US2400330A - Controlling device - Google Patents

Description

May14, 1946. R.- o. ALLEN 7 2,400,330

' CONTROLLING fjEvlcE' Filed Au .-'27, 1945 INVENTOR- Roy dill/Dem Patented May 14, 1946 CONTROLLING nnvroE Roy 0. Allen, Athens, Pa., assignor to Ingersoll- RandcCompany, New York, N. Y., a corporation of v New Jersey Application August 27, 1943,: Serial 'No.:500, 243

4Claims. (o1. 121-f-35r' This invention relates to fluid actuated'tools, and more particularly to a controlling device for a fluid actuating riveting machine of the percussive type having a mounting to slidably support the riveting machine with respect to the work.

One object of the invention is to assure uniiormity of the shapes of the portions of the'rivets formed by the machine.

Another object is to obviate the-chances of operating the machine longer than is actually necessary to perform the work of upsetting the rivet. I

part pointed 'out hereinafter.

In the drawing accompanying this specification and in which similar reference numerals refer to similar parts,

Figures '1 and 2 are longitudinal elevations; partly in section, of a riveting machine embodying the invention and showing the various movable parts of the machine in different positions which they may occupy in practice,

Referring more particularly to the drawing, 20

designates a fluid actuated power unit shown as being in the form of a riveting machine,jand..2l

is a sample of work upon which'the riveting machine may operate.

The riveting machine is arranged slidably in a casing 22 havingi'a bracket 23 fastened thereto by'bolts 24 to support the work 2|. .A arm,25

of the bracket 23 extends across the plane of movement of the riveting machine and contains an anvil block 26 having a recess 21 to ac'com modate the preformed head of a rivet 28in'the work2l.

The riveting machine 20 is of a conventional type and comprises, as casing parts, a cylinder 29 and a head block 30 threadedly connected to the cylinder. The cylinder has a piston chamber at anda hammer piston 32 reciprocable therein for actuating a rivet set 33 the stem of which extends slidably into the front end of the cylinder 29 to receive the blows of thehammer piston 32,

Other objects will be in part obvious and in opening 38 to convey the exhaust fluid to'the atmosphere.

The peripheralsurface 39 of 'thehead block 3!! has a nice sliding fit on the surface of the bore 36 and a sealing ring 40 in the head block prevents the leakage of fluid along the cooperating surfaces of the head block and the bore 36. The

riveting machine is additionally guided in the casing 22 by a bushing 41 in the front end of the casing to guide the forward portion of the cylinder 29, and ports'42' in the bushing 4| provide additional outlets for 'ex-haust'fiuid from the front end of the bore 36. The wall of the bushing is grooved to provide a seating surface 43 for an end of a spring 44 which encircles the cylinder and seatsat its other end against a flange 45 on the periphery of the cylinder 29.

-The riveting machine, when idle, is held in its rearmost limiting position in the bore 36' by the spring 44 but is actuated toward the work by pressure fluid. To this end the casing is provided with a small bore 46- rearwardly of the boref36 into which itopens and in the bore 46 is a plunger 4'! having a pressure surface 48 against which pressure fluid may act for moving the riveting machine in a forwardly direction; On theoppo- I site end of the plunger 41 is a reduced stem 49 that seats" againstthe rearward end of the'head block 30 constituting, in the constructionshowm a pressure surface. V

I he pressure fluid serving to-actuate the power unit and drive it forwardly in the casing 22 is introduced into thecasing by a supply conduit 5- that opens into a supply passage 52 leading to the chamber 36. A valve 'chamberiiti intersects the supply passage 52 and from it leads a passage 54 to the rearward end of the bore 46. The passages 52 and Mare controlled by a rotary thrOttlevalve-ES in the valve chamber 53, having a lever 56 for its manipulation. In the periphery of the valve is'a partly annular grooved? to simultaneously afford communication between the several branches of the supply passage 52 lying on opposite sides of the valve chamber 53 and with the passage 54 in theopen position of the'valve 55. The valve 55 also controls the exhaust of fluid from the bore 45 and to thisend is provided with a passage 58 that extends diagonally through the valve to coin-r municate atone end with the passage l d at it s'oth'er end with a free exhaust port it in the casing 22.

