US853201A - Fluid-pressure tool. - Google Patents

Description

PATENTED MAYr 7, 190'?.

VA'-No. 853,201.

E. M. FABER. FLUID PRESSURE TOOL.

APPLICATION FILED JULYZQ, 1905.

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No. 853,201. PATRNTRD MAY 7, 1907.

' R. M., PARRR.

^FLUID PRESSURE TOOL. APPLICATION FILED JULYZQ, 1905.

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FRANK M. FABER, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE PITTS- BURG PNEUMATIC COMPANY, OF CANTON, OHIO, A CORPORATION OF NEW JERSEY.

FLUID-PRESSURE TooL.

Specification of Letters Patent.

Patented May '7, 1907.

Application filed July 29,1905. Serial No. 271,863.

To atl whom it. may concern: l

Be it known that I, FRANK M. FABER, a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, haveinvented a new and useful Improvement in Fluid-Pressure Tools; and I do hereby deelare the following to be a full, clear, and exact description thereof.

My invention relates to pneumatic tools for calking boilers and tanks, forming rivet heads, carving stone, etc. y

One of the objects of my invention is'to provide a device of this character in which the full pressure of the air follows the piston throughout its entire stroke toward the tool, while at the same time to obtain a minimum recoil by causing the piston to come to rest gradually by using the fluid which produces the stroke away from the tool cxpansively so that the pressure on the piston at theinstant that it reverses its motion is practically nil, and-lastly by causing the compressed air to cushion on itself, so to speak, at the instant ol its entrance to the cylinder.

To these ends my invention comprises, generally stated, a suitable body lportieri having a cylindrical chamber therein, a piston in said chamber, a valve chamber and a valve therein controlling ports leading to said cylindrical chamber and to a reservoir into which air is admit-ted simultaneously with its entrance to -the cylinder, whereby the air in said reservoir will act as a cushion to prevent i the too sudden application of pressure to the piston, and the drop in pressure at the induction port is almost entirely compensated for by energy given out by fluid stored `in said reservoir.

` My invention l'urther comprises certain other new and novel features, all of which will be vl'ully hereinafter set l`orth and claimed. v.ltel'erriiig to the accompanyiiig drawings Figure is a longitudinal view ol my iniproved tool; Fig, 2 is a cross sectional view; Figs. 3 and 4 are diagrammatic views which illustrate more readily the. arrangement of ports and which respectively show the valve in positions for directing the lluid pressure to I Produce the forwardv and return strokes ol' 'the piston; and ltig. 5 is a sectional View 'of a modilied t'orm ol' part. ol' my valve mechan- Isin ln the drawings the numeral 2 designates a suitable body which may be ol' any suitable form,'and which is provided with the cylinder 3. Within the cylinder 3 is a piston 4 fitting snugly within said cylinder. At the rear end of the body2 is the valve shell or casing 5 to which is secure-d or formed integral therewith the handle 6 for convenience in manipulating the tool. Within the valve casing 5 is the valve chamber 7 'which conto be understood as limiting myself in any way to such a piston valve, or in fact any particular form of valve. This valve 8 is provided with the rings or collars 9 10 '11 12 and 13, and saidvalve is adapted to move ber 7. Within the body of the valve 8 is Vthe .movable member 15, said plunger being prefiii 5.

gOriices 17 put the valve chamber 7 in communication with-the chamber 14 and the main supply port 18 supplies the air tothe said chamber 7. The pressure of the air in the chamber 14 normally acts to hold the valve in the position indicated in the diagrammatic view Fig. 3, or at the right end of the valve chamber.

to the cylinder 3 and a .port 20 leads from said valve chamber to the reservoir 21. Thls the handle 6, although I do not wish to limit myself in any way to this location, as it may be located in the body of the tool' if desired. The handle 6 is provided with the plug 22 which closes the reservoir 21`and this plug may be screwed up within the reservoir so as to reduce the size of said reservoir if desired.

The port 23 leads from the valve chamber which is at a distance somewhat greater than the length of the piston 4 from the rear end of the cylinder 3. A branch port 23h may also connect the cylinder 3 with the port 23. The )ort 24 leads from the valvev chamber 7 to the front end of cylinder 3 and the port 25 leads from the valve chamber 7 to a point'in the cylinder 3 at a distance from its front end greater than the lcngth'of the piston 4. An exhaust port 2t leads from the valve 'chamber 7 to the atmosphere. A second exhaust port 27 also leads from the valve chamber7 to the atmosphere. A port 2S leads from the 7 and enters the cylinder 3 at the point 23,-

tains a piston valve 8, although I do not wish freely back and forth within the said cham- 7 I chamber 14 within which fits the plunger or erably free from the head 16 of the valve cas- A port 19 leads from the'valve chamber 7 reservoir 21 may be conveniently located in y IOO valve chamber 7 to the space 29 at the'right end of the valve 8 back of the collar 13.

For convenience in operating a throttle valve of any suitable construction should. be located in theport 18 so as to control the supply of air to the'valve chamber 7.

