US2789540A - Compound hammer - Google Patents

Description

April 23, 1957 Filed Dec. 2, 1955.

J. !KUPKA ET AL 2,789,540

coMPoUND HAMMER 5 Sheets-Sheet 1 l IJn n 11:::13 U f l l April 23, 1957 J. J. KUPKA ET Al.

COMPOUND HAMMER 5 Sheets-Sheet 2 Filed Dec. 2, 1955 April 23, 1957 J. J. KUPKA ET AL 2,789,549

COMPOUND HAMMER Filed Dec. 2, 1955 5 Sheets-Sheet 3 if @ff IN VEN TORS /l///////////I///xl April ,23, 195'7 J. J. KUPKA ET Ax. 2,789,540

COMPOUND HAMMER Filed Dec. 2, 1955 5 Sheets-Sheet 4 Alg lf- ,M

April 23, 1957 J. J. KUPKA ET AL COMPOUND HAMMER 5 Sheets-Sheet 5 Filed DeG. 2. 1955 COMPGUND HAMMER John I. Kupka, Gladstone, and Carl W. Shattuck, Mountain Lakes, N. J., assignors to McKiernan-Terry Corporation, Harrison, N. I., a corporation of New Jersey Application December 2, 1955, Serial No. 550,718 16 Claims. (Cl. 121-30) The invention herein disclosed relates to steam and air hammers of the pile driver type and in which, usually, the motive fluid is just admitted to lift and then released to drop the ram.

'Operating in this manner such hammers naturally are inetiicient in Vthe use of steam or air and since gravity is the force relied on for the striking blow, the ram and other parts have had to be heavy and bulky.

vWith the hammers rpresently in use, only a relatively short clearance under the shoulder vof the ram is possible so that if a hammer is suddenly lifted off a pile, or pile drops out from under the hammer in soft driving, the shoulder of the ram will hit the bottom he-ad 'and possibly :stretch or break the tie rods or other parts.

The purpose of the present invention is to avoid and overcome the above and other objections or stated in positive terms, to provide a hammer capable of greater drop without loading the tie rods; to effect economy in steamor air consumption and this despite the-considerable increase in clearance volume occasioned `by the lengthcned over-'travel of the ram; to gain improved steam'or air distribution and non-leaking valve operation vand to simplify and improve the construction generally, lincluding makeup Aof the valve units in subfas'sembli'es which may -b'e readily removed and replaced without taking down thehammer. i

These objectives are attained in v`part by trapping -the steam orair in the event of sudden 'dropto 'stop th'e'ra'm before impact of the shoulder; by using the motive `liuid expansibly, "compounding to cushion fat th'eend of the` upstroke and `to accelerate downstroke of the ram :and by cam operated double seal .poppet `valves and 'other features of improvement, as will naturallyfollo'w 'in furthendescriptionrbfthe invention.

The drawings accompanying A`and forming *part o'f'the specification are illustrative of alpresent `fernbodin'xent"of the invention. Structure, lhoweven-may -b`e modilied afnd changed, all within vthe -true intent and Ascopeof the `1invention as hereinafter defined and claimed.

` Figure l in the drawings is a verticalsectional'view lof one of the hammers showing lthe Vram Aup Iolf the anvil far enough for the cam to permit closing of theadmission valve.

IFigure 2 is'an elevation lookingat'the'rig'hthand or ilveiside of thehammer. l

` gui-e3 is an enlarged Avertical"sectionalfview'of lthe admission valve l`taken on "substantially the plane of line 3-3 of Figure 2. A

EFigure il is rabroke'n ho'rizc'nital "'se'ctionalview 'of 'the pilot 'valve as on'substantiallyth'eplane ZofliIieVl-lri of FigureFZ.

Figures and 6 "are broken vertical fsectionalviews of the differential valve onsubstantially the plane of 4line 5 6 nf-:Figure fshowtng-"this mechanism fasfwithiitheframatlropfposil nited States Patent O l 2,789,540 Patented Apr. 23, 19557` 'ice tion and live steam `from the pilot valve forcing the dif# ferential pistons down to close the exhaust valve and open the compounding valve to pass partially expanded steam'to the top of the ram.

Figure 7 is an elevation showing the valve side of the upper cylinder.

