US1072358A

US1072358A - Fluid-pressure-driven tool.

Info

Publication number: US1072358A
Application number: US28912705A
Authority: US
Inventors: Alexander Palmros
Original assignee: PNEUMELECTRIC MACHINE Co
Current assignee: PNEUMELECTRIC MACHINE Co
Priority date: 1905-11-25
Filing date: 1905-11-25
Publication date: 1913-09-02
Anticipated expiration: 1930-09-02

Description

v A. PALMROS. FLUID PRESSURE DRIVBN TooL.

APPLICATION FXLIID NOV. 25, 1905.

1,072,358, Patented Sept. 2, 1913.

4 SHEETS-SHEET 1.

A. PALMROS.

FLUID PRESSURE DRIVEN TOpOL. APPLICATION FILED Nov. z5, 1905.

1,072,358. Patented Sept. 2, 1913.

4 SHEETS-SHEET 2.

` A. PALMRos. t FLUID PRESSURE DRIVEN TDOL.

APPLICATION FILED NOV. 25, 1905. 1,072,358, Patented Sept. 2, 1913.

4 SHEETS-SHEET 3.

IIIIII Il A. PALMROS. FLUID PRESSURE DMVBN Toot. APPLIOATION FILED NOV. 25, 1905.

Patented Sept. 2, 1913.

4 SHEETS-SHBET 4.

N/ENTOR @my WJTNESSES:

lomeys UNTER@ STATES PATENT @Fbllltllit ALEXANDER PALMROS, OF SYRACUSE, NEW YORK, ASSIGNOR TO THE PNEUMELEC- TRIO MACHINE COMPANY, OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK.

FLUID-PRESSURE-DRIVEN TOOL.

Specification of Letters Patent.

Patented Sept. 2, 1913.

To all fro/0m t may concern Be it, known that I, ALEXANDER PALMRos, a citizen of Finland, and resident ot Syraeuse, in the county of Onondaga, State ot New York, have invented certain new and useful improvements in ll`liiicl-Pr'essi'ir'e- Driven Tools, of which the following is a specilication.

rlhis invention relates to lluid pressure driven tools such as mining machines, drills, hammers, riveting machines, ore stamps, dental instruments and the like, and it has for an object to improve that type of fluid pressure driven tools in which the pressure is developed within the tool.

In Letters Patent No. 761,602, granted May 31, 1904, to Carson WV. Damron and myself, a machine .is disclosed wherein a fluid pressure medium, kept supplied by a motor-driven pump, is compressed by the retracting stroke of the tool and permitted to expand and drive the tool forward, in developing the working stroke of the machine; while in an application filed by me on December 13, 1904, (Serial No. 236,738) the above principle is carried forward and applied with greater effect and economy by utilizing the tool piston to maintain the air supply, but only during a portion of its stroke, when the rctarding influence due to pumping is immaterial, and by so combining a special type of prime mover that not only is the pump driven by the motor, but, the too-l piston, being constantly connected, receives the driving Yforce ol the motor in addition to the torce of the pressure medium, and the final impact is measured, not merely by the rate oit forward movement developed by these combined driving forces, but by the product of this velocity by the combined mass of 'the driven member and the constantly connected (moving) driving member acting as a ily wheel. lt is true that the ily wheel ett'ect is not transmitted directly to the drill, but indirectly through piston connection which yields slightly at the instant of tirst impact, to relieve the shock on the machine, but the construction is such that the body of air through which this reinforce of blow is exerted is kept supplied in a dense condition and the eti'eet .is there't'ore peculiarly advantageous for the excavation of many materials, where a prolonged crushing blow is most effective. That is to say, while there is a slight yield at tirst, the blow is followed up by the additional torce before the material attacked can recover from the iirst load imposed upon it and the penetration is greater' than results from a construction where the irst shock is transmitted to and tends to arrest the entire train of driving parts.

In my present application, I still maintain the features oit having the tool tree to move forward with the suddenness due to the expansion oi the air; o't having each compression stroke start with a fresh charge oi' air, oit adding the driving :torce ol the motor to the expansion ot the air in developing the speed ot' the tool; ot building up or adding to the work stored in the tool to be used up at the time ott impact; and following up the tool piston by the driving member to insure a full length stroke. But in the present case the driving member is a second piston constantly connected to the armature of the electric motor, retracting the first piston by suction or an equivalent means, compressing a charge of driving air by its retracting stroke, releasing the charge ol air thus compressed, directly against the driven tool-piston, continuing` the retracting stroke, after the charge ot compressed air has been thus released in order to add the driving motors torce (acting through the body ot air) to the expansive iloree, in the 'forward stroke, and raise the ell'ectiveness ot' the compressed charge, reversing the driving piston and following up the driven piston and thus insuring l'ull stroke ot the latter and completing the work of the tool and sucking in a new charge behind the driving piston preparatory to repeating the cycle of movements. ln other words, for accomplishingl the results set forth above, I now provide a pair ot suitably housed pistons, one of which is connected to the tool carrying member, and the other to a driving motor and connection between the pistons, whereby one piston may impart movement to the other during both the retracting and the percussion strokes of the tool, together with means lor compressing a fluid on the retracting stroke oi the tool and utilizing said compressed fluid expansively, to impart movement to the tool during the percussion stroke of the latter, Vduring which time t-he driven piston is also acted on by the driving piston, through the intermediate column of air. This intermediate column of air, being under compression, continues to transmit the driving influence of the one piston to the other, notwithstanding the acceleration of the driven piston relatively to the driving piston. The body of air through whichV the one piston reinforces the percussion stroke of the other is, in the embodiment herein disclosed, the same body of air that is compressed by the retracting stroke and acts upon the tool pist-on expansively.

