US2121817A - Punch mechanism - Google Patents

Description

`une 28, 1938. P. H. NAST PUNCH MEcHANIsM Filed.' D80. 3, 1934 T@ E @n 'fl flu" f Y a 3. 5.....

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Patented June 28. 1938 PUNCH MECHANISM `Paul H. Nast, Claremont, N. H., assignor to Sull'- l' van Machineryv Company, a corporationV of Massachusetts firmatari@ neccmbers, 1934, serial Nq. 755,128

275 claims.

This invention relates to. punch mechanisms, and more particularly to improvements in a punch mechanism for reforming,v the bore in a hollow rock drill steel.

In hollow: rock drill steels it is frequently necessary to reform or reopen the drill steel bore after the steelY sharpening or forming-`process has taken place, the sharpening or forming process causing the steel bore to. be partially closed or obstructed; This bore reforming operation is generallyeffected by driving a punch pin into the steel bore to open the latter. It often occurs that the punch pin sticksin the steel borel and, causes some difficulty in the removal of the same. f I

An object of this invention isto provide ane improved punch mechanism for driving a punch pin into the steel bore and4 for releasing arstuck pin from the bore.` Another object is to provide yan improvedpunch mechanism having an iniproved punch pin hammer mechanism and. im.

proved means for feeding thehammer mechae .nism to drive the punch pin into andrelease the. same from the drill Asteel bore. Another object is to provide an improved control means for the fl feeding means and for controlling the'hamrner mechanism.. Y A still further vobject is to. provide an improved control meansfor a punchmechanismv whereby. when the punch -pin hasrbeen driven into the drill steel bore a predetermined distance, the direction oi feed is automatically reversed to effect withdrawal of the kpin from the ,drill steel bore and having associated therewith means for varying the range of feed.. These and other objects and'v advantages of the invention will, howevenfhereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustration one form which the invention may assume -in practice.

' In the drawing,.v .Y

Fig. 1 is a side elevational view of the illus: trative form of the improved punch mechanism.

Fig. 2,v is a view in longitudinal section taken substantially on line 2-2 of Fig. 3.

Fig. 3 is al plan viewA of the punchmechanism shown in Fig. 1. l Y

Fig. 4 is Aa rear end elevational view of the punch mechanism shown in Fig. 1. e

Fig. 5 is a detail sectional view showing va portion of the improved control means. Fig. 6 is a cross sectional view Vtaken substantially. on line 6-6 of Fig. 1, with parts shown in elevation. y

yIn this illustrative construction there is shown a punch .mechanism ,generally designated I Ythe frame 1 and arranged transversely beneath mounted on a suitable support 2 in juxtaposition, to a clamping mechanism generally designated 3.

lThe support 2 and clamping mechanism .3 may constitute elements of a forging machine have ing V*additional bit-sharpening functions; Maine 5 tained in bore re-forming position between the' jaws of the clamping mechanism 3 is shown a usual hollow rock drill steel 4 arranged in lorr-y gitudinal alinement vwith the punch mechanism so that when the punch mechanism is fed for. wardly to driveA its punch pin into the drill steel boreY the bore is re-fformed, and thereafter the lpunch pin is automatically withdrawn from the drill steel. y