The operation of my improved tool is as follows, and by reference to the diagrammatic views represented in Figs. 3 and 4 its operation will be more readily understood: When the valve S and piston 4 are in position shown in' Fig. 3, fluid pressure admitted through the port 18 enters the chamber 14 through the orifices 17 and holds the plunger 1,5 firmly against the head 16, and forces the valve to the limit of its stroke toward the right, as clearly shown. As the orifices 17 are always in communication with' the feed supply pressure admitted to the chamber 14 the valve is held inthe position shown in Fig.

p 3 until a superior force is introduced'to drive the valve toward the left or into the position shown in Fig. 4. Fluid pressure also siinultaneously enters the cylinder 3 and the reservoir 21 through ports 19 and 20 respectively, the piston 4 now starting on its for ward stroke. By permitting the Huid pressure to enter the reservoir and cylinder in this manner l'gain a two-'fold result: first.

entering the reservoir will act as a cushion to prevent the too sudden application of prespressure at t sys sure to the e induction port 13 which would otherwise be marked as 'the piston reached the completion of its forward stroke?, is almost entirely compensated for by energy. given out by fluid stored in the reservoir. The piston advances then under practicallyinitial pressure until it strikes the tool 30. As 'the piston 4 advances the fluid in front thereof exhausts throughthe ports 24 and 27. Just before reaching the end of its forward stroke the piston passes they port 25 and admits fluid pressure against the opposingI annular surfaces of the rings or collars -`12 and 13. ThelV area of the annular surface of the collar 12 being larger tha-n that of 13 the `introcluction of fluid pressure between them tends to throw the valve toward the left and'by making the areas of these rings or collars such that the difference-in their areasis greater than the cross area of the plunger 15, the tendency exerted by fluid pressure in the chamber 14 is overcome and the valve is thrown to the left.

The resultof moving the valve toward the left is 'as follows: first, the collar 10 closes communication between the induction port 18 vand the reservoir 2l and at or about the same instant the collar 11 closes the port 19; second, the collar 9 passes beyond the port 28 and admi pressure from the reservoir 21 to the space 29 and against the 'end of the valve or the collar 13, thus acting to complete its throw; and third, the collar 11 passes and piston; and second, the drop in 1 'the port 28 opens and admits pressure from lmovement is required.

opens port 23, allowing fluid ressure 'in the cyhnder 3 to exhaust throng ports 23 and 26. At or about the same instant the collar 9 passes the port 24, when the parts will all have assumer the ositions shown in Fig. 4. Fluid pressure in tfie reservoir 21 now passes Athrough the port 20 into the annular space between the collars 9 and 10, thence through the port 24 to the front end of the cylinder.

By admitting pressure from the reservoir to the space 29 a complete throw of the valve under all conditions is insured. Should the port 28 be omitted and the movement of the valve toward the left be entirely dependent on pressure 'admitted through the port 25 the hammer would not start when standing vertically, the forward end down. When in this position the piston drops to the front end` of the cylinder, as shown in Fig. 4. If now the throttle should be opened the valve would be thrown to the 'right by pressure in the cylinder or chamber 14, as before, when pressure would pass through the cylinder and into the space 7 by port 25 starting thel valve toward the left. The moment, however, the port 23 is opened pressure in the cylinder and space 7 yexhausts into the atmosphere through the exhaust 26 and the valve is thrown to the wright by pressurein 14 as already explained. the recoil is greatly modied, since the fluid.

So then under the conditions just described, the valve would not make its complete stroke but would stop entirely or flutter at the point of its throw when exhaust begins. Accordingly l so proportion the parts that the reservoir to the space 29 before the exe haust begins, and as l make thefdiameter of the ring. 13 greater than the diameter of the chamber' 14, the valve willbe thrown completely over under all conditions and be held rigidly in place until the normal reversel The piston having completed its forward stroke, and the valve being inthe position shown in Fig. 4, the action of my hammer continues as follows: 1 Fluid pressure enters the front end of cylinder 3 and acting expansively starts the piston on v its backward or vreturn stroke. i When the piston passes port 23b 'compression begins and gradually brings the piston to rest. When r lthe piston passes entirely beyond 23a the fluid pressure in th e reservoir, the front end of the chamber 3, the space 7a and the end 29 of the vvalve chamber, exhausts through-.ports 23a, 23 and 26. .The fluid pressurein spaces 1 7 a and 29 being now reduced to that of the atmosphere, the fluid pressure in cylinder 14 at once throws the valve'into. theposition shown in Fig. 3, when the cycle of'o'peration's just described is rapidly repeated, n 1 lt is evident th, t by properly proportionin r the volume of the reservoir to volume of cylinder the'fluid pressure used for producingF the return stroke of the piston may .be ex panded down to any pressure desired at'ftlie I' of exhaust As described above the valve is held in the -by= fluid pressure admitted from the reservoir through the passage-Way 28 to the space in the valve chamber It is evident that by lsuitably decreasing the volume of the reservoir the fluid pressure therein may during the return stroke be expanded down to a pressure desired before the piston 4 passes and opens the exhaust port 23a; consequently the relative volumes in the reservoir' andicylinder may be so proportioned that the pressure in the reservoir maybe expanded to a point Where the pressure in the chamber 29 will not be sufficient to nold the valve in the position shown in Fig. 4 against the'constant pressure in the chamber 14. Under these conditions the valve will be thrown into the position shown in Fig. 3 and air admitted through port 19 to produce the forward stroke before the pister` 4, While on its return stroke, passes the exhaust port 23, and consequently the length ofi stroke may be' reduced to any desired vextent by 'a suitable reduction of volume of reservoir.