@ther and further objects will appear in the following description and will be `more particularly pointed out in the appended claims. Y

In the drawings: Figure 1 is a vertical section of one embodiment of my invention; Fig. 2 is a horizontal sect-ion through the reducing gear connecting the motor with the driving piston; Fig. 3 is a detail' section of the cylinder and its pistons, of another einbodiment of vmy invention, showing mechanical means Ain addition to the vacuum producing means for holding the pistons together during their retraction; and automatically releasing the pistons at the end of such retraction; F ig. 4 is a view of an embodiment similar to Fig. V3 showing fiuid operated means for releasing the mechanical retracting means; Fig. 5 is another embodiment in which the vacuum retraction is assisted by an electro-magnet; Fig. 6 is still another embodiment in which the retraction is assisted by fluid pressure; and Fig. 7 is a side elevation of a mining machine employing the embodiment of my invention shown in Fig. 6; Fig. S is a vertical section of a machine employing the embodiment shown in Fig. 4. Fig. 9 is a section through the valve at right angles to the section shown in Fig. 6.

While I have herein shown and described my invention as embodied in a mining machine, it is to be understood that this is for the purpose of illustration only and that the invention may be embodied in any machine to which it may be applicable.

Referring more particularly to the drawings, 1 indicates a common cylinder, to be hereinafter more fully described in which is mounted a pair of axially alined independently movable pistons 2 and '3. The piston 2, which I shall term the compression driving piston is actuated by an electric or other motor 4 mounted upon the frame of the machine and connected with the pitman 5 of the driving piston preferably by means of a reducing gear.

The reducing gear, which I prefer to use,

comprises a small pinion 6 mounted on the shaft of the motor and meshing with a y large gear 7 mounted upon a spindle 8 transverse to the pitman 5 and extending vertically in the rear of the motor into a bearing 9 on the frame of the machine. Arlhe large gear 7 transmits motion received from the pinion 6, to an eccentric pin 10 and in order to convert the throw of this eccentric pin into a right line movement coincident with the axis of the pitman, said pin carries a crank pinion 117 having a wrist pin 12 which connects with a cross-head 13L on the pitman. The throw of the wrist pin 12, due

to the rotation of the pinion 11, is exactly half the stroke to be imparted to the crosshead 5a, while said pinion 11, by meshing vwith a fixed circular rack 13, receives one rotation about its center for each revolution of its center with the main gear 7 T he fluid driven or working piston 3 actulates the tooll rod 15 which may either be connected to the piston as shown in Fig. l,

f or separate therefrom as is common in other types of fluid pressure driven tools.V lThe common cylinder 1, in which the driving and the driven or stroke pistons work, forms means for storing fluid on the rear or compression face of the driving piston during the pressure developing or retracting stroke, that is, during the simultaneous movement of the pistons or their movement inthe 'same direction, this storage portion or compression space of the cylinder being located at one end thereof. A by-pass 16 extends from a point at or near the end of the cylinder to a point some distance from said end. This by-pass serves as ameans of communication for admitting the fluid compressed during the retracting stroke from the rear or compression face of the piston 2 to the rear or controlling face of t-he stroke or Vworking piston 3 or, in Vother words between the pistons 2 and 3, when the said piston 2 is located between the two ends of the by-pass. The admission of fluid under pressure between the pistons 2 and 3 causes the fluid to exert its expansive force against the piston 3 and' gives to said piston its working or percussion stroke so as to project the tool rod 15. rEhe fluid should be admitted between the pistons prior to the completion of the compression or retracting stroke of the driving piston, the by-pass being, for this purpose, so located as to be uncovered by the driving piston before it reaches the end of the compression or rearward stroke, and the ends of the by-pass being spaced apart to permit the piston 2 to have a movement between them. The object of this is to have the compression or driving piston continue to compress air after the driven piston commences its forward stroke, thus keeping the expanding air to a higher degree of eliiciency than if the air were allowed to expand in the cylinder only at the end of the stroke.

Means is provided to permit the escape ot fluid from the front of the driven piston after driving pressure has been imparted to the rear of said driving piston, this means being in the t'orm of normally open ports 17 which are located a short distance from the opposite end of the common cylinder providing between the ports and this end ot the cylinder, a cushion space 1S. By the time the blow has been struck or the driven piston 3 reaches the cushioned end ot the cylinder, the driving piston starts on its other or forward stroke. To admit a tluid to the storage end of the cylinder during the forward stroke to take the place of the fluid discharged through the by-pass 16, there is provided an inwardly opening valve 19 at said storage end of the cylinder tln'ougl'i which valve the fluid is drawn by the vacuum created by Jthe said forward movement oit the driven piston. The air, between the opposed faces of the pistons, is expelled during such forward movement through an outwardly opening` valve 2O located near the cushion end of the cylinder'. Should the driven piston not go to the Vlimit of its movement, a cushion will be formed between the two pistons, thereby preventing the pistons coming together and breaking any parts ol'l the machine, and this cushion will assist in completing the stroke of the driven piston.