Figures 8, 9, 10 and l1 are cross sectional views on substantially the planes of the correspondingly numbered lines in Figure 7.

The hammer shown in Figures 1 and -2 may be considered, for purposes of disclosure, kas a sand drain hammer operated by steam, though well understood the invention may be applied to other purposes and possibly other expansive uids be used.

In these views the cylinder is shown as 'made up of an upper head 15, upper cylinder 16, intermediate head 17, lower cylinder 18 and bottom head 19 secured together by tie `rods 20 and the ram as having a larger upper end portion 21 operating 'as a piston in the upper cylinder and a lower smaller guide portion 22 operating in the lower cylinder, with an intermediate annular shoulder 23 opposed t0 the intermediate vhead 17 and providing with the surrounding upper cylinder wall an annular high pressure expansion chamber 24.

Steam is supplied at 25 to steam chest 26 containing admission valve 27, the latter having a roller 28 engageable by a cam 29 on the lower end of the upper, piston portion of the ram.

"Admission valve 27 closes as piston cam 29 leaves engagement with roller 28 and expansion continues until the top of the piston at approximately three-quarter stroke engages ball 3l) of pilot valve 31, which, supplied with live `ste-am by conduit 32 then opens to pass steam byconduit 33 to the top of the diiferential valve 34 which is thereby actuated to close ott the exhaust valve and open a transfer or compounding valve for passing partially expanded live steam from below to above the piston for cushioning upstroke and for accelerating downstroke of the piston.

On thedownstroke, steam trapped beneath the piston by downward movement of the piston closing admission port 35 permits long overstroke, ysuch as might result from the pile dropping away from the hammer, without abutment shoulder 23 `striking the intermediate head for the-hammer otherwise damaging itself.

The admission valvefis shown in VFigure 3 as made up of a balanced double poppet valvev member Vhaving valve faces `36, 37 engageable `with valve seats 38, 39 carried by a tubular slidingly guided stem 4l) acted on yin closing direction by a `spring 41 and carrying at'the :inner end the carnengaging roller 28.

When this valve is'opened lay-engagement Vof cam 29 with valve roller 28 at `the end of the downstroke of the ram, live-steam will `lee-passed from steam chest 26, up through passages 42 and `out through ports 35, Figurefll), into expansion chamber 24 beneath the upperpiston portion of the ram.

The pilot `valve at the upper end of the cylinder is shown in Figure 4 as comprising a slidingly guided tubular valve stem 43' carrying a poppet valve element 44 closed againstseat 45 by spring 46` and opened by ball3ll at the inner end of the valve `stem engageable by the `top of lthe ram piston.

This view and Figure 3 `show how live steam is led upv from steam chest'26 thro-ugh an embedded or `cast-in `pipe 47^and through'exibleconduit 32to interior of the pilot valve casing-48 andhow when this Vva'lveis opened, live 5,0,fthef`uppe'r of less*diametery than `the 'lowerl and ported at 51 and terminated at 52 to control the two rows of exhaust ports 53, 54 in the upper cylinder 55.

The cylinder 56 containing the lower and larger differential piston 50 is connected by a small bore 57 with one of the live steam passages 42 so that opening of admissionvalve 27 'at the end of the downstroke of the ram will result in passage of live steam beneath the head of differential piston 50, thus to lift that and the connected upper piston 49 to the position shown in Figure 5, opening exhaust ports at 51, 53 and 52, 54 to atmosphere by way of exhaust pipes 58 entered in opposite sides of the differential valve case 59.

Passages 60 extend from the interior of the differential valve case upwardly and terminate in ports 61, Figures 7 and 8, opening into the top of the upper cylinder.

These passages and ports 60 and 6l serve alternately for top cylinder exhaust and compounding purposes.

In the Figure position, with the ram at Contact with the anvil block 62, the latter shown in Figure l., and admission valve open, live steam will be admitted by way of passages 42, S7 beneath the head of lower differential piston Sli, lifting this and connected upper piston 49 to open both sets of exhaust ports 51, 53 and 54, 55 to atmosphere so that on upstroke of the ram, the cylinder above the ram piston will be open to atmosphere through top ports 61 and down passages 60.

