US3228422A

US3228422A - Control valve mechanism for pneumatically operable devices, especially for driving nails and staples

Info

Publication number: US3228422A
Application number: US229963A
Authority: US
Inventors: Bade Heinz Emil
Original assignee: Joh Friedrich Behrens AG
Current assignee: Joh Friedrich Behrens AG
Priority date: 1961-12-06
Filing date: 1962-10-11
Publication date: 1966-01-11
Anticipated expiration: 1983-01-11
Also published as: DE1478805B2; DE1478805A1

Description

Jan. 11, 1966 H. E. BADE 3,228,422

CONTROL VALVE MECHANISM FOR PNEUMATICALLY OPERABLE DEVICES, ESPECIALLY FOR DRIVING NAILS AND STAPLES Filed Oct. 11, 1962 5 Sheets-Sheet l v j p INVENTOR @3322. Efl'l/ ,BQA/L Jan. 11, 1966 E BADE 3,228,422

CONTROL VALVE MEGHA M FOR PNEUMATICALLY OPERABLE DEV S, ESPECIALLY FOR DRIVING NAILS AND STAPLES Filed 001:. ll, 19 5 Sheets-Sheet 2 IV 17 13 111 m \Z 7 87 O) )(D #1. 9

4 TZ 55 72a 5 I41 721 I0 55 7 51 /f A: 56122 7 Jan. 11, 1966 H. E. BADE 3,228,422 CONTROL VALVE MECHANISM FOR PNEUMATICALLY OPERABLE DEVICES, ESPECIALLY FOR DRIVING NAILS AND STAPLES Fild DCt. 11, 1952 5 Sheets-Sheet 5 INVENTOR United States Patent 3,228,422 CONTROL VALVE MECHAYISM FOR PNEUMAT- ICALLY OPERABLE DEVICES, ESPECIALLY FUR DRIVING NAILS AND STAPLES Heinz Emil Bade, Hamburg-Garstedt, Germany, assignor to Job. Friedrich Behrens, Ahrensburg, Holstein, Germany Filed Oct. 11, 1962, Ser. N 229,963 Claims priority, application Germany, Dec. 6, 1961, B 65,055 9 Claims. (Cl. 137625.6)

The present invention relates to a control valve mechanism for pneumatically operable devices, especially nail driving devices and staplers.

It is an object of this invention to provide a control valve mechanism for apparatuses of the above-mentioned type, which will be simple in construction and reliable and efiicient in operation.

It is another object of this invention to provide a control valve mechanism of the type set forth in the preceding paragraph, which comprises a main valve member and a servo-valve member each of which will be simple in construction.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIGURE 1 illustrates by way of example a longitudinal section through a stapler equipped with a control valve mechanism according to the present invention.

FIGURE 2 illustrates a vertical section through a control valve mechanism according to the present invention on a larger scale than that of FIGURE 1, the valve mechanism of FIGURE 2 being shown in closed position.

FIGURE 2a illustrates the valve mechanism of FIG- URE 2 in opened position.

FIGURE 3 is a section along the line IIIIII of FIG- URE 2.

FIGURE 4 is a section along the line IVIV of FIG- URE 2.

The control valve mechanism according to the present invention which comprises a main valve and a servovalve for controlling the operation of said main valve, is characterized primarily in that said main valve has two different oppositely effective areas rigidly connected to each other and adapted to be subjected to pneumatic pressure for respectively moving said main valve member into opened and closed position.

Referring now to the drawings in detail, and FIG. 1 thereof in particular, FIG. 1 illustrates the control valve mechanism according to the present invention, generally designated V, in connection with a stapler.

The stapler illustrated in FIG. 1 comprises a handle section 1, a main body 1a and a nose section 1c with a staple feeding magazine M. Reciprocably mounted in the main body In is a pneumatically operable piston P with a staple driver D. The handle section 1 includes a large air chamber 2 and a conventional connection as, for instance, nipple N for connection with a suitable supply of air under pressure, for instance air of 5 atmospheres above atmospheric pressure. The air for actuating the piston P in either direction is supplied from the air chamber 2 through a passage 3 while the valve mechanism V interposed between chamber 2 and passage 3 is operable to control air communication between the chamber 2 and the passage 3.