`W hen the motor actuated piston 2 has been moved close to the Stroke piston 3, a connection is established between the pistons to cause the pistons to move simiiltaneously or in the same direction during the retracting stroke of the driving piston 2; said connection permitting independent movement duringv the working` stroke. This is accomplished in l, solely by the formation of a facuum between the pistons, or in other words, the displacing of the fluid in advance ot' the piston 3, due to the inward movement ot the driving piston.

in the embodiment shown in Fig. 3, the oprration of all the parts is the same and in addition thereto a mechanical means is pro- `vided lor making positive the simultaneous movement ol the pistons in the direction ot' retraction. For this purpose, the driven piston. carries a, pair ot' pivotcd springgg-pressed dogs E21 a dapted to engage a slionldered projcction .20 on the driving piston. llVhen the drivimg;` piston reaches Vthe end of its forr'ard stroke, the dogs, riding on the tapered end ot the projection, engage the shoulder on the samc. and during the retracting stroke, the driven piston is Simultaneously drawn in the same direction. To release these dogs at or near the end of the retractingv stroke, a pairof sliding pins 23 is mounted in the driving piston and projects 'from both faces thereof, one end of each pin being adapted to engage a nose 24 on one of the dogs, while the other end of xach pin is adapted to engage the head ol the cylinder. rlhus, as soon as the pins engage the head of the cylinder, the dogs "fl, will be moved on their pivots and out of engagement 'with the shouhleret'l projection 22, and, at the same time, compressed air will be admitted between the opposed 'laces of the alined pistons through by-pass lo.

In the embodiment shown in Fig. 4;, there is provided a lluid operated means for releasing the mechaniiall holdingl means, at the end oil retracling moviancnt, lo permit independent movcment oit the pistons. ln this embodin'ient the shouldered projection 22, together with the spring pressed dogs 23 and their noses fill, is provided, as in Fig. 3. A sliding cup 25, mounted on piston 3 and surrounding the dogs has a central per'loration to permit the `m'ojection Q2 to enter and become engaged by the dogs Q3 at the end oli the inward stroke. The inner edge of this cup engages the noses 24.- on thc dogs, and, when (luid is admitted between the pistons, near the end o'l.1 the retracting stroke, the cup, moving under the inl'luence oi the fluid, moves the dogs on their pivots and the workingI piston 3 is projected.

In the embodiment shown in Fig. 5, the driving piston carries an electro-magnet 2G which is connected hy comluetors 27 with contact plates 9.8 on the pitman Sliding on the contact plates is a pair oil contacts which cause a circuit to be established and a current to pass through the electro-magnet 2G during the retraction oit the dri ving` piston, the magnet thereby acting on the driven piston 3 and assisting the vacuum to cause the driven piston i), to move with the driving piston E2, the circuit being broken at the end ol. said retraction to permit the fluid in the storage portion ot the cylinder 'l to pass between the opposed :Faces of the piston by means o'l' a hy-pass lo thereby projecting the driven piston 3.

.ln the embodiment shown in Figs. G and 7, the retraction ol the driven piston is caused by lluid under compress-ion and during tht` retracting stroke ot the drivingl piston. lhe driven piston 3 is projected in the manner set torth with relation to the other embodiments. rlhe opposite Iend o'lE the cylinder has provided three

ports

30, 3l and 32 which open into a valve housine 33 in which works a sliding;l valve 3ft both 'laces ol which are open to one another thrmigh channel 33t rlhis sliding valve is provided with a channel 35 which, in one position ot the valve, connects the port 3l with a port 36 opening into the atmosplwre and closed hy a strainer 4Q, the valve taking this position at the comniencement of the projection ot the driven piston Atteithe driven piston 3 has been projected and the driving piston 2 starts on its forward movement, the valve 34 shifts so i as to uncover the port 30 and admit the air from between the pistons into the valve housing. Wvhen the oriving piston lhas reached the end of its forward movement and has started to return, the valve is again shifted to connect the port 32 with the valve housing, whereby duid, stored in the valve housing during the forward stroke of the driving piston 2l, is admitted to the outer face of the driven piston 3 to assist vacuum in the retracting of the said piston. These several movements of the valve are produced by a cam 37 on the spindle 8 upon which the large gear 7 is mounted. rlhe cam 37 transmits this motion to the valve by means of' a sliding bar 38 pivoted to one end of a rocking lever 39, the other end of said lever being connected by link 40 with the'pitman 41 of the valve 34.

Having thus described my invention, what l claim and desire to secure by Letters Patent, is:

1. rlhe combination with a suitably housed driving piston, a suitably housed driven piston, means causing the pistons to move in the same direction at one time and means storing an expansible fluid under compression upon the movement of the pistons in the same direction and admitting said com-v pressed fluid to drive the driven piston in the other direction.