When the pilot valve 31 is opened by engagement of the top of the ram piston with the ball 30, live steam delivered down through conduit 33 acting on the upper smaller piston 49 of the differential valve will force this and the connected piston 50 downward from the Figure 5 to the Figure 6 position, pressure on the lower piston being reduced at this time by expansion of the steam completing its work of lifting the ram piston In this downward movement of the differential pistons from the Figure 5 to the Figure 6 position, a cam 63 on the Strut 64 connecting these pistons engages a roller 65 on the end of the hollow sliding stem 66 carrying the compounding or transfer valve.

The latter is shown as a balanced double poppet valve having spaced annular valve faces 67, 68 engageable with valve seats 69, 70 to govern flow between relief ports 71,A

Figures 7 and 9, in the side of the upper cylinder and space 72 within the differential valve case which is in communication with the lower ends of the transfer and upper cylinder exhaust passages 60.

When, therefore, the ' double transfer valve 67, 68 is opened as a result of reduced pressure on the lower piston and increased pressure on the upper piston of the differential valve, as shown in Figure 6, partially expanded steam lifting the ram piston will be released past valve seats 69, 70 intoupright passages 60 opening into the top of the upper cylinder, thus to cushion the` top stroke of the ram and lapply remaining energy of the partially expanded steam to driving the ram downward.

The upper end of the upper cylinder is thus utilized as a low pressure cylinder to extract the last bit of energy from the steam and to drive the ram downward with positive force.

In this downward movement of the ram, steam beneath the ram piston is being by-passed into the upper end of the cylinder over the top of the piston, as indicated in the Figure 6 position, and then as the ram approaches the bottom of its stroke and admission valve 27 is opened, pressure of live steam through passage 57 lifts the differential valve pistons, as in Figure 5, to open exhaust ports 51, 53 and 54, 55, releasing the exhaust steam to atmosphere through discharge pipes 58.

Movement of the dierential valve pistons is cushioned, in the illustration, by resilient buffer pads and plates 72, 73 and 74,75 at the ends of the upper and lower cylinders 55 and 56 with said plates disposed to be stru-ck by these pistons.

The plate 73 for the upper piston serves a further pup pose in the illustration, acting as a valve element pressed by the cushioning pad 72 into engagement with an annular valve seat ridge 76 on the upper end of cylinder 55 so as to exhaust resi-dual steam left in live steam supply conduit 33 from the pilot valve. An annular passage 77 surrounding the valve seat 76 opens to a discharge nipple 7S. Figures l and 2, set in the upper end of the differential valve case, thus to relieve any steam pressure on the upper differential piston on return of the differential pistons to the upper position, Figure 5. This enables pressure on the lower differential piston to hold these pis-l tons in the upper position, Figure 5, as this pressure reduces through expansion of the steam in lifting the ram piston.

Operation With steam supplied at 25, Figure 1, and the ram at the bottom of its stroke with cam 29 in engagement with y roll 28, admission valve 27, Figure 3, will be opened to pass live steam up'through passage 42 and ports 35 into the expansion chamber 24 in the mrain cylinder beneath the upper piston portion 21 of the ram.

As cam 29 leaves roll 28, the admission valve will close with the ram continuing its upward movement under expansive force of the steam.

At approximately three-quarter top stroke, the upper end of the ram piston by engagement with ball 30 will open the pilot valve 31, Figure 4, which will then pass v live steam from conduit 32 down through conduit 33 to the top of the upper smaller differential piston 49 which at that time is in the upper position shown in Figure 5 due to pressure of live steam through passage 57 on the lower larger piston 50.

In the upper position of the connected differential pistons, Figure 5, during upward travel of the rarn piston, the exhaust ports 51, 53 and 52, 54 are open to atmosphere through the side exhaust pipes 58, Figure 2, permitting free escape from the upper end of the cylinder above the nam piston by way of the top ports 61 and down passages 60.

The opening of pilot valve 31 near the top stroke of the ram piston supplies live steam to the top differential piston 49, which shifts from the Figure 5 to the Figure 6 v position, closing exhaust ports 51 and 53 and 52, 54 to check upward travel of the ram and through cam 63 opening the double poppet valve 67, 68, as in Figure 6, to pass partly expanded steam through cylinder ports 71 out and up through space 72 and passages 60 and ports 61 into the top of the main cylinder above the piston for cushioning upstroke and driving the ram downward with accelerated speed.

