot be used. In manual operation, using the device of FIG. 1 as an example, the device may be gripped both at its rear or trailing end, and simultaneously at the rearmost end of section 10a of outer shaft 10. By pulling the gripped sections together, loosely coiled section 10b is compressed, and the rearward displacement of section 10a tends to cause the elongation of section 100, thereby retracting or covering claws 12 and 12'. Thus, the device may be inserted into a confined space without impediment from the claws. In the reverse operation, the gripped sections are manually separated or expanded, thereby displacing section 10a in the forward direction. As a result, section 10c becomes compressed, and claws l2 and 12' are thus extended into position for obstruction engagement. Manual operation of the device of FIG. is achieved in an analogous fashion. While manual operation may, on occasion, be desirable when the device is employed in the plumbing field, this mode of operation may be necessary in certain surgical procedures, where sufficient friction resistance to operate the device may not be offered by the interior duct or vessel walls, or where such resistance may be harmful or injurious to the patient. By way of example only, and without limiting-the scope of the instant invention, which is defined by the appended claims, construction of the device of FIG. 1 to the following dimensions and specifications may be found advantageous for use in the plumbing field:

Outer shaft 54; inch steel wire, coiled to 1 inch O.D., overall coiled length 4 feet Section 10a: tightly coiled, length 2 feet, 8 inches Sections 10b and 100: loosely coiled, 14; inch space between convolutions, length 4 inches Sections 10d and We: tightly coiled, length 4 inches Inner central member llz'seven thirty-seconds inch stranded steel wire, four strands at three thirty-seconds inch, length 4 feet, 9 inches Claws l2 and 12': doubled back 9 inches portion of inner central member 11, four claws spaced 90 apart around circumference of outer shaft 10 Washer 13: A; inch steel, 1 inch O.D., A inch l.D.

Washer 14: .4: inch steel, 1 inch O.D., 95 inch I.D.

Many modifications and adaptations-of this invention will readily become apparent to persons skilled in the art. For this reason, it is intended that the invention be limited only by the appended claims. For example, in the preceeding description, outer shaft 10 has been described as fabricated from a single, continuous strand of wire having uniform mechanical characteristics. However, a plurality of wire=segments having the same -or different mechanical properties may be joined together to comprise the length of wire necessary to form the outer coil, without departing from the spirit and.

scope of the invention. More particularly, it may be found advantageous to form outer shaft 10 from a segmented wire, so thatithe spring constants, defined as theratio of force required to produce a given displacement, of end sections 10b and 10c, are lower than the spring constant of center section 10a. By virtue of the selection of such different spring constants, both expansion and compression of sections 10b and 100 require smaller longitudinal forces than does section 10a, and such compression and expansion will occur more readily. As a result, extension and retraction of claws Hand 12 is improved, especially in situationsin which friction forces between the device and the pipe or duct being cleaned are relatively small. It should be apparent that different spring constants for various sections of outer shaft l0 may also be achieved by suitably treating a single continuous strand of wire, either before or after being coiled, as, for example, by removing the temper from selected segments of the wire or coil.

What is claimed is: I

l. A device for cleaning the interior surfaces of an elongated pipe comprising,

a flexible rod for insertion into said pipe,

an outer shaft fitted around said rod, said outer shaft including means for enabling longitudinal movement of said shaft relative to said rod, and at least one claw extending from said device and having a controllable radial displacement from said outer shaft in response to said longitudinal movement.

2. A device in accordance with claim i wherein said outer shaft is attached to said rod at at least one point.

3. A device in accordance with claim 2 wherein said device includes a distal end, and said point of attachment is said distal end of said device.

4. A device in accordance with claim 3 wherein said outer shaft includes a helically coiled wire.

5. A device in accordance with claim 4 wherein said means enabling longitudinal relative movement between said outer shaft and said rod includes at least one loosely coiled section of said outer shaft having convolutions spaced apart one from the other.

6. A device in accordance with claim 5 wherein said at least one claw is attached to said rod and protrudes through a first one of said loosely coiled sections of said outer shaft.

7. A device in accordance. with claim 6 wherein said first one of said loosely coiled sections is located toward said distal end of said'device and said at least one claw is attached to said rod at a point between said first one of said loosely coiled sec-' tions of said outer shaft and said distal end of said device.

8. A device in accordancewith claim 3 wherein said outer shaft includes a hollow cylindrical length of plastic tubing.

9. A device in accordance with claim 8 wherein said means enabling longitudinal relative movement between said outer shaft and said flexible rod includes at least one section of said outer shaft having a plurality of longitudinal strips substantially equally spaced around the circumference of said outer shaft and defining a plurality of slits substantially equally spaced around the circumference of said outer shaft.

