DE1775599A1 - Torque-dependent clutch - Google Patents

Description

Torque dependent clutch

The invention relates to a torque-dependent clutch which has a drive connection between a driving one and a driven part releases when the on the driven part Part of the applied torque load a predetermined Amount exceeds · The Drehaoaentabhtngige according to the invention Coupling is particularly suitable for use in tools, through which a torque on fasteners, how s. B. screws, bolts or the like «is transferred} such tools are power-operated wrenches,

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Screwdriver or the like

When screwing in a screw, a bolt, a nut or any other threaded fastening means in its fastening position, power-operated tools are used in many cases which have a torque-dependent coupling which automatically interrupts the transmission of the torque exerted on the fastening means, if the fastening means has reached a ^ end division and here a predetermined drelu ** ment on this fastening means, e.g. B * a screwed-on nut is exercised. In order to avoid that the operator receives jolts from the tool, the coupling must interrupt the transmission of the torque very quickly unpleasant effects on the operator during the interruption process · other side lot; requires that during the engagement of the Kupplun # ^ parts emanating from the motor in the tool drive on da · fastening means, for "B · festzudrehende the mother, as rigid as possible, <t _# h,

themselves

is transmitted resiliently, so that * results in an effective transmission of the torque · On the other hand, if the clutch is loaded once, the transmitters «; of torque are completely interrupted mm unwanted Prnhmomnnt-effects on the operator mm vwrhlndei

It is also desirable that the clutch not prematurely during the initial start-up and the acceleration of the tool motor triggers * This undesirable effect occurs very often in power-operated, with Couplings provided bolt wrenches or the like. The reason for this is the inertia of the force transmission in the tool, which counteracts the acceleration forces generated by the motor, creating a so high instantaneous load occurs that the clutch loosens.

Another difficulty encountered with powered, mi ~ t A bolt wrench or the like provided with a coupling occurs, is due to the efforts of the coupling again to take effect after the manual throttle valve is closed and before the tool motor comes to a standstill. This behavior of the clutch is undesirable because this causes shock loads to be exerted on the coupling, which can easily lead to the destruction of the coupling «e.g. the clutch teeth are often disengaged or disengaged in this way. erupted

Finally, the aim is to ensure that the motor of the wrench or the like is automatically stopped when the clutch loosens in order to save energy and at the same time

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service person the end of the screw-in od. The like. Process to display. Usually the means provided for stopping the engine are mechanical with the clutch Connection that runs axially through the motor, thereby reducing the construction of the mechanical connection, of the motor and the housing of the bolt wrench or the like gets complicated.

Finally it is desirable to have a torque dependent clutch available that is constructed in such a way that very little or virtually no wear and tear during the normal service life of the bolt wrench or the like occurs. Usual bolt wrenches or the like are with jaw or claw couplings equipped, in which wear during loosening and engagement of the coupling cannot be avoided.

The object of the invention is to provide a torque-dependent clutch of relatively simple mechanical construction create in which the aforementioned difficulties are avoided or largely eliminated and the above are desired Has advantages.

In particular, the invention should be torque-dependent Release clutch by itself at a predetermined torque load, with torque interruption at high speed and should be done completely. The clutch after the

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finding should be at a predetermined torque value be adjustable, in which the clutch transmission is interrupted »The clutch mechanism should be before the solution of the clutch, the torque is rigidly transmitted and after the clutch has been released, no torque is transmitted at all torque dependent clutch is designed to work with a normally open engine valve, and in such a way that the clutch is released when the engine valve is closed. ”Furthermore, the torque-dependent clutch should and the power or motor cut-off device be relatively simple and no bolt, no rod or the like, which passes through the tool motor · At the coupling according to the invention has extremely low wear values during the normal life of the wrench od. The like. Desired «Furthermore, the invention is intended to provide a tool with a torque-dependent clutch in which the clutch does not calibrate during the initial acceleration of the tool motor prematurely solves «The tool according to the invention is intended to be a Have a torque-dependent clutch that does not re-engage prematurely after the throttle valve closed and before the tool motor is stopped.