By thus compounding, the energy of the motive 'fluid is utilized to best advantage and quick fast blows are struck by the ram.` A lighter weight ram may bevused with equal or better` results than have heretofore been' possible with heavier, more expensive and bulkier machines.

The long over-travel of the ram is permitted to avoid injury when the hammer is lifted or the pile may drop from beneath the ram by trapping a cushion of steam beneath the .descending .piston after it has passed the inlet ports 35. This will prevent shoulder 23 on the ram from striking the intermediate head 17, which might effect stretching or breaking of tie rods or injury to other parts. f

At-or approaching the endof downstroke, the cam on the ram opens the admission valve to supply live steam beneath the rarn pistonand to lift differential pistons to the Figure 5 position with exhaust ports open and transfer valve closed, opening the top of the main cylinder to atmosphere for start of the'upstroke of the ram.

The admission valve 27, pilot valve 31 vand differential` valve 34, as shown in Figures 3, 4, 5 and 6, are in the form of separate independent units which can be bolted in place in seats 79, and 81 provided in the side of avea-54e the upper or main cylinder 17. IH ence, these units may be readily renioved and .replaced for inspection, lrepair or other purposes. i p

Figure 3 shows `how theadmission valve requires only a single opening 82 in the cylinder for entry ofthel guide sleeve 83 in which the valve stem 40 operates. p The cage 84 carrying this lguide and the valveseats 38, 39 is shown as secured in the mounting ,seat79 stud bolts85.

The cover 86 for this valve is shown secured in an outer seat 87 by bolts 88 andas carrying a stud forming an abutment for the valve closing spring 41 and carrying a cross pin'90, the s'tem being slottedat 91 to ride over this pin, thus to hold Ythe roller at the inner end of the stem properly lined up with the rarn.

Thefditlerential valve case `59 is shown secured in place by the four bolts 92, Figures l and 2, and Figures 5 and 6 show the valve cage and valve seat carrying member 93 of the transfer valve as a'n integral inner extension of the valve case. l

The closing spring 94 of the transfer valve is shown in Figures 5 and 6 'located` within the hollow stem of that valve in engagement over a positioning and abutment stud 95 on the Wall ofthe cylinder.

The balanced and double ysealing :poppet valve construction assures positive action and avoids leakage at the admission and transfer valves. Also, these parts are readily lubricated.

The machine as a whole is of simple, rugged construction, with relatively few parts and free of complicated Valve action or other parts subject to breakage or likely to get out of order. l

The differential pistons are shown in Figures 5 and 6 as held against turning by a piston guide 96 set in the front of the casing 59 and slidingly engaged by a guide surface 97 on the opposing portion of the strut 64 connecting the two pistons. This piston guide thus keeps the cam 63 in line with the cam roller 65 and takes any side thrust that may be imposed on the cam carrying strut by the valve closing spring 94.

What is claimed is:

1. Compound hammer comprising the combination of differential cylinder and piston form ram operating therein, said cylinder and piston ram having upper and lower end portions of different diameters and provided with opposed annular shoulders joining the portions of different diameters and forming with the walls of the cylinder and ram an annular expansion chamber, an admission valve connected to supply expansive motive uid to said expansion chamber and provided with an actuating member positioned to be engaged and operated by the ram substantially at the end of the downstroke of the ram, a transfer valve connected to transfer partially expanded motive fluid from said expansion chamber to the cylinder above the upper end of the ram and means for actuating said transfer valve on approach of the ram to the upper end of its stroke.

2. The invention according to claim l in which the admission valve is connected with the expansion chamber by a port located to be overrun by the ram on approaching bottom stroke to thereby close and trap sufficient motive fluid in the expansion chamber to prevent striking of the annular ram and cylinder shoulders in the event of the hammer lifting off a pile or a pile dropping from beneath the hammer.

3. The invention according to claim l with said means including differential pistons, actuating connections from said differential pistons to the transfer valve, a pressure supply connection from the admission valve to one of said differential pistons and a pilot valve actuated by the ram and connected to supply motive uid to the other differential piston.