Inasmuch as the main body 1a with the parts pertaining thereto does not form a part of the present invention and may vary in construction in conformity with the respective requirements, no further description of the main body 1a, nose body 1c and magazine M appears to be necessary.

Referring now to the control valve mechanism of the present invention as illustrated in FIG. 2 and 2a, it will be noted therefrom that the lower portion of the handle section 1 is provided with a threaded bore 6 having threaded thereinto a bushing 5. This bushing 5 holds cylindrical sleeve 8 in a bore 10 of the handle section 1 by means of a plate 7 and a plate 9 resting, through the intervention of a gasket G, against a surface 11 of the handle section 1. Reciprocably mounted in a bore 51 bushing 5 is a pin 52 adapted to be actuated by a trigger 120. The trigger 126 is normally held in its FIG. 1 position by means of a spring 119. Pin 52 has a flat portion 54. The upper portion of pin 52 has a neck portion 52a around which pin 52 carries a sealing ring 53 by means of which normally, i.e. in FIG. 2 position of pin 52, the portions 54 is tightly sealed. When pin 52 is lifted, the said portion 54 communicates with the bore 12a of a sleeve 12 which extends through a wide opening 71 of plate 7 while the lower mouth of bore 12a faces a cone 56 forming a part of pin 52. The lower end of sleeve 12 has a head 121 with a cutout or recess 122 through which a recess 5a in bushing 5 communicates with the opening 71. Head 121 rests with radial and axial play on the shoulder 55 of the bushing 5. Normally, i.e. in FIG. 2 position of pin 52, the conical tip 56 of pin 52 is spaced from the lower end of sleeve 12 so that bore 12a of sleeve 12 communicates with the recess 5a in the bushing 5. However, this communication between bore 12a and recess So can be interrupted when the trigger is lifted so as to push a portion of cone 56 into the bore 12a.

Longitudinally displaceably mounted on sleeve 12 is a shank 13 carrying a piston 14 which is displaceable in cylinder 10. Piston 14 carries a sealing ring 141. The profiled shank 13 has a fiat portion which leaves free a passage 111 in plate 11. At its upper end, shank 13 is provided with two sealing rings the upper one 131 of which is adapted tightly to close an opening 21, which latter communicates with chamber 2, whereas the lower ring 132 is adapted tightly to close the passage 111. The upper portion of cylinder sleeve 8 has a reduced outer diameter so that this reduced diameter section together with the housing of the handle section 1 confines an annular chamber 101. This annular chamber 101 communicates with the cylinder chamber 8a through a number of openings 81 and also communicates through said openings 81 with an exhaust passage 4 leading into the atmosphere. Shank 13 and piston 14 form the main valve, and pin 52 forms the servo-valve for the control valve V.

When the device, for instance a stapler, equipped with the control valve mechanism according to the invention is in readiness for carrying out a working strokea stapling operation when considering the staper of FIG. 1 the control valve V occupies the position shown in FIG. 2. In this position, that portion of cylinder chamber 8a which is below the piston 14 communicates with chamber 2 through bore 133 of shank 13, bore 12a of sleeve 12, the lower mouth of bore 120:, chamber 5a, cutout 122 of shank head 121, and bore 71, Consequently, in FIG. 2 position the compressed air pressure prevailing in chamber 2 will thus also prevail in that portion of cylinder chamber 8a which is below piston 14, so that the air pressure in this cylinder chamber portion will hold shank 13 and more specifically its sealing ring 131, in firm engagement with the shoulder 134. This is due to the fact that the effective surface area 142 of valve piston 14 is larger than the uppersurface 13a plus the surface 131a which is exposed to the pressure in chamber 2.