Now referring to the improved punch meohaf nism, it will be noted Vthat secured to a vertical plane` face 5,- of the support 21 as Vby screws 6., is aframe 'I having .at horizontal guide bore 8 forslidably receiving ther cylinder 9 of a punch pin hammer mechanism generally designated 1,0. The cylinder of this hammer Vmechanism hasa bore I I containing a reciprocable hammer piston I2y having a striking nose I3 for delivering impact blows to the shank I4 of an elongated punch pin I5'. The collared punch pin shank is supported i within a chuck I6 carried within theV forward end of the hammer motor cylinder, and vis re:- tained therein by a suitable punch pin retainer I] with which the shank collar cooperates. Ar. ranged within a rear head block I8 suitably secured to the rear end of the motor cylinder is a valve box I9 containing a suitable form of fiuid distributing valve mechanism for control# ling the supply of motive fluid to the cylinder 9 toieffect reciprocation of the hammer piston |22, thisvalve mechanism controlling, in a well known manner,l the flowv of pressure fluid from apres sure chamber 2li through suitable ports and pas.- sagesto the opposite ends of the cylinder bore. Reference may be made to Letters Patent No. 1,148,310 for a disclosure of a suitable distribut ing valve arrangement. Y Y' y w Arranged parallel with the yguide here 8' bee' neath the latter and likewise formed in the frame 'I isthe bore 2|.of a horizontal feed cylinder 22. Reciprocable in this feed cylinder is afeed piston 23 having avtubular piston rod 24 extending rear: wardly through the packed rear head 25 vof the feed'cylinder and secured at its rear end at V261cv a clamping nut 21 threaded on the rod,y to adepending projection .28 formed integral with the rear head block I8 of the hammer motor.V

The improved control means for the 'punch mechanism ico.rnprises` a valve. bore 3l! formed'n the feed cylinder bore in a vertical plane midway between the ends of the latter, and mounted in this valve bore is a rotary control valve 3| having secured thereto an operating lever 32. As shown in Fig. 6, the control valve has an internal charnber 33 communicating with a pressure fluid supply chamber 34 in turn communicating with any suitable pressure fluid source. A forward feed passage 35 leads from the valve bore to the rear end of the feed cylinder, while a reverse feed passage 36 leads from the valve bore to the forward."

end of the feed cylinder, and the control valve has suitable radial ports 31 and 3B for selectively connecting the feed passages 35 and 36, respectively, with the valve chamber 33. The feed piston 23 is provided with a valve bore 40 containing a reciprocatory valve 4| of the piston type having at its opposite ends conical end-seating portions 42 and 43 adapted to engage appropriate valve seats at the opposite ends of the valve bore 4|). An axial passage 44 connects the forward end of the valve chamber 40 with the forward end of the feed cylinder bore, while formed in the piston rod 24 is an axial passage 46 for connecting the rear end of the valve bore 40 with a passage 41 communicating with the pressure chamber 20 formed in the rear head block |8 of the hammer motor. Connecting the valve bore 40 with the feed cylinder bore at the rear side of the feed piston is a passage 48, V'while connecting the axial passage 46 with the forward end of the valve bore 4|! is a passage 49. Communication of 48 with the valve bore is interrupted when the valve 4| is in its relative rearward position in the bore, and when the valve is in the forward position, shown in Fig. 2, the mouth of 49 is covered. Secured to the piston valve 4| and extending rearwardly axially through the bore 45 in the piston rod 24, is a slidable rod 55 projecting through a stuffing box 5| carried within the rear end of the feed piston rod 24, as shown in Fig. 5. This valve rod 50, when the parts are in the position shown in Fig. 5, abuts the head 52 of a bolt 53 slidably guided in a bore 54 formed in `a bracket 55. This bracket is of a U shape and is secured, as by bolts 56, to the frame 1. Interposed between the bracket 55 and the bolt head 52 and encircling the bolt is a coiled spring 51 for normally urging the bolt into its foremost position. This spring mounted bolt forms a yieldable abutment for the valve rod 50. Means is provided for limiting the range of forward feeding movement of the punch mechanism and for eecting automatic reversal of the punch mechanism when the punch pin has been driven apredetermined distance into the drill steel bore comprising a control rod El! guided within bores formed in lugs 6|, 6| formed on the projection 23 and frame 1, respectiveyfand this rod is adjustable in a direction longitudinally ofthe punch mechanism and held in adjusted position 'by a set screw 62. The forward Vend of this control rod is bent laterally to provide a projectionv 63 engageable with an rabutment 64 formed on the valve lever 32. Pivotally connected at 65 to the valve lever is a manual operating rod S6 guided within the bore of a lug 61 formed on the frame 1 and having a grasping handle 38. V.The mode of operation of the improved punch mechanism will be clearly apparent from. the description given. When the parts are in the position shown in Fig. 2 with the rock drill steel 4 clamped in operative bore re-forming position between the jaws of the clamping mechanism 3,

