US2429780A - Forging hammer - Google Patents

Description

Oct. 28, 1947. H. TERHUNE FORGING HAMMER (FLUID OPERTED) Filed Sept. 27/ 1944 4 Sheets-Sheet 2 mmyrok. HOW/7E0 vKnew/0N:

I l ll-Hl Oct.'28', 1947. H. TERHUNE 2,429,780

' rename HAMMER (FLUID OPERATED) Filed Sept. 2 7, 1944 4 sheets-sheet s 1 INVENTOR;

Oct. 28, 1947. H. TERHUNE I FORGING HAMMER (FLUID OPERATED) 7 Filed Sept. 27, 1944 4 Sheets-Sheet 4 Ill. .3.

, INVENTOR.

bbvmep 72-12mm:

BY I M WQW Patented Oct. 28 1941 :Howard fl erhune,.r cleveland, IOhio, vassignor of one:half tov The ChampionMachine &.F 01'ging Company, ,Cleveland, Qhio,.-a corporation-=01? .Ohio

Applicationfieptember 27, 19 f4,Serial'-No. 555;977

.4 Claims. 1

.i'llhis invention relates to ..-improvements in forging :hammers, andihas :to do primarily with the operating controls ioroaesteam. hammer. v.In

hammers .of. this type there. are conventionally rtwo'valves, .a control valve for so :directing the live :steam and :the exhaust as to drive the ram 'up :or down. and .a throttle valve tor/determining the rate of flow ;of steam :to'thesteam :chestsurrounding .the control ;valve. .Conventionally: the throttle valve is operat'or actuated exclusively, whilethe controlyalveaiszpartially operator at:-

.tuatedrand partiallyautomatic.

.gIn the conventional construction :the throttle is openzwide :fortthe downxstroke of the ram and inpen .to a very slight degree lonly for the up stroke, inasmuch. as .azvery .islig'ht flow. of :steam :is required for; holdingxthe ram :at :the. top of its stroke or causingjtto swing. upland down near {the top of its stroke. Thisconventional arrange- :ment is :open to certain objections. .Foriexample,

the .ram withits'upper. di'e;may rebound sharply at times .after 'ablow has been struck, and .although the control valve iswdisposed ;-to, admit steam under. the *pistonas soon .as the treadle is "released byithe operator the. approximately closed throttle may not admit enough .steamttolhold the piston up after.v rebound and it mayfall with't'he result of damaging aiorgingthen beingiremoved by the operator or of injuring the operator.

,In accordance :with my invention the, throttle is automatically maintained atleastone quarter open at the beginning :of the up stroke, so that sufficient ,steampis admitted :to the cylinder below the piston to prevent .any .possible dropping. of the, ram, and the :throttle is :gradually moved toward closed position as the ram travels upwardly, its final -.openingbeing comparable to .the constant opening. on "the upstroke in ,such machines ;as'fheretoiore constituted.

One 01" theobjects of the inventiontherefore is the provision of means for causing quick-return .of the ram to .idle position after .ablow has been struck.

Another object is the provision of means for preventing accidental repeat blows.

Other objects and features of novelty will appear as I proceed with the description of that embodiment of the invention which,-for -the-purposes of the present application, I have illustrated 'inthe accompanying drawings, in which Fig. lis :aifront elevational view of a steam hammer embodying the invention;

Fig. 221s azside-view of thesame;

'I'Fig. :3 :is a ,fragmental rview 1 showing 'the .posirtion of :the valve. par-ts .at the instant 'the op- ,erator1streadleis depressed and the ram starts omits-down stroke;

Fig. l is'aisimilarview with the ram at'the end .o'fzitsdown strokean'dthe loperators treadle still depressed;

Fig. 5 is a similar view with the ram down immediately following the release of the trea'dle aby 'Et'he :operator;

fFfig-i'fiis a similarview with the treadle released and the ram swinging or idling in theupper :part of .its path of travel, and

Fig. 7 :is a detail sectional view, on a larger scale, LO'f :a modified form of throttle valve.

