US2229745A - Surfacing machine - Google Patents

Description

'Jmzs, 1941. RFrKNHsLE'Y f 2,229,745,

SURFAC IN G MACHI Filed July 10, 1940 2 Shets-Sheeg 1 -Rlchard E neisleg Jan. 28, 1941. R. F. KNEISLEY 2,229,745

SURFACING MACHINE Filed July 10, 1940 2 Sheets-i-Shet 2 jwvcnfon Rlchard F. Knei'sley' mum Patented Jan. 28, 1941 UNITED STATES PATENT OFFICE 2,229,745 SURFACING MACHINE Application July 10, 1940, Serial No. 344,810 2 3 Claims.

This invention relates to surfacing machines, and particularly to small portable machines of this character adapted to be hand operated and employingrotary sanding disks.

The primary object of the invention is the provision of an improved rotary disk type of machine of this character which is small and compact to enable it to be easily held and operated by either one or two hands, thus admirably adapting it for the sanding of boats, building walls and other objects where hand operation is required, and which has few parts and these compactly arranged and easily accessible, thereby rendering the machine light in weight and enabling it to be easily and quickly repaired.

The invention is full described in the following specification, and one embodiment thereof illus trated in the accompanying drawings, in which Figure 1 is a side elevation of a machine embodying the invention; Figs. 2 and 3 are sections of portions thereof, respectively, on the lines 2-2 and 3-3 in Fig. v1; Fig. 4 is an enlarged fragmentary detail showing the manner in which the sanding disk is applied to the work and the flexing of the working edge thereof when in use; Fig. 5 is an enlarged central vertical section of the machine with parts broken away, and Fig. 6 is a side elevation of the gear unit removed from the machine, with parts broken away and with the abrading disk removed therefrom.

Referring to the drawings, l designates a hollow casing of small elongated form with its top and sides preferably curved or of inverted U- form in cross-section to adapt it tov be conveniently held in one hand during handling. The casing is divided lengthwise by a partition 2 into a gear compartment 3 and a motor compartment 4, the latter having an open outer end which is closed by an end cap 5, secured to the casing at each side thereof by an end screw 6. The gear compartment 3 is formed with a bottom 1 preferably inset slightly relative to the lower edge of the casing and having a large opening 8 substantially centrally disposed and closed by a plate 9. This plate is fitted into the opening, is flanged over the outer marginal edge wall thereof, and is secured thereto by screws Ill. The bottom of the motor compartment is closed, as shown at [2, in substantially the plane of the lower edge of the casing.

The motor armature I4 is disposed in the compartment 4 lengthwise of the casing and has its shaft l5 journaled at one end in the cap 5 in a suitable bearing l6 and at its other end in the partition 2 in a suitable bearing H. The commutator brushes 20, two innumber, are disposed in diametrically opposed relation, one at the top and one at the bottom of the cap 5, and are mounted in respective openings 2| in the cap. Each of the brush mountings,.in the present instance, includes an insulating bushing 22 fixedly mounted in the opening by a screw 23, a brush holding sleeve 24 slidingly mounted in the bushing for movements radial to the commutator and through the inner end of which the brush projects, and a screw 25 threaded from theouter end of the opening 2! into thasleeve 24 with its head shouldered against the bushing 22, so that a turning of the screw will effect adjustment of the sleeve in the bushing. 'A coiled compression spring 26 is disposed between the screw 25 and brush 20 to yieldingly hold the brush in engage- .ment with the commutator.

The mounting means for the lower brush is disposed in. inwardly set relation to the bottom I! of the casing I and access to the. screw 25 thereof is had through an opening 21 in said bottom. This latter openingis closed by a bushing 30 held in the opening by a set screw 3|, and into this bushing is screwed a sleeve 32 in which a snap switch of any suitable form for the motor circuit is disposed. This -switch is controlled by a rotary button 33 which is ex,- posed at the under side of the casing I, or, in the" present instance, at the'un'der side of the cap 5. The electric lead wires 35 enter the casing through an opening in the upper portion of the cap 5, as shown, one being connected to the upper brush sleeve 24 while the other is con-f nected to the lower brush sleeve through'the switchand interposed motor field coil 36, which latter is mounted in the lower portion of the 2 motor compartment 4. The switch button is protected by an extension 31 on the loweredge of the cap 5 and is of circular form in crosssection to extend-partially around the switch button 33 and is of a length1to extend below such button and serve as a-supporting foot for the rear end portion of the motor casing.

A ventilating fan 38 for the motor is mounted on the shaft iii in the forward part of the compartment 4, and circulation of air-is eii'ected through said compartment and casing and cap openings 39.