and with the valve lever 32 thrown rearwardly, as shown in Fig. l, pressure fluid may flow from the pressure chamber 34 through the valve chamber 33, port 31 and passage 35 to the rear end of the feed cylinder bore at the rear side of the feed piston 23, the pressure fluid acting on the rear pressure area of the feed piston to move the llatter forwardly within its bore. Pressure fluid at the same time flows through'passage 48, through the valve bore 4|] past the rear side of the piston 4|, through the axial passage 46 in the piston rod 24 and passage 41 to the pressure chamber of the hammer mechanism., and as a-result, the hammer piston l2 is rapidly recip- Arocated within its bore to deliver impact blows to the shank of the punch p-in l5. As the feed piston moves forwardly within its bore, the hammer motor is -fed forwardly therewith within the guide bore 8 to drive, with a hammering action, the punch pin l5 into the drill steel bore to reform the latter. When the punch pin has been fed forwardly within the steel bore a predetermined distance, the projection 53 engages they abutment 64 on the valve lever 32, thereby throwing the lever forwardly from the position shown in Fig. 1 to a position wherein the port 38 com- Inunicates with the reverse feed passage 3B. Pressure fluid then flows through this reverse feed passage to the forward end of the feed cylinder borre at the forward side of the feed piston, the pressure fluid acting on the forward pressure area of the feed piston to move the latter rearwardly in its bore, moving therewith the hammer mechanism to withdraw the punch pin from the drill steel bore. The pressure fluid in the forward end of the cylinder bore acts on the forward pressure area of the piston valve 4| to move the latter rearwardly from theA position shown in Fig. 2 to the position wherein the valve seating portion 42 cuts off communication of the axial passage 46 with thefpassage 48, pressure `fluid at that time flowing through passage 49 and passages 46 and 41 to the pressure chamber of the hammer motor. During this withdrawal operation a vibrating action is transmitted to the punch pin through the steel retainer |1 acting on the pin shank collar by vibration set up within the hammer motor by the recoil of the hammer piston due to its sudden reversal in motion. Itwill thus be seen that as the punch pin is withdrawn from the drill steel bore it has imparted thereto a vibrative action which tends to facilitate pin release. Upon rearward movement of the punch mechanism, beforethe feed piston engages the rear cylinder head, the piston valve 4| will have had its rearward movement stopped by engagement of the valve rod 50 with the head of the spring bolt 53, so that the continued rearward movement of the feed piston will result in the relative position of the partsshown in Fig. 2, wherein piston valve 4| has its valve seating portion 43 cutting off communication of the passage 44 with the valve bore 40, thereby interrupting the flow of pressure uid from the forward end of the cylinder bore through passage v44, passage 49, passage 46 and passage 41 to the pressure chamber 20 of the hammer mo-tor. Thus the mechanism will be shut down, with the punch retracted and so held by air pressure. The control valve 3| embodies means for connecting the inactive side of the feed cylinder bore to exhaust. By changing the position of the control rod 60, the time when the projection 63 engages the valve lever abutment 64 may be varied, thereby to vary the range of forward feeding movement of the punch mechanism. The operator" by grasping the handle of the'control rod 66 may swing the valve lever 32ito, move the control valve into any desired position. These and other uses and advantages ofthe improved punch mechanism will be clearly app-arent to those skilled in the art.

While there is in this application specifically described one form which the invention may assumein practice, it will be vunderstood Vthat this form ofthe same is shown for purposes of illustration and that the invention may be modified V and embodied in various other forms without departing from its spirit or the scope of the appended claims. i

What I claim asnew and desireV tov secureby Letters Patent is:

l. Ina punch mechanism, a support having aY Vguide,.reversible means for feeding said hammer mechanism forwardly and rearwardly on its guide to effect movement of a punch pin into and out of a drill steel bore, said feeding means including a feeding element, and means for effecting operation of said hammer mechanism duringboth forward and, reverse feeding movements thereofembodying means cooperating directly with said feeding element o-f said feeding means and by such cooperation controlling said hammer mechanism.