2. rhe combination of a suitably housed compression-driving piston and a suitably housed driven piston, means causing the driven piston to be retracted during the compression stroke of the driving piston, and means providing communication between the controlling face of' the driven piston and the compression space of the driving piston, through which, a medium compressed during such retraction, is communicated to the driven piston.

3. ln a percussion implement, a suitably actuated fluid compressing piston, a Huid pressure driven piston, suitable housing for said pistons, said housing provided with means through which the fluid compressing piston displaces the fluid medium in rear of the fluid pressure driven piston and causes the latter to be retracted during the compression stroke of the fluid compressing piston, and also provided with means providing communication between the controlling 'face of the fluid pressure driven piston and the compression space of the fluid compressing piston through which the fluid medium compressed during such retraction, is delivered to the fluid pressure driven piston.

4. The combination with a mot-or actuated driving piston, of a cylinder in which the said piston operates to compress a fluid medium provided with a by-pass at one end permitting the fluid compressed by said piston to pass to the opposite side of said drivintense ing piston when it is between the ends of the by-pass, and a suitably housed independent driven piston moved by the compressed fluid passing from the ley-pass.

5. The combination with suitably housed driving and driven pistons, means providing communication between one face of the driven piston and both the compression and opposite faces of the driving piston through which fluid may flow alternately bet-Ween the driving and the driven piston, the communication between the driven piston and the compression face of the driving piston being controlled by said driving piston, and comprising a by-pass, uncovered by the driving piston on its compression stroke. l

6. ln a percussion implement, a fluid compressing piston, a fluid pressure driven piston, suitable housing for said pistons, and means providing communication between one face of the fluid pressure driven piston .and both -faces of the fluid compressing piston, said means in cooperation with the actio-n of said fluid compressing piston being adapted to exert upon the fluid pressure driven piston. retracting influence and driving pressure alternately, and auxiliary means causing both pistons to move in the same direction during the retract-ing stroke.

7. ln combination with suitably housed driving and driven pistons means providing communication between one face of the driven piston and both the compression and opposite faces of the driving piston through which fluid may flow whereby pressure variations are alternately communicated from the driving to the driven piston, the communication .between the driven piston and the compression face of thel driving piston being controlled by said driving piston, said means of communication between the driven piston and the compression space comprising a by-pass, uncovered by the driving piston on its compressing stroke and located to be uncovered before the driving piston reaches the end of its stroke, so that it continues to supply pressure medium during a port-ion of the forward stroke of the driven piston. f

8. rl`he combination with a motor actuated driving piston, of a cylinder in which said piston works, provided with a by-pass at one end, permit-ting a fluid compressed at said end to pass to the opposite side of said driving piston when it is between the ends of the by-pass, and an independent driven piston moved by the compressed Huid passing through the by-pass, the ends of said bypass being spaced apart sufficiently to permit continuation of the compression stroke of the driving piston and discharge of the fluid medium until after the driven piston commences its opposite stroke.

9. The combination of suitably housed independently movable driving and driven pistons, and means causing simultaneous movement during the retracting` stroke of the driving piston but permitting independent niovemeut of' said pistons, during the opposite stroke of the driving piston.

lO. The combination of suitably housed `iiulependently movable driving and driven pistons, and means cansinosimultaneous movement during the retracting stroke of the driving piston, but permitting independent movement of said pistons, duringthe op posite stroke of the driving piston, and said driving;l piston causing compression of an eX- pansible medium duringn such sii'nultaneous movement and said expansible medium being permitted to exert its expansive force against the driven piston during' the independent movement.

11. The combination of suitably housed drivin and driven pistons, said driving pis ton adapted to develop pressure in a fluid on one stroke, means delivering the fluid to drive the driven piston in the other direction, and means causing the pistons to travel inv the same direction on the pressure developingv stroke.

12. lin combination, a suitably housed drivingv piston compressing an expansible fluid on one stroke, means admitting air to the conmiession side of said piston during its other stroke, a suitably housed independent piston, means causing said independent piston to be retracted on the compressing stroke of the driving piston, and means through which the independent pistou receives its Working stroke from the fluid compressed during such retraction.

13. ln combination, a suitably housed driving piston compressing an expansible fluid, a suitably housed independent piston, means causing said independent piston to be retracted on the compressing stroke of the driving piston, means through which the driven independent piston receives its Working stroke .from the fluid compressed during such retraction, and means permitting the escape of said fluid from the presence oit the driven piston, at'ter imparting the desired d rivinn` pressure thereto.

til. ln a machine, a compressing piston, developinp` pressure in a fluid medium by one stroke of the piston, a Working),l piston, a cylinder common to both of' said pistons, and means for producing a vacuum chamber between the pistons to cause said compression piston to Withdraw the Working piston simultaneously with the compression of the expansible medium.

15. The combination of' alined and suitably housed. driving' and driven pistons, the driving,` piston compressing a fluid on its rear face on one stroke, and means for delivering; said compressed fluid between the opposed faces of the pistons.

16, The combination With alined driving and driven pistons and a housing inclosing said pistons, of means for discharging;` a fluid compressed by the driving piston when the driving piston has reached a certain posilion, to cause the driven piston to be moved in one direction independently of the driving' piston.

17. rlhe eombinat ion with a cylinder, of a pair ol pistons movable therein, a motor for driving one ot the pistons to compress a fluid, and means -l'or delivering said fluid between the pistons.