In order now to initiate the working stroke of the device controlled by the valve mechanism according to the inventionthe working stroke of piston P with regard to the stapler of FIG. 1the operator lifts the trigger 120 and immediately thereafter releases the same again. In view of the lifting of said trigger 120, pin 52 is lifted and as shown in FIG. 2a, interrupts communication of the bore 12a with chamber 5a and thereby also with that portion of cylinder 8a which is below the piston 14. The lifting movement of pin 52 also lifts off sealing ring 53 from its adjacent valve seat 5b of bushing 5 so that the air from that portion of cylinder 8a which is below the piston 14 can escape into the atmosphere through

openings

71 and 122 and bore 5a and flat portion 54. The air under pressure now acting upon the upper

shank end face

13a, 131a presses the shank 13 with its piston 14 downwardly into the opening position in which the sealing ring 131 is lifted off from the surface 134 so that communication will now exist between compressed air chamber 2 and the passage 3, while .at the same time the sealing ring 132 closes the opening or passage 111 in plate 9. As a result thereof, compressed air passes through passage 3 and acts upon the stapler piston P so that the latter together with the driver D moves downwardly with regard to FIG. 1 to effect a driving stroke.

When the operator, immediately after he has pulled the trigger 120, releases the same, the trigger will be returned to its FIG. 2 position by a spring (not shown). Compressed air from chamber 2 will then pass again through bore 133 of shank 13, and bore 12a of sleeve 12 into the chamber 5a and from there through

openings

122 and 71 into that portion of cylinder chamber 8a which is below the piston 142. Consequently, as mentioned above, the air pressure acting on the piston surface 142 will move shank 13 into FIG. 2 position so that the air which, during the return stroke of piston P of the stapler, is pushed by said piston into the passage 3, can escape therefrom through opening 111 in plate 9 and bores 81 in sleeve 8 into the exhaust passage 4. The openings 81 will in this instance mufile the sound.

With the control valve mechanism according to the present invention as described above, it will be seen that the main valve opens immediately in response to the initiation of the lifting movement of the trigger 120. The function of said

main valve

13, 131 is thus independent of the trigger stroke and the manner of operation of the trigger by the operator. The said main valve actually responds already to a very small movement of the servovalve 52. The opening 21 which in the open position of the main valve is completely free as to its entire cross section, makes it possible that the compressed air in chamber 2 can immediately pass into passage 3 without encountering any handicap and then pass from passage 3 to the piston P to be actuated. This greatly accelerates the control and driving operation of the device. A further acceleration of the control and driving operation will be obtained if the axis of the valve arrangement were changed so as to coincide with the dot-dash axis x, for instance at an angle of 45 with regard to the driving cylinder in which the piston P is reciprocable, because in this way a flow path would be created which would require a minimum of deviation of the air passing from chamber 2 to passage 3. If also the upper wall or the back of the handle section 1 were given a corresponding inclination, a device would be obtained which would facilitate the handling of the apparatus during the operation thereof.

The entire control valve mechanism consists of relatively few elements and has only one sealing element subjected to wear by movement namely the piston ring 141 for which a so-called O-ring may be selected. The control valve mechanism is therefore relatively non-sensitive against admixtures to the compressed air, such as condensing water or soiling which with ordinary control valve mechanisms may easily bring about leakages. The

wear of ring 141 is reduced already by the fact that the valve shank 13 is guided on sleeve 12 without compressing force because sleeve 12 with its head 121 is journalled between bushing 5 and plate 7 with play in radial as well as in axial direction. The remaining sealing elements namely rings 131, 132 and 56 will stationarily seal and block reliably also when even after a longer time of operation minor deformations occur. The control member may with all parts pertaining thereto be inserted into the handle section 1 from below through bore 6. In this way, the back of the handle section above the control member will remain completely free of protruding parts which could interfere with a smooth and comfortable grasp on the apparatus by hand which other wise could injure the hand of the operator.

As far as the material for the control members according to the invention are concerned, synthetic materials of hard but elastic properties as, for instance, polyurethane may be employed. This will greatly reduce the wear of the apparatus. This would also make part 52 of the O-ring superfluous. Moreover, in this instance, the cone 56 would bring about a particularly effective sealing effect. Similarly, also shank 13 may consist of a synthetic material having pressed thereinto the piston 14 of steel.