3. In a punch mechanism; a support providing a guide, a hammer mechanism slidable on said guide, reversible means for feeding said hammer mechanism forwardly and rearwardly on its guide to effect movement'of a punch pin into and out of a drill steel bore, said feeding means including a feeding element, means for reffecting operation of said hammer mechanism during both forward and rearward feeding Inove-l ments thereof embodying means cooperatingdirectly with said feeding element of said feeding Ymeans and by such cooperation controlling said J5-hammer mechanism, and means for effecting v automatic reversal of the direction of feed of said hammer mechanism when the` punch pin* has been driven into the drill steel Vbore a pre-l determined distance. Y 4. In a punch mechanism, aksupport having a guide, a hammer' mechanism slidable on said guide,v reversible means for feeding said hammer mechanism forwardly and yrearwardly on its guide while hammering? to drive a punch pin p -intoand effectv its withdrawal-from a drill steel bore, said reversible feeding means including relatively reciprocable feed cylinder and pistonfelements; valve means for selectively supplying pressure fluid to the opposite ends of the feed cyl inder element, and means for effecting operation of said hammer mechanism during both forward and rearward feeding movements thereof embodying means cooperating with the feed piston .element for controlling said hammer mechanism.

5. .In a punch mechanism, a support having a guide, a hammer'me'chanism 'slidable on said guide, reversible means for feeding said hammer mechanism forwardly and rearwardly on its guide to effect movement of a punch pin into and .out of a drill steel bore, said reversible feeding meansy including relatively reciprocable feed cylinder and ypiston elements, valve ,means for selectively supplying pressure fluid tothe opposite ends of thefeed cylinder element, means for effecting operation of said hammermechanism during both forward and g rearward feeding movements thereof embodying means cooperating with thefeed piston element for controlling said hammer mechanism, and means associated with said pressure fluid supply controlling valve means for eecting automatic reversal of said feeding means when the punch pin has been driven into the drill steel bore a predetermined Y distance.

6. In a punch mechanism, a support having la guide, a hammer mechanism slidable on said guide and comprising a pressure fluid actuated hammer motor for delivering impact blows toa punch pin, reversible feeding means for said hammer mechanism for feeding said hammer mechanism forwardly and rearwardly on its guide to effect movement of the punch pin into and out of a drill steel boreisaid feeding kmeans includ-Y ing relatively reciprocable pressure fluid actuated cylinder and piston elements, Vvalve means for controlling the supply of pressure fluid to the Y punch pin, reversiblefeeding means distinct from said guide and spaced from the latter for feed# ing said hammer mechanism forwardly and rearwardly on its guide to effect movementof the punch pin into and out of adrill steel bore, said feeding means including relatively reciprocable pressure fluid actuated cylinder and piston elements, valve means for controlling the supply of cylinder elementyand valve means cooperating opposite ends of the feed cylinder element, V,andv

' hammer'motor for delivering impact blows to a pressure fluid to the opposite endsof thejfeed i5() with the feed piston element -fo-r controllingfthe supply of pressure fluid to said hammer motor, thepressure fluid flowing from the feed cylinder valve means to said hammer motor.V l p 8. In a punch mechanism, a support'having a gui-de, ak hammer mechanism slidable on lsaid guide comprising a pressure fluid actuated hammer motor for percussively actuating a punch pin., reversible means distinct vfrom Vsaid guide and spaced from the latter for feeding saidhammer mechanism forwardly and rearwardly on itsrguide to effect movement of the punch pin into and out of a drill steel bore, said feeding means compris ing relatively reciprocable pressure uid actuated feed cylinder and piston elements.' valve meansV j element under the control 'of said last mentioned from one end of said feed cylinder element'and when sai-d feed piston element is moving in the opposite direction receiving pressure fluid from the opposite end of said feed cylinder element.