1S. The combination with a driving piston, of a driven piston alined therewith, and a cylinder' in which both pistons Work, said cylinder being provided with a by-pass and an inwardly seating;- valve near one end.

19. The combination o't alined and suitably housed driving` and driven pistons, the driving piston compressing` fluid on its rear face, on one stroke, means admitting a fluid to the rear face on the other stroke, and means for delivering the compressed fluid between the opposed faces.

ZO. The combination of the independently movable and suitably housed driving and driven pistons, and mechanical means callsing' simultaneous movement duringl the retractiirny stroke of the machine but permitting independent movement of said pistons, during` the Working stroke oitI the machine.

2l. The combination of the independently movable and suitably housed driving and driven pistons, and mechanical means causing' sinmltaneous movement during the retracting stroke oit the driven piston but permitting; independent movement of said pistous, durinpY the working stroke of the driven piston, said means being operated by the fluid pressure `to permit the independent movement.

2Q. 1`he combination with a motor actuated driving piston. ol a cylinder in which the said piston works, provided with a bypass at one end, permitting' a fluid compressed at said end to pass to the opposite side ot said driving;l piston when it is between the ends of thel bypass, and an independent driven piston moved by the compressed fluid passing' from the by-pass and mechanical means causing both pistons to move together in one direction.

23. The combination with a pair of' alined and suitably housed pistons, of a motor driving one of the pistons to develop a fluid pressure on one stroke of said piston, means delivering said fluid pressure to drive the other piston, and a mechanical means establishing a connection between the pistons on the pressure developingr stroke.

2li. The combination with a pair of alined and suitably housed pistons, o1 a motor driving one of the pistons to develop a fluid pressure on one stroke of the said piston, means delivering said fluid pressure to drive the other piston, a mechanical means establishing a connection between the pistons on the pressure developing stroke, and fluid pressure operated means releasing said inechanical means when the fluid is delivered to operate the iiuid pressure-operated piston.

25. The combination of alined and suitably housed ldriving and driven pistons, mechanical connection between the two pistons causing the pistons to move in the same direction at one time, automatic means for breaking said connection, and means storing an eXpansible fluid upon the movement of the pistons in the same direction and causing said expansible fluid to drive the driven piston in the other direction.

26. The combination with a pair of alined and suitably housed pistons, of a motor driving one of the pistons to develop a fluid pressure on one stroke ot' the said piston, means delivering` said iuid pressure to drive the other piston, dogs carried by one of said pistons to cause them to move together on the pressure developing stroke, and means automatically releasing the dogs to permit the fluid driven pistons to move independently of the motor actuated piston.

27. rihe combination with a compression piston, and a driven piston, of a common cylinder for the pistons embodying means for producing a vacuum chamber between said pistons to cause the compression piston to withdraw the driven piston simultanel ously with compressing` a fluid to drive the driven piston forward.

Q8. The combination with a compression piston and a driven piston, of a common cylinder for the pistons embodying` means :tor producing a vacuum chamberV between said pistons to cause the compression piston to withdraw the driven piston simultaneously with compressing a fluid to drive the driven piston forward, and means whereby fluid medium under pressure is delivered to the pressure driven piston nea-r the end of' the retraction of said pressure driven piston.

29. The combination with a cylinder, of a pair of pistons working in the cylinder, a motor driving one of the pistons and developing a fluid pressure on one stroke of said piston, said cylinder embodying means for admitting fluid between the pistons to drive the driven piston, the cylinder :torming a vacuum chamber between said pistons whereby the pressure developing stroke of the motor-actuated piston will cause a vacuum between the pistons and return the fluid driven piston.

30. The combination with a cylinder, of a pair oi' pistons working in the cylinder, a motor driving` one of the pistons and developing a fiuid pressure on one stroke of said piston, means admitting the compressed fluid between the pistons to drive the other piston, means for displacing the iiuid from between the pistons forming a vacuum, whereby, during the pressurev developing stroke, the motor-actuated piston will retract the fluid driven piston, and means for assisting the vacuum to driven piston. Y

31. The combination with a cylinder, of a pair of pistons working in the cylinder, a motor driving one of the pistons and developing a fluid pressure on one stroke of said piston, means admitting the fluid between the pistons to drive the other piston, means for displacing the fluid from between the pistonstorming a vacuum whereby, during the pressure-developing-stroke the mo- Y tor actuated -piston will retract thef huid driven iston and mechanical means estab-` lishing a connection between the pistons on the pressure developing stroke.

The combination of running motor, a driving piston reciprocally actuated thereby, a cylinder in which said piston compresses a uid medium onA one stroke, a driven piston also working in said cylinder, and retracted during the compression stroke of the motor actuated piston,

means communicating the pressureV medium to the driven piston for projecting the lat-f ter, and means permitting the escape of such pressure medium after imparting the desired work to the driven piston; the motoractuated driving piston following the projection of the driven piston, driving out the pressure medium from between the pistons and establishing retracting relation between the pistons.