It is, of course, to be understood that the present invention is, by no means, limited to the particular construction shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. A control valve mechanism, which comprises: a housing having a cylinder formed therein, said cylinder having compressed air inlet means and exhaust air outlet means and a port to be connected alternately to said inlet and outlet means, plunger means reciprocable in said cylinder for controlling the communication between said port and said inlet and outlet means, said plunger means being provided with two oppositely effective and rigidly interconnected different size areas, the smaller of said areas being in continuous communication with said inlet means and the larger of said areas being adapted to al ternately communicate with the atmosphere and to said inlet means so as to move said plunger means from a first position into a second position and vice versa to respectively establish and interrupt communication between said inlet means and said port while simultaneously respectively interrupting and establishing communication between said port and said outlet means, and a single manually operable valve member associated with said plunger means and normally in a first position to effect communication between said larger area and said inlet means while interrupting communication of said larger area with the atmosphere and also movable into a second position for interrupting communication of said larger area with said inlet means while connecting said larger area to the atmosphere.

2. A control valve mechanism, which comprises: a housing having a cylinder formed therein, said cylinder having compressed air inlet means and exhaust air outlet means and a port for alternate communication with said inlet and outlet means, plunger means reciprocable in said cylinder for controlling the communication between said port and said inlet and outlet means, said plunger means being provided with two oppositely effective and rigidly interconnected different size areas on the opposite ends thereof, the smaller of said areas being in continuous communication with said inlet means and the larger of said areas being adapted to alternately communicate with said outlet means and said inlet means so as to move said plunger means from a first position into a second position and vice versa to respectively establish and interrupt communication between said inlet means and said port while simultaneously respectively interrupting and establishing communication between said port and said outlet means, said plunger means being provided with an axial bore therethrough leading from one of said areas to the other, sleeve means substantially stationary in said housing and extending slidably through said plunger means and open at both ends, and a manually operable valve member movable selectively into one position in which it closes one end of said sleeve means to thereby prevent communication between said larger area and said inlet means while simultaneously establishing communication between said larger area and the atmosphere, said valve member also being movable into a second position in which it opens said one end of said sleeve means to thereby establish communication between said larger area and said inlet means while simultaneously interrupting communication of said larger area with the atmosphere.

3. A control valve mechanism according to claim 2, in which the cylinder formed in the housing comprises chamber means in the housing, a sleeve member in the chamber means and end members in the chamber at opposite ends of said sleeve member, the end of said plunger means forming the larger of said areas being reciprocable in said sleeve member, nut means threaded in the housing and holding said sleeve member and end members in said chamber means and having a bore receiving and guiding said valve member, and passage means formed by said valve member and bore leading to the atmosphere and controlled by said valve member and forming the means for connecting said larger area to the atmosphere.

4. A control valve mechanism according to claim 3, in which said sleeve means is provided with a head at the said one end thereof adjacent said valve member, said head being confined with axial and radial play between said nut means and the said and member adjacent thereto.

5. A control valve mechanism, which comprises: a housing having a cylinder formed therein, said cylinder having compressed air inlet means and exhaust air outlet means and a port for alternate communication with said inlet and outlet means, plunger means reciprocable in said cylinder for controlling the communication between said port and said inlet and outlet means, said plunger means being provided with two oppositely elfective and rigidly interconnected diiferent size areas at its opposite ends, the smaller of said areas being in continuous communication with said inlet means and the larger of said areas being adapted to selectively communicate with the atmosphere and to said inlet means so as to move said plunger means from a first position into a second position and vice versa to respectively establish and interrupt communication between said inlet means and said port while simultaneously respectively interrupting and establishing communication between said port and said outlet means, and a manually operable servo-valve member arranged in substantially axial alignment with said plunger means comprising a substantially stationary sleeve element extending slidably through said plunger means and having one end open to said inlet means and its other end open to said larger area, and a valve member extending through a wall of the housing adjacent said other end of the sleeve element and movable from a first position of spaced relation to said other end of said sleeve element and wherein it permits communication between said larger area and said inlet means into a second position of sealing engagement with said other end of said sleeve element and wherein it interrupts said last mentioned communication, and passage means leading from said larger area to the atmosphere and closed by said valve member in its said first position and opened by said valve member in its said second position.