Means are provided to effect the automatic cut off of pressure fluid to the chamber 3'5 and thus to the power unit for stopping the operation of the latter when the work has been completed and in that way avoid the waste of power medium by continuing to deliver blows after the rivet has been suitably formed. To this end the casing 22 is provided with a valve chest 60 having a bore constituting a valve chamber 6| the outer end of which is sealed by a plug 82.

The valve chamber 5| comprises an enlarged portion 63 and a reduced portion 64 that intersects the portion of the supply passage 52 lying between the valve chamber 53 and the chamber 36. The valve chamber BI contains a reciprocatory valve 85 comprising a head 86 that lies in the enlarged portion 63 and a stem 61 in the reduced portion 84 to control the supply passage 52. In the periphery of the stem 81 is an annular groove 68 to afford communication between the branches of the supply passage 52 lying on opposite sides of the valve chamber in a limiting position of the valve 65. The innermost end of the valve chamber 6| is preferably vented to the atmosphere through a passage 59 in the casing 22.

The valve 65 is actuated to its different control ling positions by pressure fluid and the end surface of the head 68 adjacent the stem 81 and the outer enlarged end surface of the head accordingly constitute actuating surfaces 18 and 1| against which pressure fluid acts for shifting the valve. Such pressure fluid is conveyed from the supply passage 52, at a point between the valve chambers BI and 53, by a passage 12 that leads to a recess 13 in the valve chest fifl and has a branch passage 14 leading to the innermost end of the enlarged portion 53 of the valve chamber 81. A port 15 aflords communication between the recess 13 and the valve chamber 6| for supplying pressure fluid to the actuating surface 1|.

In the form of the invention shown, the flow of pressure fluid from the recess 13 through the 1 port 15 is controlled by a throttle valve 16 of the poppet type, the head 11 of which cooperates with a tapered seating surface 18 at the juncture of the recess 13 and the port 15. A spring 18 in the recess 13 acts against the head 11 for pressing it against the seating surface 18.

The stem 88 of the throttle valve 16 extends transversely through the valve chamber BI and through bores 81 and 82 in the valve chest 88 and the bracket 23, respectivcly, whereby the throttle valve 18 is held in coaxial relationship with the seating surface 18. In the stem 80 adjacent the head 11 of the throttle valve is a portion 83 of reduced diameter to permit the free flow of pressure fluid through the port 15. The portion 83 is also of such length that in the seated position of the throttle valve said portion 83 extends into the bore 82 and cooperates therewith to provide an annular space 84 for communicating the valve chamber 8| with an atmospheric exhaust port 85 in the valve chest.

The exhaust port 85 is so positioned that when the throttle valve 16 rests upon its seat it will be in free communication with the valve chamber through the annular space 84 but will beblanked oiT by the main body portion of the stem 88 when the throttle valve is unseated.

The force employed for unseating the throttle valve 15 is applied by the power unit 20 and is transmitted to the throttle valve by a rocker bar 88 supported by a bracket 81 on the casing 22. The rocker bar is pivotally mounted upon a pin 88 in the bracket 81 and extends with one end 89 through the opening 38 into the path of the flange 45 on the cylinder 29. The opposite end 98 of the rocker bar overlies the free end of the valve stem 88 for engagement therewith to unseat the throttle valve 16- whenever the rocker bar 86 is tilted by the flange 45.

In the operation of the device and assuming the various parts of the machine to occupy substantially the positions shown in Figure 1, the throttle valve 55 is first rotated to establish communication between the supply passage 52 and the passage 54. Pressure fluid will then'flow into the bore 46 against the pressure surface 48 and move the riveting machine 20 forwardly in the casing 22 until the rivet set 33 seats against the rivet 28.

' The riveting machine will move readily in this direction without creating a sub-atmospheric pressure in' the chamber 38 since the said chamber will then be in communication with the atmosphere through the passages and chambers in the riveting machine, the bore 36 adjacent the cylinder 28 and the opening 38.

After the work has been correctly positioned with respect to the rivet set the valve 55 is rotated further in the same direction until the groove 51 communicates the several branches of the supply passage 52 with each other. Pressure fluid then flows into the rearward end of the chamber 36 against the pressure surface 50 to hold the rivet set firmly against the work and to set the riveting machine 28 in operation.