33. The combination with a pair 'of pistons,'a motor driving one of the pistons, a cylinder in which the pistons work, formed to store a fluid upon' one stroke of the motor actuatedpiston and to deliver said iiuid between the pistons to drive the other piston in one direction, a valve permitting fluid to enter the cylinder on one side of the motor actuated piston on the other stroke of the said piston, and a valve permitting an eX- haust between the pistons during this latter stroke.

34. The combination with a cylinder, of a pair of pistons movable therein, a motor driving one of the pistons, the cylinder being provided with a by-pass near the end in which the motor driven piston works, the ends of the by-pass being spaced apart to permit the piston to be positioned between them, means for admitting a Huid at the by-V lexpansible fluid on one stroke, a suitably return the fluid a continuously housed driven piston, and means admitting the lluid compressed by the driving piston to the driven piston to drive the latter betere the drivin g piston reaches the end of its compression stroke, and continl'iinpy said compression and admission until the driving' piston reaches the end of its stro ze.

3G. The combination oi a suitably housed driving' piston developing pressure in an expansible ,tlnid on one stroke7 a suitably housed driven piston, and a by-pass having one end located to be uncovered by the driving piston before the latter reaches the end oit' its pressure developing stroke, and the other end located so that the piston continues to compress the fluid after the first mentioned end is uncovered.

37. The combination oit a tool carrying` member, a suitably housed reciprocating piston connected with the tool carrying' member, and imparting` thereto a 3ercussion stroke and a retractingr stroke, a second suitably housed reciprocatiiigpiston, communication between the respective pistons through which the second imparts movement to the Afirst, fthe housing :for the second named piston being provided with a ported passage toward its compression end adapted to be uncovered by one of' said pistons whereby tlnid pressure is developed during' the retracting stroke ot the tirst piston and permitted to act expansively against said first piston on its percussion stroke.

38. The combination ot' a tool carrying men'iber, a suitably housed piston connected with the tool carrying' member and imparting' thereto a percussion stroke and a retractinp; stroke, a second suitably housed piston, 'fluid communication between the said pistons through which one imparts movement to the other, the housing 't'or said pistons enibodying a by-pass adapted to be uncovered by one ot' said pistons whereby Afluid pressure is developed on the retrzmtinnr stroke oi the tirst piston and whereby said luid inessure is exerted expansively against the piston oi" 'the tool carrying' member, on its percussion stroke, and an electric motor driving: the said second pist-on.

39. The combination with a reciprocating^ tool and a pair oiZ suitably housed pistons, one of which is connected to the tool, ot connection between the pistons whereby one imparts movement to the other during' both the retraetine` and the percussion strokes ot the tool, said movement imparting: piston deii'elopinp; fluid pressure on the retraeting stroke of the tool and means iter utilizing said iluid pressure expansively to `impart movement to the tool during' the percussion stroke of the latter, and in addition to the driving' ett'ect o't the second piston.

40. In a percussive tool or machine, the coml'iination oit a tool carrying' member, a suitably housed reciprocating` driven piston connected with the tool carryingi,r member, a suitably housed reciprocating driving piston impartingmovement to the lirst named piston, in the direction ol its percussion stroke and also in the direction oi its retracting' stroke, said drivingsrl piston causing tluid pressure to be developed on the rctracting stroke ot the tool and means whereby said fluid I )ressure is permitted to re-act expansivcly against the driven piston on its percussion stroke; means for displacing the iluid 'from between said pistons to lorm a vacuum, the action ot the driving' piston on the driven piston in the direction oit its percussion stroke being through the medium of the body ot' fluid in which pressure is developed by the retiactingz,` stroke whereby the acceleration ot the driven piston relatively to the driving piston does not remove itirom the iniluence ot the driving` piston.

Lll. .ik percussion implement having a connn'essiug' cyliluler, a piston therein, and an air-inlet communicating with the rear end oit the cylinder and with the cylinder 'forward from its rear end, whereby the air is compressed by a lmckward stroke of the piston betere entering the cylinder in t'ront ot the piston.`

ft2. ln a percussion implement, 'the combination of a compressing-cylinder having an air-inlet port a piston in said cylinder, an air passage communicating with the rear end of the cylinder and with the cylinder forward from its rear end, and an inwardly opening normally closed spring-held valve controlling the air-inlet port tor said cylinder.

ili. ln a iluid-pressure-driven percussion tool, the combination et a suitably housed tluid l'n'essure-driven tool-carrying piston a suitably housed motor-driven llhiid-compressing piston and a by-pass leading from the compression side ot the compressing piston to the tool carrying piston; said compression piston acting as a valve iuu'overing said by-pass after developing' elicient comln'ession in the lluid pressure medium.

dft. l'he combination oit a cylinder, a motor driven piston suitably housed therein and cooperating therewith to cause compression ot' a tluid7 a lluid pressure driven piston also suitably housed in said cylinder and means :t'or delivering the compressed lluid between the pistons to drive the lluid pressure driven piston in one direction.

41:5. rl`he combina tion ot a suitably housed piston, a motor driving' said piston in each direction, a suitably housed fluid pressure driven piston` communication between opposed 't'aces ot the two pistons, the housing having` a closed end 'lor cansino; the motor driven piston to compress a [luid during' one ol its strokes and provided with a, by-passage :For delivering tbe [luid thus eornprt-issed to the space between the pistons whereby it is permitted to act expansively to drive the pressure driven piston in one direction.