6. In an air operated device; a housing having a cavity therein open at one end, an air inlet port at one end of the cavity, an air outlet port in the cavity spaced from said inlet port, a feed port in the cavity between said inlet and outlet ports, a first shoulder in the cavity between said inlet port and feed port and facing the open end of the cavity, a second and longer shoulder in the cavity between said feed port and outlet port facing the open end of this cavity, a ring in the cavity resting on said second shoulder, a valve plunger having a shank passing through said ring with clearance and having a head adapted in a first position to sealingly engage said first shoulder and in a second position to sealingly engage said ring, a sleeve in the cavity resting against said ring and having aperture means communicating with said outlet port, a piston portion on the plunger in said cylinder between said aperture means and the open end of said cavity and larger than said head, a bore through said plunger connecting the one side of said head toward said inlet port with the one side of said piston toward the open end of the cavity, and pilot valve means at the open end of said cavity having a first position wherein said bore is closed and the said one side of said piston is connected to the atmosphere and a second position wherein the connection of said one side of said piston to the atmosphere is interrupted and said bore is opened, whereby movement of said valve plunger between its said first and second positions is under the control of said pilot valve.

7. In an air operated device; a housing having a cavity therein open at one end, an air inlet port at one end of the cavity, an air outlet port in the cavity spaced from said inlet port, a feed port in the cavity between said inlet and outlet ports, a first shoulder in the cavity between said inlet port and feed port and facing the open end of the cavity, a second and longer shoulder in the cavity between said feed port and outlet port facing the open end of this cavity, a ring in the cavity resting on said second shoulder, a valve plunger having a shank passing through said ring with clearance and having a head adapted in a first position to sealingly engage said first shoulder and in a second position to sealingly engage said ring, a sleeve in the cavity resting against said ring and having aperture means communicating with said outlet port, a piston portion on the plunger in said cylinder between said aperture means and the open end of said cavity and larger than said head, a bore through said plunger connecting the one side of said head toward said inlet port with the one side of said piston toward the open end of the cavity, and pilot valve means at the open end of said cavity having a first position wherein said bore is closed and the said one side of said piston is connected to the atmosphere and a second position wherein the connection of said one side of said piston to the atmosphere is interrupted and said bore is opened, whereby movement of said valve plunger between its said first and second positions is under the control of said pilot valve, a nut in the open end of the cavity clamping said sleeve against said ring, and a bore in the nut in which said pilot valve is movably mounted, said nut including passage means leading to the atmosphere and controlled by said pilot valve.

8. In an air operated device; a housing having a cavity therein open at one end, an air inlet port at one end of the cavity, an air outlet port in the cavity spaced from said inlet port, a feed port in the cavity between said inlet and outlet ports, a first shoulder in the cavity between said inlet port and feed port and facing the open end of the cavity, a second and longer shoulder in the cavity between said feed port and outlet port facing the open end of this cavity, a ring in the cavity resting on said second shoulder, a valve plunger having a shank passing through said ring with clearance and having a head adapted in a first position to sealingly engage said first shoulder and in a second position to sealingly engage said ring, a sleeve in the cavity resting against said ring and having aperture means communicating with said outlet port, a piston portion on the plunger in said cylinder between said aperture means and the open end of said cavity and larger than said head, a bore through said plunger connecting the one side of said head toward said inlet port with the one side of said piston toward the open end of the cavity, and pilot valve means at the open end of said cavity having a first position wherein said bore is closed and the said one side of said piston is connected to the atmosphere and a second position wherein the connection of said one side of-said piston to the atmosphere is interrupted and said bore is opened, whereby movement of said valve plunger between its said first and second positions is under the control of said pilot valve, a nut in the open end of the cavity-clamping said sleeve against said ring, and a bore in the nut in which said pilot valve is .movably mounted, said nut including passage means leading to the atmosphere and controlled by said pilot valve, a tube reciprocably fitting the bore in said plunger and a head on the tube loosely confined by said nut, said pilot valve sealingly engaging the end of the tube in its first position and sealingly engaging the nut in its second position to close said passage means therein.