4. The invention according to claim l with said means including differential pistons, actuating connections from said differential pistons to the transfer valve, a pressure supply connection from the admission valve to one of 'd said `differential pistons, a pilot valveK actuated by the ram 'and-connectedto supply motive fluid tothe other differential piston'and exhaust valve means actuated by said differential pistons. l l

f5. The linvent-ion according `to claim l with exhaust valve mechanism connected with the upper end of the top of the cylinder and'having vconnections for actuating.

the'saie by motive uid derived from the hammer.

7. The invention according to claim 1 with said means including connected opposed differential pistons controlling exhaust ports connected to release products from the top of the cylinder and having connections for actuating thesame by motive fluid derived from the hammer, in-` cluding a passage extendingfrom the admission valve for atating'one differential piston and a pilot valve actuated on the upstroke of the ram and arranged to deliver motive fluid to the other differential piston.

8. The invention according to claim l in which said admission valve yand transfer valve are each of balanced double seal poppet valve construction.

9. The invention according to claim l in which said Iadmission valve is in the form of a single unit independently attachable and detachable in respect to the cylinder and the transfer valve with the means for actuating the same is in the form of a single unit attachable and detachable in respect to the cylinder independently of other parts.

l0. The invention according to claim l in which said admission valve includes a valve stem with 'a rolling element on the inner end of the same within the cylinder land the ram has a cam shoulder for operating engagement with said rolling element.

ll. The invention according to claim l in which said means includes a pilot valve having an actuating element projecting within the cylinder for engagement by the ram, differential pistons for shifting the transfer valve, motive fluid connections to and from said pilot valve to one of the differential pistons and a motive fluid connection from the admission valve to the other differential pist-on.

12. The invention according to claim l in which said means includes a pil-ot valve having an actuating element projecting within the cylinder for engagement by the ram, differential pistons for shifting the transfer valve, motive fluid connections to and from said pilot valve to one of the differential pistons, a motive fluid connection from the admission valve to the other differential piston and cushioning means for said differential pistons including a plate valve for the piston supplied from the pilot valve connected and arranged to release pressure on said piston when the pilot valve is closed.

13. A hammer as herein disclosed and comprising a differential cylinder having a larger upper end and a smaller lower end connected by an annular shoulder, a corresponding diameter ram operating in said cylinder and having an annular shoulder opposed to the cylinder shoulder and cooperating therewith and with the surrounding cylinder wall to form an annular expansion chamber, said cylinder having an admission port at the upper end of said expansion chamber and positioned to be closed by the ram to trap motive fluid which will cushion downstroke of the ram and prevent engagement of the ram and cylinder shoulders, an admission valve connected with said admission port and having an actuating element projecting within the cylinder, the ram hav ing a cam engageable with said actuating element substantially at the end of the downstroke of the' ram, a compounding connection extending from a point above vsaid admission port in the cylinder upwardly intothe top of the cylinder above the ram and includinga transfer valve, an exhaust valve at the lower end of said passage and means operated on the upstroke of the ram for closing said exhaust valve and opening said transfer valve and operable substantially at the end of the downstroke of the ram for closing said transfer valve and opening said exhaust valve.

14. A hammer as herein disclosedand comprising a differential cylinder having a larger upper end and a smaller lower end connected by an annular shoulder, corresponding to a diameter ram operating in said cylinder and h-aving an annular shoulder opposed to the cylinder' shoulder and cooperating therewith and with the surrounding cylinder wall to form an annular expansion chamber, vsaidvcylinder having an admission port at the upper end of said expansion chamber and positioned to be closed by the ram t-o tr-ap motive fluid which will 2U ing a cam engageable with said actuating element sub- -stantially at the end of the downstroke of the rarn, a compounding connection extending from a point above said admission port in the cylinder upwardly into the top of the cylinder above the ram and including a transfer valve, an exhaust valve at the lower end of said passage and means operated on the upstroke of the ram for closing said exhaust valve and opening said transfer valve and operable substantially at the end of the downstroke of the ram for closing said transfer v-alve and opening said exhaust valve and including opposed differential pistons connected to actuate said exhaust valve and having means for actuating s aid transfer valve -and separately controlled motive uid connectionsl to said differential pistons.

No references cited.

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