10. A device in accordance with claim 9 wherein each of said strips is compressible into a curved surface having an apex, and f each of said claws includes said apex of one of said strips. ,W 11. A device in accordance with claim 10 wherein a first one of said sections of said outer shaft islocated toward said distal end of said 'deviee. v 12. A device in accordance with claim 1 wherein said outer shaft is attached to said rod at a first point and at a second point,

said first pointincluding the distal end of said device" and p said'second point including the proximal end of said device. 13. A device in accordance with claim 12 wherein said outer shaft includes a helically coiled-wire.

14. A device in accordance with claim 13 wherein said means enabling longitudinal relative movement between said outer shaft and said rod includes first and second loosely coiled sections of said outer shaft having convolutions spaced apart one from the other, a said first loosely coiled section being located toward said distal end of said device, an I said second loosely coiled section being located toward said proximal end of said device. 15. A device in accordance with claim l4 wherein said at least one claw is attached to said rod and protrudes through said first loosely coiled section of pipe, comprising tioned means includes at least one loosely coiled section of said spirally coiled wire wherein adjacent convolutions are spaced apart one from the other.

said outer shaft, said at least one claw being attached to said rod at a point between said first loosely coiled section and said distal end of said device.

16. A device in accordance with claim l2 wherein 5 said outer shaft includes a hollow cylindrical length of plastic tubing.

17. A device in accordance with claim 16 wherein said means enabling longitudinal relative movement between said outer shaft and said rod includes first and second sections of said outer shaft having a plurality of longitudinal strips substantially equally spaced around the circumference of said outer shaft and defining a plurality of longitudinal slits substantially equally spaced around said circumference said first section located toward said distal end of said device said second section located toward said proximal end of said device, and

said first and second sections being partially precompressed during assembly of said device.

18. A device in accordance with claim 17 wherein each of said strips is compressible into a curved surface having an apex, and

said at least one claw includes said apex of one of said strips. I

19. A device in accordance with claim 1 wherein said outer shaft is adapted for rearward longitudinal movement relative to said rod during insertion of 30 said device into said pipe, and

said claw is adapted for inward radial displacement from said outer shaft in response to said forward longitudinal movement.

20. A device in accordance with claim 1 wherein said outer shaft is adapted for forward longitudinal movement relative to said rod during withdrawal of said device from said pipe, and a said claw is adapted for outward radial displacement toward said outer shaft in response to said rearward longitudinal movement.

21. A device for cleaning the inside surfaces of a a flexible rod forinsertion inside said pipe,

a tubular outer'member fitted around said rod and connected to said rod at at least one point,

said outer member having a circumference smaller than the inside circumference of said pipe,

at least one claw attached to said device, said claw having a controllable radial displacement from said rod, and

means for enabling longitudinal movement of said rod relative to said outer member, said means operative for changing said radial displacement between said rod and said claw.

22. The device of claim 21 wherein said outer memher includes a spirally coiled wire.

23. The device of claim 22 wherein said last mensaid claw is attached to said rod at a point between said first one of said loosely coiled sections and said distal end of said device,

said claw protrudes through said first one of said loosely coiled sections at a point rearward of said point of attachment,

said radial displacement between said rod and said claw being increased during withdrawal of said device from said pipe and said radial displacement between said rod and said claw being decreased during insertion of said device into said pipe.

25. The device of claim 21 wherein said outer mem ber includes a hollow length of cylindrical tubing.

26. The device of claim 25 wherein said last mentioned means includes at least one section of said cylindrical tubing having a plurality of longitudinal strips substantially equally spaced around the circumference thereof and defining a plurality of longitudinal slits substantially equally spaced around said circumference.

27. The device of claim 26 wherein said device includesa distal end,

said outer member is connected to said rod at said distal end of said device,

a first one of said sections is located toward said distal end of said device,

each of said strips of said first one of said sections is compressible into a curved surface having an apex forming said claw,

said radial displacement between said rod and said claw being increased during withdrawal of said device from said pipe.

28. The device of claim 25 wherein said last mentioned means includes at least a first and a second section of said cylindrical tubing each having a plurality of longitudinal strips substantially equally spaced around the circumference thereof and defining a plurality of longitudinal slits substantially equally spaced around said circumference,

said outer member is connected to said rod-at the distal end of said device and at the proximal end of said device,v said first section is located toward said distal end of said device and said second section is located toward said proximal end of said device,

said first and second sections are partially precompressed during assembly of said device,

each of said strips of said first section is compressible into a curved surface having an apex forming said claw, and

said radial displacement between said rod and said claw is increased during withdrawal of said device from said pipe and decreased during insertion of said device into said pipe.

