US3450003A - Ram with supplementing intake means - Google Patents

Description

June 17, 1969 w. w. NIGHTINGALE 3,450,003

RAM WITH SUPPLEMENTING INTAKE MEANS Filed Jan. 5, 1967 Wesley WN igh 1'1 n gale INVENTOR United States Patent 3,450,003 RAM WITH SUPPLEMENTING INTAKE MEANS Wesley W. Nightingale, Rte. 2, Box 163, Creswell, Oreg. 97426 Filed Jan. 3, 1967, Ser. No. 606,829 Int. Cl. Fb 15/22, 21/04; F16k 15/14 US. C]. 91-26 8 Claims ABSTRACT OF THE DISCLOSURE A ram cylinder, piston, and head assembly which provides relatively unrestricted inflow of working fluid at the start of a stroke and cushioning at the end of a stroke. The head assembly includes reed-type closure valves which open to provide relatively unrestricted inflow at the start of a stroke. The head assembly is formed of multiple block elements stacked against each other with the closure valves mounted on one of such elements.

This invention relates to a fluid-Operated ram, and more particularly to such a ram with novel means for providing for relatively unrestricted inflow of working fluid at the start of a stroke, as well as providing for cushioning of the piston in the ram at the end of a stroke.

Rams where provision is made for cushioning the piston at the end of a stroke by controlling the exhaust of working fluid, are well known. A deficiency of such rams is that the means controlling exhaust resulting in cushioning tends to interfere with the inflow of working fluid at the start of a stroke increasing the response time of the ram. In an effort to overcome such a deficiency, by-pass passages providing for inflow of working fluid have been controlled by spring biased ball checks. Such a construction has several limitations. For one thing, it is diflicult because of space limitations and for economic reasons to install a sufiicient number to produce the high rate of inflow needed for truly fast response. Further, ball checks and spring biased poppet checks, on contin ued usage, tend to break down and are themselves somewhat slow in response by reason of considerable mass in the moving parts.

A general object of this invention is to provide improved means in a ram for achieving a high rate of inflow of working fluid whereby a short response time may be realized.

A related object is to provide means enabling relatively unrestricted inflow of working fluid to a ram cylinder, providing for inflow independently of the passage system which produces cushioning in the device.

The advantages of the invention are particularly apparent with relatively short stroke rams, wherein cushioning of the ram piston takes place over a significant part of the total stroke afforded the piston.

Other objects and features comprise the provision in a ram of a reed-type closure valve controlling fluid flow in a path or course leading to an end of the ram, which path supplements another supply passage for fluid to such ram end.

A still further feature and object is to provide a fluid operated ram having multiple passages providing such supplementing courses for flow fluid, which passages are hydraulically in parallel. Such multiple passages assure that a fast rate of inflow of operating fluid takes place on the start of a piston stroke.

A related object is to provide such a ram where such multiple passages are distributed circumferentially about the axis of the ram, and to provide a reed-type closure valve for each passage with such so organized as to make possible a compact structure for the ram.

Yet another object and feature is to provide multiple block elements in a ram head assembly, which are stacked against each other in assembly. The organization permits simplification in the production of complex passages which are provided in the head assembly, and contribute to ease of maintenance.

Various other novel features and objects of the invention will become more apparent as the following description is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevation of a ram constructed according to an embodiment of the invention, having a portion broken away better to illustrate the construction of the rams head assembly and piston;

FIG. 2 is a cross-sectional view, taken generally along the line 22 in FIG. 1, and on a slightly larger scale, illustrating the positioning of a reed-type closure valve; and

FIG. 3 is a cross-sectional view, on the same scale as FIG. 2, taken generally along the line 3-3 in FIG. 1.

Referring now to the drawings, at 10 is indicated generally a double-acting fluid-operated ram. In the embodiment illustrated, such ram includes an elongated hollow cylinder 12, a reciprocable piston 14 mounted within the cylinder, a left cylinder head assembly 16 secured t and closing ofl? one end of the cylinder, a right cylinder head assembly 18 secured to and closing oil on opposite end of the cylinder, and a piston rod 20 secured to piston 14 and extending outwardly from opposite faces 24, 26 of the piston through opposing cylinder head assemblies 16, 18.