9. In a punch mechanism, a support having a guide, a hammer mechanism slidable on said guide comprising a pressure fluid actuated hammer motor for percussively actuating a punch pin, reversible means for feeding said hammer mechanism forwardly and rearwardly on its guide to effect movement of the punch pin into and out of a drill steel bore, said feeding means comprising relatively reciprocable pressure uid actuated feed cylinder and piston elements, valve means for supplying pressure fluid to the opposite ends of said feed cylinder` element, valve means associated with said feed piston element for controlling a supply of pressure fluid from the feed cylinder element to said hammer motor, said hammer motor when said feed piston element is moving in one direction receiving pressure fluid from one end of said feed cylinder element and when said feed piston element is moving in the opposite dlrection receiving pressure fluid from the opposite end of said feed cylinder element, said valve means for controlling the supply of pressure fluid to the hammer motor comprising a valve bore formed in said feed piston element, and a relatively reciprocable piston valve in said valve bore, said piston valve when in one relative position admitting pressure fluid from one end of the feed cylinder element to the hammer motor and when in its opposite relative position admitting pressure fluid from the opposite end of the feed cylinder element to the hammer motor.

10. In a punch mechanism, a pressure fluid actuated hammer motor for percussively actuating a punch pin, reversible pressure fluid actuated feeding means for feeding said hammer motor forwardly and rearwardly while in operation to drive the punch pin into and effect its withdrawal from a drill steel bore comprising a reversible feeding motor arranged wholly in lateral offset relation to sai-d hammer motor and having a motor chamber, means for controlling the supply of pressure fluid to thevmotor chamber of said feeding means, and means for effecting operation of said hammer motor during both forward and rearward feeding movements thereof embodying means for supplying pressure fluid to said hammer motor from the portion of the motor chamber of said fee-ding means within which pressure fluid is acting to provide the feeding force.

11. In a punch mechanism, a pressure fluid actuated hammer motor for percussively actuating a punch pin, reversible pressure fluid actuated feeding means for feeding said hammer motor Iforwardly and rearwardly to effect mcvement of the punch pin into and out of a drill steel bore, said feeding means includiing a feeding motor having a motor chamber, means for controlling the supply of pressure iluid to said feeding means, and means for effecting operation of said hammer motor during both forward and rearward feeding movements thereof embodying means for supplying pressure fluid from the motor chamber of said feeding means to said hammer motor, said operation-effecting means including means for automatically cutting off the supply of pressure iluid to the hammer motor when said feeding means reaches its eXtreme limit of rearward feed.

12. In a punch mechanism, a pressure fluid actuated hammer motor for percussively actuating a punch pin, reversible pressure fluid actuated feeding means for feeding said hammer forwardly and rearwardly to effect movement of the punch pin into and out of a drill steel bore including relatively reciprocable feed cylinder and piston elements in offset relation with respect to said hammer motor, valve means for connecting either end of said feed cylin-der element with a source of pressure fluid supply While the other end thereof is connected to exhaust, and valve means arranged within said feed piston element for controlling the supply of pressure fluid from said feed cylinder element to said hammer motor.

13. In a punch mechanism, a ,pressure fluid actuated hammer motor for percussively actuating a punch pin, reversible pressure fluid actuated feeding means for feeding said hammer forwardly and rearwardly to effect movement of the punch pin into and out of a drill steel bore including relatively reciprocable feed cylinder and piston elements, valve means for connecting either en-d of said feed cylinder element with a source of pressure fluid supply while the other end thereof is connected to exhaust, and valve means arranged within said feed piston element for controlling the supply of pressure fluid from said feed cylinder element to sai-d hammer motor, said last mentioned valve means including means for automatically cutting off the supply of pressure fluid from said feed cylinder element to said hammer motor when said feeding means reaches its eXtreme limit of rearward feed.