In this position of the throttle valve 55 pressure fluid will then also enter the recess 13 and the inner end of the enlarged portion53 of the valve chamber 6| and hold the valve 65 firmly in position to maintain the annular groove 68 in the valve stem in registry with the adjacent portions of the supply passage 52 so that the chamber 38 will be in free communication with the source of pressure fluid supply.

The riveting machine and the plunger 41 will then be held in the relative positions described by the pressure fluid acting against the pressure surfaces 48 and 58, and the percussive element and the pressure fluid distributing element of the riveting machine will continue operating as long as the valve 65 remains in the open position. Duringthe upsetting of the rivet 28 the riveting machine 20 will move gradually forwardly and at about the time the rivet is suitably upset the shoulder 45 will engage the rocker bar 86 and rock it about the pivot 88.

This movement of the rocker bar will drive the end thereof against the stem 80 of the throttle valve 18 and raise the head 11 from the seating surface 18. At the same time the main body portion of the valve stem 80 will overlie the exhaust port 85. Pressure fluid will then flow from the recess 13 through the port 15 into the outer end of the valve chamber BI and shift the valve 65 inwardly thereby moving the annular groove 88 out of registry with the supply passage 52 and moving the adjacent portion of the valve stem 61 across the ends of the supply passage 52 and thus cut-off the further admission of pressure fluid into the chamber 38. 7

Any pressure fluid thereafter remaining in the chamber 38 will then pass through the riveting machine to the atmosphere. The riveting machine will, however, be held against the rivet by the pressure fluid acting against the actuating surface 48 of the plunger 41 until the throttle valve 55 is rotated to move the groove 51 out of registry with the passage 54 and to place the passage 58 Ma position to communicate the passage 54 with the exhaust port 59 for exhausting pressure fluid from the bore 46. The spring 44 will then drive the riveting machine 20 rearwardly to its initial position and release the rocker bar and thus also the valve stem 80. v

The spring 19 will then return the throttle valve 16 to its seat and at the same time the exhaust port 85 will be uncovered to permit the escape of the pressure fluid acting against the actuating surface H. The valve 65 is then free to be moved into position for opening the portion of the supply passage 52 between the throttle valve 55 and the chamber 36 when the throttle valve 55 is again manipulated to supply pressure fluid to the chambers 46 and 36.

I claim:

1. A fluid actuated tool, comprising a casing having a pressure chamber and a supply passage for pressure fluid opening into the pressure chamber, means slidable in the casing having a pressure surface subjected to the pressure fluid in the pressure chamber, a pressure fluid actuated valve for controlling the supply passage, a throttle valve for controlling the supply of pressure fluid to the said fluid actuated valve, and a valvelifter actuated by the first mentioned means during movement thereof in the casing for actuating said throttle valve in one direction. 7

2. A fluid actuated tool, comprising a casing having a pressure chamber and a pressure fluid supply passage opening into the pressure chamber, means slidable in the pressure chamber having a pressure surface subjected to pressure fluid in the pressure chamber, a pressure fluid actuated valve for controlling the supply passage,

3. A fluid actuated tool, comprising a casing having a pressure chamber and a pressure fluid supply passage opening into the pressure cham ber, means slidable in the pressure chamber having a pressure surface subjected to pressure fluid in the pressure chamber, a valve chamber in the casing, a fluid actuated valve in the valve chamber for controlling the supply passage having opposed differential actuating surfaces, the smaller actuating surface being normally subjected to pressure fluid for holding the valve in position to permit the flow of pressure fluid to the pressure chamber, a throttle valve to valve pressure fluid to the actuating surface of larger area for moving the fluid actuated valve into position to cutoff the flow of pressure fluid to the pressure chamber, and a rocker bar actuated by the first said means during movement thereof in the casing for actuating the throttle valve.

4. A fluid actuated tool, comprising a casing having a pressure chamber and a pressure fluid supply passage opening into the pressure chamber, means slidable in the pressure chamber having'a pressure surface subjected to pressure fluid in the pressure chamber, a valve chest'having a valve chamber and inlet and exhaust ports for the valve chamber, a valve in the valve chamber having opposed differential actuating surfaces the a throttle valve for controlling the supply of presthe throttle valve to a position for valving pressure fluid to the fluid actuated valve.

smaller of which is normally subjected to pressure fluid for holding the valve. in position to per-V mit the flow of pressure fluid to the pressure chamber, a throttle valve to valve pressure fluid through the inlet port to the actuating surface of

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