A fluid-tight seal sealing the piston and the interior wall of the cylinder is produced by a series of piston rings 22a, 22b, 22c, which encircle the piston. A pair of substantially cylindrical closure devices 28a, 28b are secured to and encircle the piston rod adjacent opposite faces of the piston. The cylinder and head assemblies 16 and 18 defiine a chamber 38 within which the piston, closure devices and portions of the piston rod may reciprocate.

Connected to cylinder head assemblies 16 and 18 are supply conduits 40, 42, respectively. Each conduit is connected at one end to a head assembly while an opposite end is connected through a valve means (not shown) to a suitable source of fluid under pressure, such as a compressed air supply (also not shown). By actuation of such valve means fluid under pressure may be admitted to either end of the ram, with an exhaust path for fluid provided the opposite end of the ram.

In the embodiment of the invention illustrated, head assemblies 16, 18 are identically constructed, and are secured to cylinder 12 in an identical manner. In view of the above, only one head assembly will be described in detail.

In the embodiment illustrated, each head assembly (and referring to assembly 16) comprises three stacked and separable block elements, detachably connected together. Specifically, such block elements comprise a first block element 50, a second block element 51, and a third block element 52.

First or outer block element 50 forms the outside of the assembly, and has a bore 53 therethrough concentric with the cylinder axis which slidably receives piston rod 20. Viewing an end of the ram, block element 50 has essentially the outline of elements 51, 52, which is square as can be seen with reference to FIGS. 2 and 3. Adjacent each corner of block element 50 is a bore 54 paralleling the cylinder axis receiving the end of a head retainer rod 55.

An annular passage 58 is formed on the inner face of the outer block element. Passage 58 is concentric with bore 52, and has an outer radius somewhat less than the radial spacing of bores 54 from the axis of the ram so that the passage extends continuously around the head assembly without intercepting bores 54.

The second or intermediate block element 51 abuts block element 50. Bore 72 adjacent each of its corners receives a head assembly retainer rod 55. Block element 51 has a bore 64 extending through it, which is concentrio with the ram axis. The bore has a diameter greater than the inner diameter of annular groove 58 in the outer block element and thus overlaps inner marginal portions of such groove as best seen in FIG. 1. A series of ports 70 extend through block element 51 with axes paralleling about that axis of the ram with a set of ends communicating with annular passage 58. These reports are shown in cross section in FIG. 1 and in dotted outline in FIG. 2.

Third or inner block element 52 abuts cylinder 12. Sealing the two together is a seal 71. Face 73 on the outer side of the element 52 abuts intermediate element 51. An annular shoulder shown at 74 extends through bore 64, and abuts the inner face of outer block element 50. Adjacent each corner of element 52 is a bore 85 paralleling the ram axis receiving a head assembly retainer rod.

Block element 51 includes a hollow central region 86 formed of bores of varying diameters shown at 87, 88, 89, 90. Bore 90 contains packing material 91 sealing the piston rod and head assembly. Bore 89 loosely receives rod 20. Bores 87 and 88 are adapted to receive closure device 28a with movement of the piston to a position adjacent the head assembly. Bore 87 has essentially the diameter of device 280: so that a snug fit is produced with device 28b extending through the bore. Bore 88 has a somewhat larger diameter to permit the passage of fluid thereabout with device 28a extending into the bore.

A supply port 92 extends radially into element 52 and connects at its upper end with bores 87, 88. Supply conduit 40 connects with the lower end of port 92. An annular groove 94 is recessed inwardly from the left face of block element 52, which is concentric with the ram axis, and interconnects with port 92. The open side of the groove communicates with the outer margins of bore 64 in element 51. A second annular groove 96 is also recessed in the left face of block element 52, concentric with the ram axis, and this groove has an open side facing and communicating with a set of ends of circumferentially distributed ports 70 in blocks 51.

