US1935397A - Pressure actuated punching mechanism - Google Patents

Description

' Nov. 14, 1933. D. w. HART 1,935,397

PRESSURE ACTUATED PUNCHING MECHANISM Filed July 16, 1931 b i UM j a & gg w H15 ATTORNEY.

to the article being punched. I

' refer to similar parts, 7

Patented Nov. 14, 1933 .1.

,PRESSURE A TUATED PUNCHING MECHANISM I -Dudley W. Hart, Phillipsburg, N.-J., assignor to Ingersoll-Band Company, Jersey City, N. .L, a corporation of New Jersey I Application July 16, 1931. Serial'No. 551,165

2-Claims.' (01. 765) This invention relates to punching mechanism, modate a reciprocatory hammer piston Q. The but more particularly to a punching mechanism hammer piston Q may, be of a well known type adapted for pinning out theends of hollow bores. having a head R slidable in the enlarged portion of working implements, such as drill steelswand O of the piston chamber, and a rearward exten-- i the like, and in which the bore or portions there-, sion S which is guided by the reduced portion P oflhave become deformed during prior forging of the piston chamber. operations. 7 In mechanisms employing pistons of the type One object of the invention is to effect such described the extensions may serve as a means pinning out or punching of drill steels through for controlling the distribution of pressure fluid 1 3" the application of indirect blows delivered to, the to the various portions of the piston chamber L punching mechanism and transmitted thereby to for actuating the piston Q. The extension S is the punch .pin. 1 h v p accordingly provided with an annular groove T Another object is to effect the Withdrawal of near the point of union of said extension and the the punch pin from the drill steel by indirect head R to establish communication between the 15'. blows of the hammer piston applied tothe punchrear end of the enlarged portion 0 and a supply ing mechanism, and another object is tov provide passage U leading from the rear end of the rea punching mechanism with, arresting meansduced portion P of the piston chamber to a point; adapted to render alternate blows of. the hammer in said reduced portion slightlyrearwardly of piston ineifective to move the casing with respect the rear end of theenlarged portion 0 of the piston chamber. f Other objects willbe in part obvious and'in The neck or groove T is of such extent that part pointed out hereinafter. whenthepiston Q pp hes its rearmost lim- In the drawing accompanying this specificar, fi g P iQ l in the P s on chamber the groove tion and in which similar reference characters T will establish communication between the pasi, sage U and the rear end of the enlarged portion Figure 1 is a longitudinal sectional elevation O ofthe piston chamber. v e p v, Y of a punching mechanism constructed in accord- The pressure fluid thus distributed may be inance withthe practice'of the invention, and. troduced directlyinto the rear end of the reduced "Figure 2 is a transverse view taken through portion P which. will therefore act'as a constant 301 Figure 1 on the line 22 looking in the direction pressure chamber. and in consequence of which indicated by the arrows. r p p the rear end V of the extension S will be con- ,Referring more particularly to the drawing, stantly exposed-to pressure fluid tending to acthe punching mechanismconstructed in accordtuate the piston Q forwardly.

ance with the practice of the inventionand des The admission of pressurefluid to the front 35 ignatedgenerally by A is mountedupon a-supend of the piston chamber L is likewise controlled port B comprising a bracket C which may be by the extension S. Such pressure fluid'is con- 7 suitably secured to a clamping deviceDvof a well veyedto this end ofv the piston chamber by an known type. The clamping device D may, as is inlet'passage W having its inlet port' X located customary, consist of a base memberE and a intermediate the ends of the reduced portion P 40 clamping die F movable relatively ;-to the base of the piston chamber. Thus arranged the inert i member E and, cooperating therewith toclamp port X will be uncovered by the rear end of thethe work, suchas a drill steel G, securely in poextension S as the piston approaches its forward sition. 1 v v limiting position to admitpressure fiuid into the Qn the outer or free endof the bracket Cis a front end of the enlarged portion 0 of the piston vertical extension H which supports one end of chamber.