46. The combination of a motor driven piston, a fluid pressure driven piston, a suitable housing for both pistons, and a chamber in said housing between the opposed `faces of the said pistons,said housing having a closed end for causing the motor driven piston to compress the fluid on one stroke, and provided with a by-pass for delivering the fluid into the chamber between the opposed faces ci the pistons whereby said fluid is permitted to act expansibly to drive the pressure driven piston in one direction and means whereby theV motor driven piston retracts the pressure driven piston during the compression stroke.

47. The combination with a pair of suitably housed pistons; ot means causing both.

pistons to move in the same direction to- Vgether and means tor delivering a compressed iiuid between the pistons to drive one ot them independently of the other.

48. The combina-tion with a cylinder oontaining driving and driven pistons, ot means causing both pistons to move in the same direction during a retracting stroke and means delivering a compressed fluid between the pistons whereby the driven piston moves independently oi' the driving piston during the percussion stroke.

49. A. percussion implement having a suitably housed compression piston adapted on one face to compress air for a subsequent pulsation of a tool, the housing 'for said pisto-n embodying automatically controlled means for passing' the compressed air to the opposite face of the piston.

50. A percussion implement having a suitably housed compressing piston adapted on one tace to compress air for a subsequent pulsation of a tool, and means controlled by the piston for passing the compressed air to the opposite tace of the piston.

51. The combination of suitably housed driving and driven pistons having opposed faces, the driving piston compressing a tluid on its rear tace on one stroke, and means for delivering said compressed iuid between the opposed faces of the pistons.

rlfhe combination with a cylinder, a pair ot pist-ons movable therein, a motor for driving one of the pistons, of an inlet check valve located in the wall ot said cylinder near the rear end and means for affording communication between the space included by the wall of the cylinder, the rear cylinder iead and the rear tace ot the motor driven piston and the space included by the wall of the cylinder the forward face ot the motor driven piston and the rear tace ot the forward piston.

53. The combination with a substantially air tight cylinder of two pistons in said cylinder, whereby it is divided into a central and two end chambers, and an inlet check valve near one end ot' the cylinder adapted to admit air from the atmosphere.

54. ln a luid pressure-drivenpercussion tool, the combination oit'v a fiuid pressure driven tool-carrying piston, a motor-driven compression piston, a suitable housing 'tor said pistons` comprising a Vby-pass leading from the compression side of the compresspiston to the tool-carrying piston; one of said pistons acting as a valve for covering said by-pass while luid pressure is being developed, and for uncovering said by-pass after efficient compression in the Huid pressure medium has been developed.

55. A percussion tool comprising an aircompressing driving piston, a driven piston, a suitable housing for said pistons, comprising a port communicating between the compressing space of the driving piston, and the pressure-receiving tace or' the driven piston; said port being opened after the driving piston has developed the air compression, whereby the pressure medium acts expansively against the driven piston.

56. A percussion tool comprising an aircompressing driving piston, a driven piston, a suitable housing for said pistons, comprising a passage communicating between the compressing space of the driving piston and the pressure-receiving tace ot the driven piston; said passage being opened by the movement of one oi said pistons, lafter the driving piston has developed compression, whereby the pressure medium acts expansively against Jthe driven piston.

57. A percussion machine comprising a suitable wheeled mounting, and the following instrumentalities combined in a single structure thereon and bodily movable to and `from the work therewith, to wit a pistondriven, reciprocating percussion member, a suitable housingV for said percussion member, a passage in said housing successively releasing compressed charges of tluid pressure-medium and delivering the same into the housing of and against the piston of said percussion member, whereby said pressure medium acts eXpansively to develop the percussion stroke of the percussion member, a compression chamber having a discharge passage controll-ed by said passage, a compressing piston alternately drawing into and compressing in said compression chamber, successive charges ot Fluid pressure medium, and an electric motor driving said compressing piston, and receiving energy from an external source.

58. A percussion machine comprising a suitable portable mounting and the following instrumentalities combined in a single structure thereon and bodily movable therewith, to witz-a piston driven, reciprocating percussion member, a suitable housing for said percussion member, a passage in said housing successively releasing compressed charges of 'fluid pressure-medium and delivering the same into the housing o't and against the piston ot' said percussion member, whereby said medium acts expansively to develop the percussion stroke ol the percussion member, a compression chamber, the discharge from which is controlled by said driving piston, and a suitably aetnated compressing piston alternately drawing` into and compressing in said compression chan'iber, successive charges o'fi tluid pressure medium.

A percussion machine comprising a suitable portable mounting, and the 'following instrumentalitieg combined in a single structure thereon and bodily movable therewith, to witr-a piston-driven, reciprocating percussion member, a suitable housing for said percussion member, a passage in said housing t'or successively releasing compressed charges ot' fluid pressure-medium and del ivering the same into the housing otI and against the piston oit said percussion rlnunbcr, the discharge from which is conexpansive-ly to develop the percussion stroke, olf the percussion member, a compression chamber, the discharge from which is rontrolled by the compressing piston, and a suitably actuated compressing piston alternately drawing into and compressing in said compression chamber, successive charges ot' fluid pressure medium; said passage leading from the compression chamber and having a port discl'iarging into thehousing et the percussion member piston and opened by the compression piston after compression has taken place.