14. In a punch mechanism, a pressure fluid actuated hammer motor for percussively actuating a punch pin, reversible pressure fluid actuated feeding means for feeding said hammer forwardly and rearwardly to effect movement of the punch pin into and Vout of a drill steel bore including relatively reciprocable feed cylinder and piston elements in offset relation with respect to said hammer motor, valve means for connecting either end of said feed cylinder element with a source of pressure fluid supply while the other end thereof is connected to exhaust, and valve means arranged within said feed piston element for controlling the supply of pressure fluid from said feed cylinder element to said hammer motor, said last mentioned valve means closing olf the exhaust side of the feed cylinder 'hammer mechanism distinct from said guide for feeding said hammer mechanism forwardly and rearwardly on its guide to effect movement of the punch pin into and out of a drill steel bore, said feedingV means including relatively reciprocable pressure fluid actuated cylinder and piston elements, valve means for controlling the supply of pressure fluid to the opposite ends of the feed cylinder element, and valve means associatedwith the feed piston element for controlling the supply of pressure fluid to said hammer motor, the pressure fluid flowing from the feed cylinder element under the control of said last mentioned valve means to said hammer motor.

16. In a punch mechanism, a support having a guide, a hammer mechanism slidable on said guide comprising a pressure fluid actuated hammer motor for percussively actuating a punch pin, reversible means distinct from' said guide for-feedingV said 'hammer1 mechanism forwa'rdly V'arid rearwardly 'on its guide toeffect movement thepunchpin into and Vvout of a`drillA steel ore; said 'feeding means comprising relatively Y pressure-fluid to the Opposite rends or saidffeec cylinder element, and valve means associated i lwith said feed pistonfelement for controlling a Vie supply-of pressure fluid from the lfeed cylinder 'element-*to said hammer motor, said hammer motor 'when said feed piston element is moving in one direction receiving pressure fluid from-A one end of said feed cylinder element Aand when-said feed piston element is moving in the opposite direction receiving pressurefluid from the Vopposite end of said feedv cylindernelement'.

` 17. In a punch mechanism, a'support h avinga guideway, a pressure Fluid actuated ham-mer motor slidably mounted on said guideway for percussively actuating a punch pin, reversible pressure fluid actuated feeding means distinct from said support guideway for feeding said hammer motor forwardly and rearwardly to effect movement of the punch pin into and ,out of a drill steel bore including relatively reciprocable feed cylinder and piston elements, valve means for Vconnecting either end of said feed cylinder element with a source of pressure fluid supply while the other end thereof is connected to exhaust,

` and valve means-arranged within said Afeedpiston relement for controlling the supply of pressure fluid from said feed cylinder element to said hammer motor. Y

18. In a punch mechanism, a support having a guideway, a pressure fluid actuated hammer motor slidably mounted' on said guideway for percussively actuating a punch pin, reversible pressure'fluid actuated feeding means distinct from said support guideway for feeding said hammer motor forwardly and rearwardly to effect movement of the punch pin into and out of a drill steel bore including relatively reciprocable feed cylinder and piston elements, valve means for connecting either end of said feed cylinder element with a source of pressure fluid supply while the other end thereof is connected to exhaust, and valve means arranged within said feed piston element for controlling the supply of pressure fluid from said freed cylinder element to said hammer motor, said last mentioned valve means closing off the exhaust side of the feed cylinder element from the hammer motor while the live pressure side of the feed'cylinder element is connected to the hammer motor.

