US1720435A - Shank and bit punch - Google Patents

Description

July 9, 1929. E, PETERS Ei- AL I 1.720.435 SHANK AND BIT PUNCH Filed Sept. 9, 192'? E QQ Ms w fi k :1

Patented July 9, 1929.

lll'l'llD STATES PATENT OFFlCE.

ARTHUR E. PETERS, UF PHILLIPSBUBG, NlJlW JERSEY, AND JESSE DITSON, OF LITTLE- IUN, COLORADO; ASSIGNGBE TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEVJ JERSEY, A CORPORATION OF NEW JERSEY.

SHANE AND BIT PUNCH.

Application filed September This invention relates to devices for rei orming the bores of hollow articles, but more particularly to a fluid actuated device for pinning out the ends of the bores in drill steels and other similar articles in which the entrance of the bores frequently become restricted during the preceding sharpening operation.

One object of the invention is to drive a punch pin into the bore of a drill steel and withdraw it therefrom by rapidly repeated blows of the hammer piston against the anvil block whereby the punch pin is carried.

Another object is to provide aconvenient means for controlling the admission of pressure fluid into the percussive element of the punch.

Other objects will. be in part obvious and in part pointed out hereinafter.

In the drawings showinga preferred modification of the invention,

Figure 1 is a longitudinal sectional elevation of a shank and bit punch constructed in accordance with the practice or the invention and showing the parts in position for driving the punch pin into the work,

F igure 2 is a view similar to Figure 1 il lustrating the position of the parts for withdrawing the punch pin from the work,

Figure 3 is a transverse view of the centering chuck taken through Figure 1 on the line 3-3 looking in the direction indicated by the arrows, and

Figure 4 is a similar view of the throttle valve lever taken through Figure 1 on the line iti looking in the direction indicated by the arrows.

Referring to the drawings, A designates the cylinder of a shank and bit punch and B the piston chamber in which is disposed a reciprocatory hammer piston C. The piston chamber B comprises an enlarged forward portion D and a rearwardly reduced portion E. The piston C is proportioned accordingly and its rearward reduced portion F in this instance is constantly exposed to pressure fluid during the operation ofthe machine.

Disposed at the front end of the cylinder A and projecting partly thereinto is a front head G which may be secured in operative position in any suitable manner as for instance by the usual side bolts (not shown). The rearward end of the cylinder A is sealed 9, 1927. Serial N0. 218,465.

by a back cylinder wasl'ier H which :torms a seat for and serves to centralize a cylinder cap J with respect to the cylinder.

On one side of the cylinder A is formed a tapered valve chamber K to accommodate a correspondingly tapered throttle valve L having a passage 0 in constant communication with pressure fluid conveyed to the throttle valve from any suitablesource of supply by a connection P. The throttle valve L in this instance is provided with a stem Q; which is supported at its outer end. by a bearing It preferably formed integrally with the cylindcr A and so spaced with respect to that portion of the cylinder wherein the valve chamber K is formed as to form a space S of suitable proportions to receive a throttle valve lever T whereby the throttle valve L may be manipulated.

The throttle valve lever T comprises oppositely extending portions U and V curved slightly at their ends to prevent deflection of such instrument or means as may be e1nployed for manipulating the throttle valve. Intermediate the ends of the throttle valve lever is formed a bore TV to receive slidably the stem Q, and in one side of the lever adjacent the bore W is formed a slot X to permit contraction of the lever at this point for the purpose of clamping said lever to thestem Q. The means whereby this clamping eitiect is obtained in the present instance consist of a bolt Y which engages a notch Z in the stem Q, and has threaded on one end a nut 5 whereby the desired clamping etlect may be obtained.

In its assembled position, the throttle lever T will be inclined both in the open and closed positions of the throttle valve L, the degree of. rotation of said throttle valve being limited by the cylinder in the bottom of the space S which forms an abutment for the throttle lever on opposite sides of the stem: Q.

In one side of the throttle valve L is a port 0 to afford communication between the passage 0 and a port d in the cylinder A for the passage of pressure fluid into the piston chamber B. The port d is in constant communication with a passage 6 having rear ward and forward ports 7 and 9 both of which open into the reduced bore E of the cylinder.

As is customary in devices employing pie A portion D of thepiston chamber B for impellingithe piston forwardly.

Pressure fluid is conveyed to the end of the piston chamber B for impcllr the piston C rearwardly through an inlet passage is which opens into the piston chamber B near its front end and has its entrance end 0 intermediate the ports and 9.

Intermediate the ends of the enlarged portion D of the piston chamber B is formed an exhaust port p for exhausting the pressure fluid from both ends of the enlarged portion D, said exhaust port being controlled by the head of the piston C.

Extending slidably through the front head, the cylinder and the piston an anvil block g having a recess r in its front end to receive a punch pin 8 adapted to be driven into a hollow drill steel The punch pin 8 may be secured in the anvil block 9 in any suitable manner, in the present instance a pin at extending transversely through the anvil block and the punch pin is used for this purpose.

' The anvil block g illustrated is of a length to extend through the cylinder A and, in its retracted position through the cylinder cap J. The anvil block is guided in this instance near its front end by the front head G and at a point near its rearward end by the back cylinder washer H.