29. A device for removing an obstruction from a confined space, said device comprising an outer shaft of coiled wire,

an inner central member fastened to said outer shaft,

one or more claws attached to said inner central member and protruding from said outer shaft, and

means including coils of said outer shaft enabling longitudinal displacement of said outer shaft relative to said inner central member, such that said claws are retracted into said outer shaft during insertion of said device into said confined space and extended from said outer shaft during withdrawal of said device from said confined space, thereby enabling positive engagement of said obstruction. 30. A device in accordance with claim 29 wherein said last mentioned means includes at least one loosely coiled section of said outer shaft.

31. A device in accordance with claim 30 wherein said device includes a distal end, said loosely coiled section is located toward said distal end of said device, and said claws are attached to said inner central member at a point forward of said loosely coiled section. 32. A device for removing an obstruction from a confined space, said device comprising a hollow outer shaft having at least one compressible section, an inner central member fastened to said outer shaft in a manner to allow longitudinal displacement of said shaft relative to said inner central member by compression of said compressible section, and at least one claw arranged to radially extend from said hollow outer shaft a controllable distance, said distance controlled by said longitudinal displacement. 33. A device in accordance with claim 32 wherein said outer shaft includes a hollow length of cylindrical tubing.

34. A device in accordance with claim 33 wherein said device,includes a distal end, said inner central member is fastened to said outer shaft at said distal end of said device, said compressible section includes a plurality of Iongitudinal strips spaced substantially equally around the circumference of said outer shaft and defining a plurality of longitudinal slits spaced substantially equally around said circumference, each of said strips is compressible into a curved surface having an apex forming said claw, and said compressible section is located toward said distal end of said device. as indicated in FIG. 1, enabling attachment of various devices surface having an apex, and

PRINTER'S TRIM LINI Column (SEAL) Attest:

Claim 34,

EDWARD M.FLETCHER,JR. Attesting Officer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 757, 375 Dated September 11, 197} Inventor(s) Martin Strom It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

7, immediately following line /6, insert --outer shaft 50, which, upon longitudinal expansion, becomes narrowed or constricted, so that the outward radial displacement of

strips

56, 57, and 58 due to the precompression is reduced or eliminated, and the strips are brought essentiall; into alignment with the adjacent portions of shaft 50. As a result, the outer surfaces of outer shaft 50 are relatively uniform in circumference, with the exception of section 5 located toward the proximal end of the device, and the major portion of the device may thus easily be insertedinto a pipe, such as pipe 90, having an inner circumference greater than the outer circumference of outer shaft 50.--.

lines 17 l9, delete --as indicated in FIG. 1,

enabling attachment of various devices surface having an apex, and--.

Signed and sealed this 19th day of March 1974.

C. MARSHALL DANN Commissioner of Patents USCOMM-DC 60376-F'69 U.S, GOVERNMENT PRINTING OFFICE I969 0 36fl-334,

Claims

1. A device for cleaning the interior surfaces of an elongated pipe comprising, a flexible rod for insertion into said pipe, an outer shaft fitted around said rod, said outer shaft including means for enabling longitudinal movement of said shaft relative to said rod, and at least one claw extending from said device and having a controllable radial displacement from said outer shaft in response to said longitudinal movement.

2. A device in accordance with claim 1 wherein said outer shaft is attached to said rod at at least one point.

7. A device in accordance with claim 6 wherein said first one of said loosely coiled sections is located toward said distal end of said device and said at least one claw is attached to said rod at a point between said first one of said loosely coiled sections of said outer shaft and said distal end of said device.

8. A device in accordance with claim 3 wherein said outer shaft includes a hollow cylindrical length of plastic tubing.

10. A device in accordance with claim 9 wherein each of said strips is compressible into a curved surface having an apex, and each of said claws includes said apex of one of said strips.

11. A device in accordance with claim 10 wherein a first one of said sections of said outer shaft is located toward said distal end of said device.

12. A device in accordance with claim 1 wheRein said outer shaft is attached to said rod at a first point and at a second point, said first point including the distal end of said device and said second point including the proximal end of said device.

13. A device in accordance with claim 12 wherein said outer shaft includes a helically coiled wire.

14. A device in accordance with claim 13 wherein said means enabling longitudinal relative movement between said outer shaft and said rod includes first and second loosely coiled sections of said outer shaft having convolutions spaced apart one from the other, said first loosely coiled section being located toward said distal end of said device, and said second loosely coiled section being located toward said proximal end of said device.

15. A device in accordance with claim 14 wherein said at least one claw is attached to said rod and protrudes through said first loosely coiled section of said outer shaft, said at least one claw being attached to said rod at a point between said first loosely coiled section and said distal end of said device.

16. A device in accordance with claim 12 wherein said outer shaft includes a hollow cylindrical length of plastic tubing.

17. A device in accordance with claim 16 wherein said means enabling longitudinal relative movement between said outer shaft and said rod includes first and second sections of said outer shaft having a plurality of longitudinal strips substantially equally spaced around the circumference of said outer shaft and defining a plurality of longitudinal slits substantially equally spaced around said circumference said first section located toward said distal end of said device said second section located toward said proximal end of said device, and said first and second sections being partially precompressed during assembly of said device.