In Fig. 5 I have shown a niodiiied arrangement of the plunger and chamber to receive the fluid pressure and hold the valve in the position snown in Fig. 3. In this case the chamber4() is formed in the end or head of the valve chamber and the Huid pressure con`- fined therein exerts a continuous tendency to move the valve in a given direction or toward the right, as shown in the accompanying drawings.

Itis obvious that otner methods than those described may be employed for actuating the valve without departing from the spirit of my' invention, and that valves of different types -eoininunicatiifig with said cylinder,

ina-y be employed instead of the one illustrated. Furthern'iore, it is obvious that the location of the reseivoir may be changed and 'that various other changes mav be made in the forni, proportions and' location of parts 'and still come Within the scope of my invention.

What I claim is:

1. In a fluid pressure operated tool, a suity able body portion having a cylinder, a piston, a valve controlling the ports to said cyl-` inder, and a reservoir communicating with said cylinder, and means for operating said valve to alternately connect said reservoir with the fluid pressure supply and with said cylinder. j r

2. In a fluid pressure tool,'a suitable body portion having a cylinder, a piston, -means l'or reciprocating said piston, a reservoir and means for varying the volumeA of said reser voir.

portion having a cylinder, a piston, a reservoir, a valve controlling ports leading to said cylinder and reservoir, and means for ad- 3. In a Huid pressure tool, a suitable body' .y s

moving in both directions, and a branch-port l `i init-ting fluid pressure simultaneously to said cylinder and reservoir.

4. In a fluid pressure tool, a suitable body portion having a cylinder, a piston, a reservoir, a valve controlling ports leading to said cylinder and reservoir, and means for moving said valve by liuid pressure from saideylinder and said reservoir. v

5. In a fluid pressure tool, asuitable body having a cylinder, a piston, a reservoir, a

A valve controlling ports leading to said cylinder and reservoir, and means for moving said valve by fluid ressure from said reservoir.

6. In a Il ui pressure tool, a suitable body portion having a cylinder, a piston', a reservoir, a valve controlling ports leading to said cylinder and reservoir, and a eating with said reservoir an 4carrying fluid .pressure to the valve chamber tooperate said valve.

7. In a fluid pressure tool, a suitable body portion having a cylinder, va piston, a reserort conimunivoir, a valve controlling ports leading to s aid cylinder and reservoir, means lfor carryinor fluid ressure from the forward end of sai cylin er to the valve chamber and from said reservoir to move said valve.

8. In a fluid pressure tool, a suitable body ortion having a cylinder, a piston, means' iston, a handle,` and a or reciprocating said e communicating with reservoir in said han said cylinder. Y

9. In a fluid pressure tool, a suitable body portion having a cylinder, a piston, a valve the movement of said piston,

controlling having a chamber therein' conisaid valve,

niunieating with the fluid (pressure supply, a

plunger in said last name chamber, collars of different areas at vone end of said valve, means for admitting fluid pressure to the space between said collars, the difference in areas of said collars being greater than the area of said chamber, whereby said valve is moved against the pressure Within .saidf chamber.

10. In a fluid pressure tool, a suitable body portion havin a cylinder, a iston therein, a valve control ing ports lea ing to opposite ends of said iston, and a port'conducting fluid from-said cylinder to the valve chamber and thence t the atmosphere and beyond which the entire piston passes when moving in both directions.

11. In a fluid pressure tool, Va suitable body portion having a cylinder, a reciprocating piston therein, a valve chamber, a, valve within said of said piston and a main exhaust passage controlled by said valve, a main exhaust port connecting the passage with the cylinder at a distance from its rear end and beond which the entire piston passes when chamber controlling the motion ISO 12; 'In a fluid pressure tool, a suitable body portion having e cylinder, a pistoue reser- Voir, a valvel for controlling ports leading to said cylinder and reservoir, and means for holding saidyalve in one position b y pressure from said reservoir.

13. In a pneumatic pressure tooLe suitahle body having a cylinder; a 'reciproeating piston Within the cylinder, e reservoir supplying fluid pressure tothe cylinderto force the piston in one direction, and means for increasing or diminishing the volume of the reservoir to produce a corresponding increase or reduction in length of stroke of the piston. 15 In testimony whereof, I the said FRANK M. y FABER have hereunto set my hand,

i l FRANK MFABERQ VVitne-sses A l ROBT. D. TOTTEN, I ROBER'r C. Tonnie.'

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