A series of bores 98 are circumferentially distributed about the axis of the ram, extending from annular groove 96 to the right face of block element 52 in FIG. 1. Fluid flow is accommodated from one of the bores 98 described into annular groove 94 through radially extending passage 101 illustrated in the upper part of the figure in FIG. 1. As later brought out, this passage constitutes a by-pass channel in the invention. Controlling flow through the passage is a pin 102, also referred to herein as a regulable metering valve, illustrated with its tapered lower end partially projecting into one end of the passage. Pin 102 has a threaded head 102a screwed into an internally threaded bore 100 extending inwardly from one side of element 52. A seal 103 seals the pin in element 52 in a region outwardly from bore 98.

Mounted on the right-hand face of block element 51, and located within groove 96 with the block elements stacked together in a completed head assembly as shown in FIG. 1, are a series of reed-type closure valves 104. As is best shown in FIG. 2, each of these valves comprises an elongated, resilient, deformable blade element which is secured to block 51 by a bracket 106 and a screw 108. The ends of each blade element rest flush against block element 51 and extend outwardly from bracket 106 to cover ports 70. All of ports 70 in block elements 51 are so covered. The blade elements are deflected so as to move away from covering positions over the ports when the pressure of fluid on port 70 exceeds the pressure of fluid in groove 96.

As is best shown in FIG. 3, an annular screen 112 is 4 mounted within annular groove 96 which covers bores 98. Mounting brackets 114 and screws 116 secure the screen to block 52.

The entire head assembly 16 is secured to an end of the cylinder 12 by head assembly retainer rods 55 which extend the length of the ram and through bores such as those described at 54, 72, and 85. The ends of these rods are threaded to receive nuts 122, which when advanced on the retainer rods clamp the head assemblies to the cylinder.

The grooves and ports within the head assembly define a fluid passage means comprising two courses for fluid flow which are hydraulically in parallel. A first course for the flow of fluid to the inside of the ram extends from the supply conduit 40 into supply port 92, thence through annular groove 94, outer margins of bore 64, annular passage 58, ports 70, annular groove 96, and finally through bores 98 into the ram. A second course for the flow of fluid to the inside of the ram is from the supply conduit 40, through supply port 92, and thence through bores 88 and 87 into the cylinder chamber.

Explaining the operation of the ram, it will be assumed that the piston is to be moved in a stroke to the left in FIG. 1. To move the piston, fluid under pressure is supplied through conduit 42 and permitted to exhaust through condiut 40. Considering for the moment only how exhaust from the ram takes place, as the piston advances toward head assembly 16, blade elements 104 are forced by fluid pressure into covering positions over ports 70, and fluid leaves the ram primarily through the second course described, or through ports 87, 88. A minor amount of exhaust flow is permitted through partially closed by-pass channel 101. When the piston reaches the point at which closure device 28a enters bore 87, bore 87 is substantially closed off, and at this point such exhaust of fluid as does take places occurs through the partially closed by-pass channel and by leaking past device 28a, at a sharply reduced rate. A mass of fluid tends to be entrapped within the left end of the ram providing a cushion absorbing the momentum of the piston, preventing it from striking the head assembly with full force.

In a return stroke, and describing how the supply of fluid to the ram takes place, fluid under pressure enters through supply conduit 40, and thence is admitted to the inside of the ram by flowing through each of the two fluid courses described. Initially, and with the piston directly adjacent head assembly 16, closure device 2811 by closing off the bore 87 limits the effective area against which the fluid may act upon to an area equalling the cross-sectional area of bore 87 minus the cross-sectional area of the piston rod. The fluid course provided by grooves 94, 58 and bores 98, however, accommodate a rapid inrush of fluid to the inside of the ram, whereby the fluid may act upon the full face of the piston. With fluid under pressure admitted to groove 94, blade elements 104 are deformed with their ends moving off of ports 70, to enable fluid to flow freely through bores 98.

It will be seen from the above that the invention contemplates a ram with means for cushioning the piston near the end of a stroke, so constructed that this cushioning is not at the expense of sacrificing fast movement of the piston away from the head assembly of the ram in a subsequent return stroke. The construction described, providing as it does multiple bores 98 distributed circu-rnferentially about the rams axis, permits a relatively large volume of fluid under pressure to be admitted to the interior of the ram substantially immediately upon pressure fluid being supplied the head assembly at the end of the ram, and thus the full face of the piston is utilized substantially instantaneously as the effective area against which fluid under pressure acts upon in starting a stroke.