guide rods J whereon the; punching mechanism The outlet portY of the inlet passage W pref- A isslidably mounted. The opposite ends of the erably opens into the enlarged portion 0 of the guide rods J may beconvenientlythreadedinto piston chamber at a point located'som'ewhat thebase member E and said guide rods lie inthe rearwardly: of the extreme 'front vend of, said 50 same transverse plane and are parallel with re-; enlarged portion 0 so that, during the operation spect to eachother. V f of the punching mechanism,- the piston willat The punching mechanism A comprises a cylinall/timesbeprevented from striking ,a direct der K bored to form a piston chamberL which blow-against a front head 2 which forms a c10- consists in this instance of anenlarged portion sure for the frontend of thepiston chamber L.v

. O and a rearward r educed portion B to accom- In other words, the supply and inlet passages and the elements whereby they are controlled are so arranged that during both the forward and rearward stroke of the piston the end of the piston chamber toward which the piston Q is moving will be charged with pressure fiuid to assure prompt reversal of the piston before said piston may come into contact with the closures for the ends of the piston chamber, as for instance, the front head Z and a back head I) which seals the rear end of the reduced portion P of the piston chamber.

In accordance with a well understood practice, in apparatus employing pistons of the character described, pressure fluid utilized for actuating the piston is exhausted only from the enlarged portion 0 of the piston chamber. The cylinder K is accordingly provided with an exhaust port 0 located intermediate the ends of the enlarged portion 0 and controlled by the head R of the piston Q.

Preferably the cylinder K is provided with a pair of lugs d located near the extremities of said cylinder and having bores etherein to receive the guide rods J whereby the punching mechanism A is supported with respect to the drill steel G.

The front head Z and the back head I) may be secured fixedly to the cylinder K in any suitable manner, as for instance by side rods 1 arranged on opposite sides of the cylinder K and having nuts g threaded on one end thereof to clamp the p gether. 45

heads securely against the ends of the cylinder K.

In addition to serving as a closure for the front end of the piston chamber L the front head Z also acts as a holder for the working implement, such as a punch pin h. To this end the front head may be provided with a forwardly directed extension 7' having a bore to receive a'shank o of the punch pin h. The'punch pin it may be 40 secured in the extensiona' in any suitable manner, as for instance by a pin p which extends through registering apertures in the shank o and the extension 9' to lock these elements securely to- A retaining element, such as a spring q, may be disposed about the extension 7 to overlie the ends of the pin 10 and thus prevent endwise movement of the said pin.

As will be observed the punching mechanism A is so located with respect to the clamping elements E and F that the punch pin h will lie in the axial plane of the drill steel G and thereforepin h is adapted to open.

' The operation of the apparatus so far described is as follows: With the rear end of the reduced portion P of the piston chamber open to pressure fluid supply, pressure fluid flowing into W said reduced portion will act against the rear 60 end 'V of the extension S to drive the piston Q forwardly. The pressure acting against this endof the piston'will be assisted by pressure fluid previously admitted from the supply passage-U through the annular groove T into the rear end of the enlarged portion 0 of the piston chamber and acting against the rear end of the head B. As the piston Q moves forwardlythe head R will uncover the exhaust port 0 and pressure .70 ffluid will then be exhausted from the rear end of the enlarged portion 0 to the atmosphe r e.

' With the piston in this position the rear end of the extension S will uncover the inlet passage W. Pressure fluid will then be admitted into the e front end of the enlarged portion Oof the piston chamber to reverse the piston. Upon such reversal of the piston a sharp jar or indirect blow will be transmitted to the front head Z which will carry the entire punching mechanism in the direction of the drill steel G and will therefore drive the punch pin h into the passage r of the drill steel.

Admission of pressure fluid into the front end of the piston chamber L may continue throughout a brief portion of the rearward travel of the piston Q after which communication between the inlet passage W and the reduced portion P of the piston chamber will be cut off by the extension S of the piston, so that only the extreme ends of the piston chamber will be exposed to pressure fluid. Inasmuch that the front end of the head R of the piston Q is of larger establish communication between the supply passage U and the rear end of the enlarged portion 0 of the piston chamber to admit pressure fluid thereinto to assist in driving the piston forwardly.