ZIn-athe rclrawings thebase 'of a steam hammer is lillustratedaat I10, with frame standards 11 securedltheretn. I2 is a tieplatememb'er carrying --a icylin'der unit 13in the cylinder '13 of which issslidably adisposed a piston 14 atthe top of a -pistonrod li'). JAtthe l'owerendiofitheilatter there iszmounted azram :lfi which-travels between guides -on;-the..-standards 1:1 and carries the -moving die H. .A lower die I8 is mountedin an anvil 19 supported in :base Ill.

The control valve and the throttle valve are both Iformed in :or Icarried by the cylinder 'unit 13, asjis usual in .machinesiof this kind. The control valve comprises a ported sleeve 215 set 211115012, .cylindricalhole in'the cylinder unit. "The lower .end of this hole communicates with an exhaust pipe 21. Ahollow spool valvei22 slides :up and down in sleeve '20, its endspiders being attached to a rod 23 fslidably guided in a cover :.2 4,:andconnected at'its .upperend to a link 25 which is pivotally mounted inthe outer or free end. of an .arm 1-215 that swings about apivot 2'! carried by the cylinder unit. A'passage 28 'connects ports "29in sleeve 20 with the upper end of :cylinder 11'3" and a passage "30 connects ports 31 Ein thesleeve'withthe lower end of the cylin- .der. A'steam chest 3'2 surrounding the sleeve :26 communicates with the interior of the control valve through ports 33.

'The throttle valve comprises a sleeve '35 set into :a cylindrical hole in the outer structure of the-cylinder unit. This sleeve has 3113011336 in communication with steam chest 32 and a port v3i in communication with-a conductor 38 for incoming steam. An oscillatable valve piece 39 within sleeve 35 is movable to control the amount of opening of port Y36 and thereby the 'flow of steam into the chest 32.

On the base of the machine there is mounted the usual trea'dle, comprising a rock shaft All and -foot piece M. From one end of shaft to a crank arm 42 extends forward to a pivotal connection with an upwardly extending link 43 which is pivotally connected at its upper end with an arm 44 mounted to swing about a pivot 45 carried by one of the frame standards. Another link 46 pivotally connected with arm 44, and containing any suitable means for adjusting its length, extends upwardly to a pivotal connection with a lever 4'! that is fulcrumed upon'a pin 48 carried by one of the frame standards H. Upon the opposite end of lever 47 there is mounted a pivot pin 49 upon which is oscillatably supported the hub of a rock lever 59 having two short arms and 52 and a long downwardly extending cam arm 53 of familiar form. The latter cooperates with an inclined cam surface 54 on the ram Hi. The arm 5| of the rock lever is connected by means of a rod 55 with a free end of arm 26, to which is also attached the link 25 previously mentioned. The arm 52 of rock lever 56 is connected by a rod 56 with a crank arm 51 which is operatively fixed to one end of a shaft 59 that carries valve piece 39 of the throttle valve. The effective length of arm 51 may be adjusted by moving its pivotal connection with rod 56, into any one of a series of longitudinally spaced holes, as indicated in Fig. 1. The angular relation of arm 5! with respect to valve piece 39 may also be adjusted by means of a pin and slot connection 59 between the arm 51 and an arm 60 attached to shaft 58.

In Fig. '7 I have illustrated a modified form of throttle valve, by means of which the angular adjustment of the valve relative to port 36 of sleeve 35 may be somewhat more conveniently accomplished. In this case the movable valve element operated by rod 56 is a sleeve 65 having at least two ports 66 and 61. The maximum opening of inlet port 36, 66 is controlled by an inner sleeve 69 which remains fixed under normal conditions. In case it is desired to change the effective opening of the intake port for a given position of the operating sleeve 65, the inner sleeve 63 is rotatably adjusted. This may be accomplished by attaching a shaft to sleeve 68 and causing it to project rearwardly through the valve housing in much the same way that the shaft 58 projects forwardly. Such a rear shaft may have a crank arm connected to a link extending downwardly to any point conveniently within the reach of the operator, such connections being omitted from the drawing for the sake of clearness and simplicity,