With the reed-type closure valve disclosed controlling flow through the ports or passages 70, the ports open fully substantially instantaneously with fluid under pressure admitted to the ports against the backsides of the blade elements which form the reed-type closure valves. The reed-type closure valves can take repeated cycling without disintegration of the blade elements or impairment of their operability. In the event that a blade element should break apart, fragments of such element are prevented from entering the ram by the screen described at 112. With the blade elements providing closure of the ports 70 and occupying as they do a plane which extends generally perpendicularly to the ram axis, a compact organization is possible with the inclusion of a number of such ports and without excessive elongation of the ram.

With the head assemblies comprising separable block elements, block element 51, which includes ports 70 and the blade elements for closing these ports, may readily be removed from that assembly for replacement of the blade elements should such be necessary. This also exposes screen 112.

It is claimed and desired to secure by letters patent:

1. A fluid-operated ram comprising an elongated hollow cylinder, a relatively reciprocable piston mounted in said cylinder, a head assembly closing off one end of the hollow cylinder, fluid passage means connected to the interior of said cylinder for supplying fluid to and exhausting fluid from said cylinder comprising first and second courses providing parallel flow paths connecting with the cylinder, said first course comprises a passage formed in the head assambly extending about the axis of the ram and multiple ports distributed about the axis of the ram communicating with said passage, and reed-type closure valve means controlling flow through the first of said courses only, said closure valve means comprising plural deformable blade elements distributed about the axis of the ram adapted to close said ports during the exhaust of fluid from the cylinder and further adapted to open said ports during the supply of fluid to said cylinder.

2. The ram of claim 1, wherein said ram further includes a closure device for closing said second course, said piston is adapted to reciprocate away from and toward said head assembly during the supply and exhaust of fluid, respectively, and said closure device precedes the piston in its travel toward said head assembly and closes off said second course on approaching the head assembly.

3. The ram of claim 1, wherein said head assembly comprises at least two separable block elements detachably connected together, and one of said block elements has said deformable blade elements mounted thereon, which are exposed on seperation of the block elements.

4. The ram of claim 3, wherein said passage is annular and the other of said block elements has an annular groove therein which is opened up on separation of the block elements, said annular groove overlying said deformable blade elements and forming part of said first course.

5. The ram of claim 4, wherein multiple axially extending bores in said other block element connect said annular groove and the interior of said cylinder, said bores forming part of said first course, and which further comprises screen means mounted in said groove screening fluid flow into said bores.

6. The ram of claim 3, wherein the block elements follow one another along the axis of the ram and the blade elements exposed on separation of the block elements occupy planes substantially normal to the axis of the ram.

7. The ram of claim 1, wherein said first course further comprises a by-pass channel which by-passes said ports and a regulable metering valve for controlling the flow of fluid through said by-pass channel.

8. The ram of claim 1, wherein said head assembly comprises at least two separable block elements detachably connected together, one of said block elements has said deformable blade elements mounted thereon with such disposed in a plane extending generally perpendicular to said ram which are exposed on separation of the block elements, the other of said block elements having an annular groove which overlies said blade elements with the block elements connected together and provides a space for receiving the blade element on such being deformed.

References Cited UNITED STATES PATENTS 666,145 1/1901 Kennedy 137-525.5 1,299,761 4/1919 Nelson 137-5255 2,610,064 9/1952 Goddard 137-5255 3,033,169 5/1962 Norwood 91-26 3,218,934 11/1965 Daniels 91-26 3,303,746 2/1967 Schmoeger 91-26 3,267,815 8/1966 Ortman et a1. 91-26 FOREIGN PATENTS 650,642 2/ 1951 Great Britain.

PAUL E. MASLOUSKY, Primary Examiner.

US. Cl. X.R. 91-396; 92-78, 164; 137-5255

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