(30. A percussion machine comprising a suitable mounting, and the following instrumentalities combined in a single structure thereon, to wit:-a piston-driven, reciproeating' percussion-member, a suitable housing for said percussion member, a passage in said housing for successively releasing compressed charges ot' Afluid pressure-medium and delivering the same into the housing of and against the piston ot' said percussion member, whereby said pressure medium acts expansivcly to develop the percussion stroke of the percussion member, a compression chamber having its discharge controlled by the compressing means, auxiliary means comprising a valve supplying pressure-medum to said compression chamber, and suitably actuated means compressing in said compression chamber, successive charges ot fluid pressure medium.

6l. A percussion machine comprising a suitable mounting, and the following instrumentalities combined in a single structure thereon, to Witr-a piston-driven, reciprocating percussion-member a suitable housing tor said percussion member, a passage in said housing 'for successively releasing compressed charges oit [luid pressure-merlinm and delivering the same `into the housing' oit and against the piston oit said percussion member, whereby said percussion medium acts exlmnsivcly to develop the percussion stroke ot the percussion men'iber, a compression chamber having its discharge controlled by the compressing means, auxiliary means comprising a valve supplying In'essurc-medium to said compression chamber, and su itably acluated .means compressing in said conipression chamber, successive clmrges oil [luid pressure medium, and controlling said passage. i

(32. A. fluid operated mechanism ot the class described comprising a housing, and independently n'iovable compressing and tooloperating elements arranged in alinement in said housing, said housing ilorming means for contining [luid until highly compressed by said compressing element and having a ported passage adapted to be pei-iodirailly covered and uncm-'ercd by one ot said elements tor comlucting the highly connnesscd (luid to the tool-operating element lo drive the latter on its tl'orwa rd stroke at a speed greater than the correspon(ling movennfnt ot the compressing element.

G8. A tluid-opcratcd device ot the class described comprising a, regularly reciprocable fluid compressing element, a tool operating element reciprocable independently and at di'tl'ercntial speeds relatively to the correspomling movements ol the compressing elcment, and a casing :tor said elements having m ams :tor conducting compressed fluid ilrom the compressing element to the tool operating element at a predetermined poi nt in the stroke oi the compressing element to drive the tool operating element at a speed greater than the regular movement ot the compressing clement, and also ilor producing a partial vacuum between said elen'lents whereby the return stroke oil the tluid col'i'ipressing clement will etl'ect the return stroke ot the tool operating element.

(lfl. A iluid-operatial device ol the class described comprising a cylinder, a reciprocatory tool element. and a. tluid-con'ipressing element both mounted in said cylinder, and means 'tor introducing compressed fluid between the latter element and the tool operating element for driving the latter on its power stroke.

G5. A fluid-operated device of the class described comprising a casing having a cylinder 't'ormcd therein, independently reciprocable tool operating and iluirl-compressing elements mounted in said cylinder, said cylinder and compressing element embodying means lor compressing `fluid at one side ot the compressing element and said cylinder embodying means 'lor introducing said compressed fluid between the opposite side of said compressing element and `the tool operindependently movable therein, the reciprocation of the compressing piston in one direction causing a compression of fluid at one side thereof, the casing being provided with a by-pass for conducting the fluid thus compressed to a space between the opposite side of said compressing piston and the tool op-v erating piston for driving the latter on itsl power stroke When the fluid compressing piston reaches a predetermined position.

67. A machine of the class described comt l tool, the combination of a suitably housed prising a suit-able casing having a cylinder,` tool operating and fluid compressing pistons .independently reciprocable therein, the re ciprocation of the compressing piston in one direction causing a. compression of fluid atl one side thereof, the casing being provided with a by-pass having ports communicating ivith the cylinder at different points in its: length for conducting the compressed fluid to a space between the opposite side of said compressing element and the tool operating; piston.

68. In a pressure driven percussive tool,`

the combination of a drivinO element a tool carrying element, and a cylinder housing said driving element and said housing embodying means for introducing a body of highly coinpressed air between opposed Walls of said elements to drive the tool carrying element upon its Working stroke, and also having a closed end for causing the compression of a fluid to develop the tool driving pressure, upon the movement of the driving element in one direction.

69. In combination With driving and driven pistons, of a cylinder housing inclosing both of said pistons and having means providing communication bet-Ween one face of' the driven piston and both the compression and opposite faces of the driving piston through which fluid may p-ass alternately between the driving andthe driven piston.

70. In a fluid pressure driven percussion pressure driven tool carrying piston, a suitably housed motor driven com-pressing pis-` ton, said housing comprising a by-pass leading from the compression side of the compressing piston to th-e tool carrying piston; one of said pistons acting as a valve for covering said by-pass While pressure is being developed and for uncovering said by-pass after efiicient compression in the fluid pressure medium has been developed.

The foregoing specification signed at Syracuse, N. Y., this 20th day of November, 1905.

ALEXANDER PALMRUS. Iii presence of' tivo Witnesses: Jol-1N E. WOODRUFF, JnnniviiAH DiziscoLL.

Copies Vof this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C.