Upon reversal of the piston at the rearmost. limit of its travel a jar or indirect blow will of I course also be imparted to the punching mechanism and which jar in the absence of suitable arresting devices would of coursetend to again withdraw the punch pin from .the drill steel G; In order to prevent such withdrawal of the punch pin the punching mechanism. is provided with suitable arresting means adapted to selectively. render alternate jars of the hammer piston Q' ineffective to disturb or alter the position of the punching mechanism A with respect to the drill steel G. i

' The arresting means selected for illustrative purposes is like that disclosed in U. S. Patent-No. 1,788,034 granted to William A. Smith, Sr., January 6, 1931 in which the arrangement, briefly described, consists of a bracket, herein designated by s, and'shown as forming an integral part of the back head b. V

The bracket s has pivotally mounted thereon a friction shoe't adapted to be pressed'into engagement with the surface of a rod'u by pressure actuated plungers v and w. Therod'u is supand at its other end by the base member E of the clamping device; reciprocable in cylinders 03 and y respectively forming part of the bracket s and to which cylinders the pressure fluid may be supplied by a throttle valve'z arranged, in a casing 2 mounted in this instance upon the bracket 0.

The pressure fluid for actuating the plungers i2 and w maybe carried to their respective cylinders by suitable flexible conduits 3 and 4 for actuatingthe friction shoet from one engaging position to another and for holding said shoe in-such engaging positions.

For a full' description of the arresting device access may be had to the aforesaidfpatent. It may, however, be herein briefly'stated that when--- The plungers o and w are friction ported atone end by the vertical extension 7 against the plunger '0 will swing the friction shoe t forwardly and thus maintain the rearward portion thereof firmly in engagement with the surface of the rod u. I

With the friction shoe t thus disposed the punching mechanism A may only travel in a forwardly direction, that is, in a direction toward the drill steel G upon reversal of the piston Q in the front end of the piston chamber, but, upon reversal of the piston in the rear end of the piston chamber the friction shoe will, by its frictional engagement with the rod u, prevent the punching mechanism from being shifted in a rearwardly direction. It will be apparent, therefore, that only the alternate blows of the piston Q, or, in other words, those jars resulting during the act of reversal of the piston Q in the front end of the piston chamber will be effective to carry the punching mechanism A along the support.

By maintaining the friction shoe t in the position described the punching mechanism will be advanced in the direction of the work and the punchpin h will therefore be rapidly driven into the drill steel. v

After the passage 1 in the drill steel G has been properly shaped or reformed the throttle valve 2 may be reversed to admit pressure fluid into the cylinder 11/. This pressure fluid acting against the plunger 'w will rock the friction shoe rearwardly so that the front portion of said friction shoe will be in engagement with the rod u.

' piston in the rear end of the piston chamber the entire punching mechanism will be carried rearwardly along the support B.

Upon reversal of the piston in the front end of the piston chamber the friction shoe will, by its frictional engagement with the rod u, prevent any movement of the punching mechanism in the direction of the drill steel G. The punch pin it Certain very desirable advantages flow from the present invention. Foremost of these is the complete absence of direct impact of the hammer piston against the elements associated therewith, as for instance, the parts comprising the casing of the punching mechanism, and only indirect blows or cushioned jars will be imparted to such mechanism for driving the punch pin it into and out of the work. This is an extremely desirable feature and one that enables the entire punching mechanism to render service for long periods of time without necessitating replacements due to wear or breakage as has been the case in apparatus of this type heretofore.

I claim:

1. A punching mechanism comprising a casing having a working implement fixedly secured thereto, a member isolated from the working implement and reciprocable in the casing to cause longitudinal vibration thereof, supporting means for the casing, and means associated with the casing and its supporting means selectively to resist vibration in one direction and to yield to vibration in the other direction whereby the casing may be caused to travel along the supporting means to drive the working implement into and withdraw it from the work.

2. A punching mechanism comprising a casing, the punching implement fixedly securedi thereto, an element in the casing isolated from the punching implement and adapted to be reciprocated by pressure fluid to cause vibration of the casing, a support for the casing, and means associated with the casing and its support selectively to respond to vibratory impulses to cause forward and backward movement of the casing and the punching implement lengthwise of the

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