9. In an air operated device; a housing having a cavity therein open at one end, an air inlet port at one end of the cavity, an air outlet port in the cavity spaced from said inlet port, a feed port in the cavity between said inlet'and outlet ports, a first shoulder in the cavity between said inlet port and feed port and facing the open end of the cavity, a second and longer shoulder in the cavity between said feed port and outlet port facing the open end of this cavity, a ring in the cavity resting on said second shoulder, a valve plunger having a shank passing t-hrough said ring with clearance and having a head adapted in a first position to sealingly engage said first shoulder and in a second position to sealingly engage said ring, a sleeve'in the cavity resting against said ring and having aperture means communicating with said outlet port, a piston portion on the plunger in said cylinder between said aperture means and the open end of said cavity and larger than said head, a bore through said plunger connecting the one side of said head toward said inlet port with the one side of said piston toward the open end of the cavity, and pilot valve means at the open end of said cavity having a first position wherein said bore is closed and the said one side of said piston is connected to the atmosphere and a second position wherein the connection of said one side of said piston to the atmosphere is interrupted and said bore is opened, whereby movement of said valve plunger between its said first and second positions is under the control of said pilot valve, a nut in the open end of the cavity clamping said sleeve against said ring, and a bore in the nut in which said pilot valve is movably mounted, said nut including passage means leading to the atmosphere and controlled by said pilot valve, a tube reciprocably fitting the bore in said plunger and a head on the tube loosely confined by said nut, said .pilot valve sealingly engaging the end of the tube in its first position and sealingly engaging the nut in its second position to close said passage means therein, a disc between the nut and the cylinder, sealingly engaging the cylinder, and a cavity in the nut adjacent the disc forming the space for loosely confining the head of said tube, the said one side of said piston communicating with said tube and with the said passage means in the nut via the central opening in said disc and notch means formed in the head of said tube.

References Cited by the Examiner UNITED STATES PATENTS 2,641,279 6/1953 Baldwin 137-6256 2,898,936 8/1959 Collins 137-62563 2,913,005 11/1959 Grant et al 137-6256 2,965,132 12/1960 Couffer et al. 137-62564 3,002,532 10/1961 Carlson 137-62566 3,084,672 4/1963 Dalton 91-461 X M. CARY NELSON, Primary Examiner.

MILTON KAUFMAN, MARTIN P. SCHWADRON,

Examiners.

Claims

1. A CONTROL VALVE MECHANISM, WHICH COMPRISES: A HOUSING HAVING A CYLINDER FORMED THEREIN, SAID CYLINDER HAVING COMPRESSED AIR INLET MEANS AND EXHAUST AIR OUTLET MEANS AND A PORT TO BE CONNECTED ALTERNATELY TO SAID INLET AND OUTLET MEANS, PLUNGER MEANS RECIPROCABLE IN SAID CYLINDER FOR CONTROLLING THE COMMUNICATION BETWEEN SAID PORT AND SAID INLET AND OUTLET MEANS, SAID PLUNGER MEANS BEING PROVIDED WITH TWO OPPOSITELY EFFECTIVE AND RIGIDLY INTERCONNECTED DIFFERENT SIZE AREAS, THE SMALLER OF SAID AREAS BEING IN CONTINUOUS COMMUNICATION WITH SAID INLET MEANS AND THE LARGER OF SAID AREAS BEING ADAPTED TO ALTERNATELY COMMUNICATE WITH THE ATMOSPHERE AND TO SAID INLET MEANS SO AS TO MOVE SAID PLUNGER MEANS FROM A FIRST POSITION INTO A SECOND POSITION AND VICE VERSA TO RESPECTIVELY ESTABLISH AND INTERRUPT COMMUNICATION BETWEEN SAID INLET MEANS AND SAID PORT WHILE SIMULTANEOUSLY RESPECTIVELY INTERRUPTING AND ESTABLISHING COMMUNICATION BETWEEN SAID PORT AND SAID OUTLET MEANS, AND A SINGLE MANUALLY OPERABLE VALVE MEMBER ASSOCIATED WITH SAID PLUNGER MEANS AND NORMALLY IN A FIRST POSITION TO EFFECT COMMUNICATION BETWEEN SAID LARGER AREA AND SAID INLET MEANS WHILE INTERRUPTING COMMUNICATION OF SAID LARGER AREA WITH THE ATMOSPHERE AND ALSO MOVABLE INTO A SECOND POSITION FOR INTERRUPTING COMMUNICATION OF SAID LARGER AREA WITH SAID INLET MEANS WHILE CONNECTING SAID LARGER AREA TO THE ATMOSPHERE.