18. A device in accordance with claim 17 wherein each of said strips is compressible into a curved surface having an apex, and said at least one claw includes said apex of one of said strips.

19. A device in accordance with claim 1 wherein said outer shaft is adapted for rearward longitudinal movement relative to said rod during insertion of said device into said pipe, and said claw is adapted for inward radial displacement from said outer shaft in response to said forward longitudinal movement.

20. A device in accordance with claim 1 wherein said outer shaft is adapted for forward longitudinal movement relative to said rod during withdrawal of said device from said pipe, and said claw is adapted for outward radial displacement toward said outer shaft in response to said rearward longitudinal movement.

21. A device for cleaning the inside surfaces of a pipe, comprising a flexible rod for insertion inside said pipe, a tubular outer member fitted around said rod and connected to said rod at at least one point, said outer member having a circumference smaller than the inside circumference of said pipe, at least one claw attached to said device, said claw having a controllable radial displacement from said rod, and means for enabling longitudinal movement of said rod relative to said outer member, said means operative for changing said radial displacement between said rod and said claw.

22. The device of claim 21 wherein said outer member includes a spirally coiled wire.

23. The device of claim 22 wherein said last mentioned means includes at least one loosely coiled section of said spirally coiled wire wherein adjacent convolutions are spaced apart one from the other.

24. The device of claim 23 wherein said device includes a distal end, said outer member is connected to said rod at said distal end of said device, a first one of said loosely coiled sections is located toward said distal end of said device, said claw is attached to said rod at a point between said first one of said loosely coiled sections and said distal end oF said device, said claw protrudes through said first one of said loosely coiled sections at a point rearward of said point of attachment, said radial displacement between said rod and said claw being increased during withdrawal of said device from said pipe and said radial displacement between said rod and said claw being decreased during insertion of said device into said pipe.

25. The device of claim 21 wherein said outer member includes a hollow length of cylindrical tubing.

27. The device of claim 26 wherein said device includes a distal end, said outer member is connected to said rod at said distal end of said device, a first one of said sections is located toward said distal end of said device, each of said strips of said first one of said sections is compressible into a curved surface having an apex forming said claw, said radial displacement between said rod and said claw being increased during withdrawal of said device from said pipe.

28. The device of claim 25 wherein said last mentioned means includes at least a first and a second section of said cylindrical tubing each having a plurality of longitudinal strips substantially equally spaced around the circumference thereof and defining a plurality of longitudinal slits substantially equally spaced around said circumference, said outer member is connected to said rod at the distal end of said device and at the proximal end of said device, said first section is located toward said distal end of said device and said second section is located toward said proximal end of said device, said first and second sections are partially precompressed during assembly of said device, each of said strips of said first section is compressible into a curved surface having an apex forming said claw, and said radial displacement between said rod and said claw is increased during withdrawal of said device from said pipe and decreased during insertion of said device into said pipe.

29. A device for removing an obstruction from a confined space, said device comprising an outer shaft of coiled wire, an inner central member fastened to said outer shaft, one or more claws attached to said inner central member and protruding from said outer shaft, and means including coils of said outer shaft enabling longitudinal displacement of said outer shaft relative to said inner central member, such that said claws are retracted into said outer shaft during insertion of said device into said confined space and extended from said outer shaft during withdrawal of said device from said confined space, thereby enabling positive engagement of said obstruction.

30. A device in accordance with claim 29 wherein said last mentioned means includes at least one loosely coiled section of said outer shaft.

31. A device in accordance with claim 30 wherein said device includes a distal end, said loosely coiled section is located toward said distal end of said device, and said claws are attached to said inner central member at a point forward of said loosely coiled section.

32. A device for removing an obstruction from a confined space, said device comprising a hollow outer shaft having at least one compressible section, an inner central member fastened to said outer shaft in a manner to allow longitudinal displacement of said shaft relative to said inner central member by compression of said compressible section, and at least one claw arranged to radially extend from said hollow outer shaft a controllable distance, said distance controlled by said longitudinal displacement.

33. A device in accordance with cLaim 32 wherein said outer shaft includes a hollow length of cylindrical tubing.

34. A device in accordance with claim 33 wherein said device includes a distal end, said inner central member is fastened to said outer shaft at said distal end of said device, said compressible section includes a plurality of longitudinal strips spaced substantially equally around the circumference of said outer shaft and defining a plurality of longitudinal slits spaced substantially equally around said circumference, each of said strips is compressible into a curved surface having an apex forming said claw, and said compressible section is located toward said distal end of said device. as indicated in FIG. 1, enabling attachment of various devices surface having an apex, and