Operation-Assuming that the ram I6 is in its upper or idle position and that.the operator desires to have the hammer strike a blow, he then depresses the foot treadle to turn lever 4'! to the position illustrated in Fig. 3. This results in lifting the pivot 49 and with it both of the rods 55 and 56. The upward movement of rod 55 raises control valve 22 to the position shown in Fig. 3 and the upward movement of rod 56 swings throttle valve 39 to a partially open position as also shown in that figure. Steam or other pressure fluid then flows from pipe 38 through port 31 into sleeve 35, out of that sleeve through port 36 into annular steam chest 32, through ports 33 into sleeve 26 and out through ports 29 and passage 29 into the upper end of cylinder [3. The piston I l then travels rapidly downward together with piston rod l5 and ram 16. As the ram descends the cam surface 5 1 permits cam arm 53 to turn clockwise through a small angle, pulling down on rod 55 and pushing up rod 56. The upward movement of rod 56 turns valve piece 39 clockwise, thereby opening port 36 further. The hammer is thus caused to strike a heavy blow. By the time the ram has reached the bottom of its stroke, rod 55 will have pulled valve 22 downward and the two valves will occupy the positions illustrated in Fig. 4.

Now when the blow has been struck the operator naturally releases treadle 49, 4| and the lever 41, which is biased upwardly by spring means not shown, moves to the position of Fig. 5. This causes pivot 49 to descend and with it rods 55 and 56. Spool valve 22 is thereby lowered so as to direct live fluid into the cylinder beneath the piston l4 and to enable fluid above the piston toexhaust through passage 28, ports 29, and through hollow valve 22 to exhaust pipe 2|. At the same time throttle valve 39 is closed to some extent. The adjustments are such however that port 36 remains at least one quarter open; con-= sequently the rise of the piston and the ram is rapid at the start of the up stroke. As the ram rises however, the cam arm 53 swings counterclockwise, drawing the rod 56 down and causing valve 39 to almost close port 36. Before this occurs however, sufiicient steam has been admitted to the cylinder below the piston and to the steam chest 32 to insure fully against any accidental dropping of the ram. As the ram approaches its uppermost position and the arm 53 swings counterclockwise the spool valve 22 is raised to the position of Fig. 6, where port 29 is slightly open to steam within the steam chest while exhaust from the cylinder below the piston is also slightly open. This causes travel of the piston and ram downwardly to approximately the broken line position of Fig. 6, the rocking of the rock lever 56 clockwise about its pivot 49 pulls the spool valve 22 down just far enough to reverse the direction of flow of live steam and exhaust so that the piston and ram again travel upwardly. This is the idling motion which is often referred to in the industry as swinging.

During this swinging of the ram the throttle,

because of the short reciprocations of rod 56, is open slightly less at the top of the ram stroke than at the intermediate positions indicated by broken lines in Fig. 6, but during the swinging action the throttle opening is always relatively small, as it should be in order to conserve steam.

It will be apparent therefore that by the use of my invention the ram is caused to rise rapidly after striking a blow and to be supported in idle position with sufiicient steam to preclude any possibility of accidental movement down to the vicinity of the anvil, but that the throttle is automatically actuated toward closed position as the ram rises, which permits a very small flow of steam at the top of the ram stroke.

Having thus described my invention, I claim:

1. In a fluid operated hammer, a ram, a throttle valve, a control valve, operator actuated means for moving said throttle and control valves to drive the ram up and down, and automatic means responsive to ram movement for causing the throttle valve to move on the up stroke of the ram from a relatively open position to a relatively closed position.

2. In a fluid operated hammer, a ram, a throttle valve, a control valve, operator actuated means tending to open said throttle valve for the down stroke of the ram and to close it for the up stroke, and automatic means responsive to ram movement for modifying the action of the throttle valve to provide relatively wide opening at the start of the up stroke and gradually decreased opening as the ram moves upwardly.

3. In a fluid operated hammer, a ram, a piston connected therewith, a cylinder for said piston, a throttle valve, a control valve, operator actuated means tending to open said throttle Valve for the down stroke of the ram and to close it for the up stroke, and means responsive to the down stroke of the ram for moving the throttle toward open position and the control valve toward the position for feeding live fluid to the cylinder above the piston and responsive to the up stroke of the ram for moving the throttle toward closed position and the control valve toward the position for feeding live fluid to the cylinder below the piston.

4. In a fluid operated hammer, a ram, a throttle valve, a control valve, a rock lever, a pivot therefor, operator actuated means for moving said REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number I Name Date 2,105,074 Eppens Jan. 11, 1938 2,250,449 Eppens July 29, 1941

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