The plate 9 which closes the bottom opening 8 of the gear compartment has a vertically oilset shelf portion supported from the plate by a web or leg portion 4| disposed in offset relation to the centers of the plate and shelf. A spindle 42 is mounted for rotation in suitable bearings 43 in said plate and shelf, the spindle being supported in the bearings by a nut 44 at and shelf, is journaled a short shaft 1. This,

shaft flxedly carries a pinion ll between the plate and shelf and in driving mesh with a gear I! fixed to the spindle 42 also between the plate and shelf. This pinion and gear are preferably but not necessarily of spiral form. The shaft 41 at its upper end flxedly carriu a bevel gear llv in mesh with a bevel drive" pinion II on the projecting forward end portion of the armature shaft I5. It is thus apparent that the spindle 42 is driven at a considerably reduced speed from the armature shaft II through said shaft and gearing. It is also ap arent that the; spindle l2, shaft 41 and connected gearin'g, withthe exception of the drive pinion II, are carried by the plate I and shelf ll as a unit, so that it may be removed as an entirety from the casing to facilitate inspection and repairdor replacement of parts. g

The'abrading disk 80 comprises a metal hub portion I having an annular flange 82 near its upper end and having a'center opening through which the screw 45 is projected." The upper end of the hub is adapted to fit centrally around the lower end of the spindle 42, while its lower end is countersunk in' conical form to receive a conical clamping head 63 carried by the screw II. The disk has a rubber body portion 64 which is vulcanized to the metal hub OI so that it forms an integral connection therewith. The rubber body 84 projects a distance radially of the hub to form a flexible annular flange portion, being flat at itsunder sideand having the top of its projecting flange portion tapering to gradually narrow the depth of such portion to a comparatively thin edge where it meets with the bottom surface. To facilitate flexing of the extended portion of said body, along substantiallya straight radial line, the body is weakened adjacent to its point of connection with the hub flange 62 by the provision of an annular recess 65 in its top' surface. The provision of this recess provides the disk body with an annular toe portion which when pressed against the work with the diameter of the disk at an incline to the work surface permits a flexing of such toe portion in substantially a straight line at its under side, as illustrated in Fig. 4, and causes the pressure of the flexed toe portion against the work to be substantially uniform throughout the radial depth of the toe portion. This is found to be important and desirable in the use of machines of this character. The under side of the disk 60 is faced with a sanding disk 66 which is preferably slightly larger in diameter thanthe disk body' 64 and has its central portion pressed up into the conical body socket of the hub fil and clamped thereto by the clamping head 83 on the screw 45. I

To facilitate handling, the casing l is preferably provided on its .top'with a handle to be grasped by one hand and a knob II to be grasped by the other hand of the operator. In the present instance, the handle I0 is secured at its forward end by a screw 12 to a screw plug I! which is threaded into a grease filling opening in the top of the casing.

It is apparent that I have provided a simple and compact surfacing machine of the hand operated type; that the operating parts thereof may be easily and quickly assembled in the casing, and connected for operation, and that the parts are easily accessible for inspection, repair or replacement.

I wish it understood that myinvention is not limited to any specific construction or arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent, is:

1. In a machine of the class described, a hollow elongated casing having a cross partition dividing the interior of the casing into a rear motor compartment and a forward gear compartment, the bottom of the forward compartment having a removable part, a motor mounted in said rear compartment with its armature shaft disposed lengthwise of the casing and mounted at its forward end in said partition and at its rear end in the rear wall of the casing, an abrad ing disk carrying spindle journaled vertically in said removable part and extending into the gearing compartment, a drive gear on the forward end of said motor shaft within the gear compartment, and speed reducing gearing carried by said removable part and providing a driving connection between said gear and spindle when the removable part is mounted in the casing. said gearing and spindle being carried by and removable as a unit from the casing with said removable part.

2. In a machine of the class described, a hollow elongated casing having a cross partition dividing the interior thereof into a rear motor compartment and aforward gear compartment, said forward compartment having an opening in its bottom, a motor mounted in said rear compartment and having its armature shaft journaled at one end in said partition and projected forwardly therethrough, a drive gear on the forward end of said shaft, a plate 'removably closing said bottom opening, an abrading disk carrying spindle and a shaft carried by said plate in spaced paralled relation and projecting into said forward compartment, said spindle being projected outwardly through the plate, and gearing carried by said last mentioned shaft and spindle and providing a. driving connection between said drive gear and spindle, said spindle, shaft and gearing being carried by and removable as a unit from the compartment with said plate.

3. In a machine of the class described, a hollow elongated casing having a cross partition dividing the interior of the casing into a rear motor compartment and a forward gearing compartment, said motor compartment being open one disposed inwardly with respect to the outer end of its opening, a, rotatable snap switch for the motor removably mounted in the outer end of said lower opening with its control knob exposed below the bottom of the cap, said cap having a guard flange for the switch knob projecting downwardly from its lower edge at the rear of said knob, an abrading disk carrying spindle projectlng through and journaled in the bottom of said forward compartment and projecting up into the compartment, and speed reduction means connecting the forward end of 5 said shaft to said spindle.

RICHARD F. KNEISLEY.

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