Near the front end of the anvil block 9 is a collar 0) which when the anvil block Q is in its rearwardmost position, extends into the path ofthe'piston C to' receive the blows thereof for driving the punch pin 8 into the drill steel 2/. Somewhat similar means are provided for exposing the anvil block 9 to the blows of the piston C for driving said anvil block in a rearwardly direction. These means in the present instance consist of a pair of semi-cylindrical collars w'which lie in a groove 3 in the anvil block q and are held against lateral movement by a coil spring- 2 which snugly engages the periphery of said collars w to hold them in the groove I Y 'Means are provided for restoring the anvil block 9 to an intermediate position whenv ever the pressure used for actuating the anvil block is released therefrom. The means employed forthis purpose consist of a pair of rearward collars 2 which may abut a shoulder 3 in the cylinder cap J and are disposed slidably on the rearward end of the anvil block 9. An opposed pair of col lars 4 are similarly disposed about the anvil block forwardly of the collars Q to seat either against a shoulder 5 of the anvil block or a ainst the rearward surface (3 of the baelr cylinder washer H, depending upon the position of the anvil block (1. The collars i3 and 4- are held in assembled position by a compression spring 7 which encircles them and also acts thereagainst for actuating the anvil block 9 whenever the pressure exerted on said anvil block for compressing the spring 7 is released. At the rearward end of the anvil block g is formed a shoulder S which, when the anvil block is drawn forwardly, may engage the collars 2 for compressing the spring 7 A convenient support for the drill steel t is provided in the form of a centering chuck -9 having a fork 10 so located with respect to the punch pin 4; that when the drill steel t is disposed within said fork 10, the hollow portion of the drill steel will lie in substantially the same plane as the longitudinal axis of the punch pin a. The centering ehucl; in this instance is mounted on a rod 1l whereto it is clamped by means of a bolt 12. The rod 11 extends into an aperture 11-} in the cylinder A and is hold both against rotative and longitudinal movement by a pin 14: extending transversely through the cylinder and the rod.

The operation of the device briefly described is as follows: Let it be assumed that at the beginning of the operation, th anvil block 9 is in the intermediate position hereinbefore referred to, that is, the position to which it will be automatically actuated by the spring 7. If then, it be desired to drive the punch pin 8 into the drill steel t, the attendant may strike a blow on the end V of the throttle lever T to oscillate said throt tle lever to the position indicated in Figure l. In this position, the throttle valve will be open and pressure fluid may then flow throughthe ports 0 and (I into the passage c, thence into the rearward end of the reduced portion E of the piston chamber 13 as well as into the rearward end of the enlarged portion D of the piston chamber for actuating the piston forwardly against the collar o of the anvil block, it being of course understood that the pressure of the drill steel t against the punch pin 8 will be sufficient to compress the spring 7 as shown in Figure l and thus move the collar i; into the path of the hammer piston C. At about the time the piston C is delivering its blow against the collar 1) the rearward end of the passage 7c will be uncovered by the piston, thus permitting the flow of pressure fluid through the passage 0 into the front end of the piston chamber B to drive the piston C rearwardly. This reciprocation of the piston C may continue until the restricted portion of the bore in the drill steel I has been satisfactorily opened.

ill)

As is well known, the chilling effect of the punch pin 8 on the heated end of the drill steel a will cause the said drill steel to contract on the punch pin 8 to such an extent that it will cling thereto with sufficient force to enable the anvil block to be pulled to its extreme forward position whenever a pull 011 the drill steel is exerted. As a result the anvil block 9 may be moved forwardly to such a position that the collar 4) will be witlr drawn out of the range of the blows of the hammer piston C and the collars to will then be advanced sulliciently to expose them to the blows of the rearward end. of the piston C. 111 this way the punch pin 8 will be readily withdrawn from the drill. steel thus permitting the spring 7 to expand and force the anvil block 9 to its intermediate position. In this position of the anvil block, the col.- lars 2 will bear against the collar B of the anvil block and the collars 4 against the surface 6 of the back cylinder washer H and the anvil block 9.

After the punching operation has been completed, the attendant may, by dropping the drill steel 6 on the end U of the lever T, tip the lever to its other extreme position, thus closing the throttle valve L and. shutting oil the supply of pressure fluid to the cylinder.

As will be readily seen, the present device forms a complete and compact unit of light weight and simple construction for punching hollow articles. The method of controlling the admission of pressure fluid to the punch is extremely simple as compared with other well known devices of this type. In its extreme positions, the throttle lever T is inclined, thus indicating at all times the exact position of the throttle valve L. This is a desirable feature in devices of this character since it tends to eliminate accidents such as sometimes happen when the supply of air to the device is temporarily cut oil' and shortly afterwards again turned on without closing the throttle valve.

We claim:

1. In a shank and bit punch the combination of a cylinder and piston, an anvil block extending through the piston, a punch pin carried by the anvil block and shoulders on the anvil block adapted to be selectively exposed to the blows of the piston for driving the punch pin into and out of the article intended to be punched, one of said shoulders comprising a, pair of collar members encircling said anvil block and a spring holding said members in position on said block.

2. In a shank and bit punch the combination of a cylinder, a piston having a hollow end, an anvil block extending through the piston, a punch pin carried by the anvil block, shoulders on the anvil block adapted to be selectively exposed to the blows of the piston for driving the punch pin into and .out of an article intended to be punched, one of said shoulders comprising a pair of collar members encircling said anvil block, a spring holding said members in position on said block and a neck on said anvil block adapted to receive the collar members, said piston being adapted to slide over said collar members at its hollowed end.

In testimony whereof we have signed this specification.

ARTHUR E. PETERS. JESSE DITSON.

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