Y. 19. In a punching mechanism, a guide, a hammer mechanism slidable on said guide, means for feeding said hammer mechanism forwardly and rearwardly along said guide,` means for automatically reversing the direction offeed when said hammer mechanism has been'fed in one direction a predetermined distance, and associated means for varying the distance of travel of said hammer mechanism. v

20. VIn a punch mechanism,` in combination, a pressure fluid actuated hammer mechanism for percussively actuating a punch pin, a pressure fluid actuated reversible feeding motor arranged in parallel offset relation with the hammerv mechanism for feeding the latter forwardly to drive the punch pin into the work and rearwardly to release the punch pin from the work, said feedinglmotor having a motor chamber containing a movable motor element, means 'for supplying pressure fluid to the motor chamber of s aid feedy operation of motor for feedthe punchlpin into the work Vand rearwardly to f releasegthe punchr pin from thework, said motor having a motor chamber containing a movable motor element, means for,y supplying pressure uid tothe motor chamber of said feeding motor toeffect; operation thereof in either direction; and means for supplying pressure fluid'from the motor chamber of said feedingmotor to,` said hammer mechanism to effect operation of the latter .during either direction of feed, said pres,- sure fluid supply means including a reversing vvalve for supplying pressure fluid tosaid hammer mechanismI from the rearward end ofthe feeding motor and for cutting off communication of the hammer mechanism with the forward end Y of the feeding motor during forward feed and vice versa.

22. In a punch mechanism, in combination, a

pressure fluid actuated hammer mechanism for percussively actuating a punch pin, a pressure fluid actuated reversible feeding motor for feeding the hammer mechanism forwardly to drive the punch pin into the work and rearwardly to release the punch pin from the work, said feeding motor having a motor chamber containing a movable motor element, means for supplying pressure fluid to the motor chamber of said feeding motor to effect operation thereof in either direction, and means for supplying pressure fluid from the motor chamber of said feeding motor to said hammer mechanism to effect the latter during either direction of feed and including a reversing valve for cutting off communication of the hammer mechanism with the forward end of the feeding motor during forward feed and vice versa, said reversing valve controlled at least in part by the pressure of the fluid in the feeding motor.

23. In a punch mechanism, inY combination, a pressure fluid actuated hammer mechanism for percussively actuating'a punch pin, a pressure fluid actuated reversible feeding motorfor feeding the hammer mechanism forwardly to drive the punch pin into the work and rearwardly to ing motor having a motor chamber containing a movable motor element, means for supplyingv pressure fluid to the motor chamber of said feeding motor to effect operation thereof in either direction, means for supplying pressure fluid from the motor chamber of said feeding motor to said hammer mechanism toeffect operation of the latter during either direction ofr feed and in-` cluding a reversing valve means for cutting off communication of the hammer mechanism with the forward end of the feeding motor during forward feed and vice versa, `said reversing valve means controlled at leastin part by the pressure of the fluid in the feeding motor, and mechanical means for positively shifting the connections effected by said valve means as said hammer mechanism assumes a predetermined posupport providing a guideway, a pressure iiuid actuated hammer mechanism mounted on said guideway to move longitudinally therealong for percussively actuating a punch pin, a pressure iluid actuated reversible feeding motor for feeding the hammer mechanism either forwardly or rearwardly along said guideway to eiect movement of the punch pin into or out of the work, a reversing valve for said feeding motor, an abutment, movablewith said hammer mechanism, valve operating means engageable with said abutment for effecting shifting of said valve to reverse the direction of feed when the punch pin has been driven in to the work a predetermined distance, a valve for controlling the supply of pressure fluidV to said hammer mechanism, a stop on said support, and controlling means for said last mentioned valve engageable with said stop for eiecting the cutting off of the flow of pressure fluid to said hammer mechanism when said feeding means assumes a position near the end of its reverse feed.

V25. In a punch'mechanism, in combination, a pressure fluid actuatedhammer mechanism for percussively actuating a punch pin, a pressure uid actuated reversible feeding motor arranged in parallelism with the hammer mechanism for feeding the latter forwardly to drive the punch pin into the work and rearwardly to release the punch pin from the work and comprising a cylinder having a bore containing a reciprocable feed piston having its piston rod connected to the hammer mechanism, means for supplying pressure fluid to said feed cylinder to effect operation of the feed piston in either direction, and means for supplying pressure fluid from said feed cylinder of said feeding motor to said hammer mechanism to effect operation of the latter during either direction of feed including supply passage means formed in said piston rod and communicable with the cylinder bore.

PAUL H. NAST.

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