This task is performed by a power operated bolt wrench od. Like. Solved, the inventive rotary

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Has torque-dependent clutch in the drive part of the tool and an interrupt valve in the outlet channel of the pneumatic motor, which when responding the torque-sensitive device is closed at a «predetermined torque, the clutch is opened at the same time by closing the interrupt valve. The coupling according to the invention is a "cone

Ever
^{Coupling 11} with a coupling or locking surface, which can be released from one another very quickly, so that both wear and a sudden reaction on the operator is avoided.

The torque-dependent clutch according to the invention has a driving and a driven part and a pair Coupling elements that are relative to each other and χα a « of the drive parts are displaceable, one of the coupling elements with the driven part for transmission a driving force is connected and elastic means are provided which press the coupling elements and the driving part against each other · This coupling is characterized according to the invention by a coupling element with one of the two drive parts for the transmission of a Torque-engaging control that takes effect at a predetermined torque load in such a way that that the one coupling element and the driving · part against

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the force of the elastic means are moved away from each other, whereby a distance between the one coupling element and the driving part limiting counterstop is provided which prevents the one coupling element Comes completely out of engagement with the driving part, so that the one coupling element and the driving Part continuously for the transmission of a torque - * are engaged between the two and wherein further means are provided which are responsive to the movement of the over a predetermined distance from the driving Tel ^ moved away address one coupling element and disengage the other coupling element with this «

In the following, the invention is particularly preferred with the aid of some of those shown in FIGS. 1 to 8 of the description AusfUhrungsbeispiele explained in more detail * It show;

Fig. 1 is an elevation, partly in section, of a pneumatic Vinkel bolt wrench with an inventive torque-dependent clutch, the clutch in its normally given engagement position and the tool cutoff valve is shown in its normally given open position are;

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FIG. 2 shows a partial section of the coupling and the pneumatic actuating device according to FIG. 1 _t, with individual parts broken out and an enlarged scale selected, the coupling being disengaged and the interruption valve completely closed; FIG.

Fig. 3 is an exploded perspective view the clutch;

FIG. K a ^s: express ways longitudinal _section) is shown in which the clutch performing in an engaged position a view;

FIG. 5 shows a representation as in FIG. _9, but with the torque-dependent part of the clutch shown under load and the interrupt valve is in a central position; FIG.

FIG. 6 shows a partial section according to FIG. 2, however, of a second embodiment of the invention, in which case one Cut-off valve is used, which move relative to the clutch over a predetermined distance can)

Fig. 7 is a partial section corresponding to FIG. K of an "

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third embodiment of the invention with a modified torque sensitive control and

Fig. 8 is a view of the rotation control according to FIG. 7 in a developed view, in which the circumference on a Level is unwound.

The shown in the drawing pneumatically driven angle-bolt wrench 1 has a housing 2 with a rear end part 3 and a working head 4. The rear end part 3 carries a pivotable throttle valve lever 5 $ is "acts on a valve stem 6 by pressing down of the throttle valve Hebele 5, the throttle valve 6 is opened and the rotary motor 7 provided in the housing 2 is subjected to a pneumatic pressure " A rotary spindle 8 of square cross-section is provided on the working head k , which can be connected to a socket (not shown) of a bolt wrench for screwing in nuts or bolts" The motor 7 drives the spindle 8 via a clutch 9 and a planetary gear "The invention relates to the clutch 9 and an automatic shut-off device for the motor"

The motor 7 has a shaft 11 with a serrated front end 12 '. This shaft can be rotated in a housing

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provided ball bearing mounted «A clutch driver 13 is wedged to the front end 12 of the shaft 11 *

The planetary gear 10 includes a sun gear 15 which is on front end of the housing 2 is arranged. The sun gear 15 is supported by a main drive shaft that is lumpy in each case 17 driven, which is rotatably mounted in a bearing 18 near its front end «on the rear end the main drive shaft 17 is a cup-shaped clutch disc 20 slidably wedged on by means of a number of wedging balls 21 · Furthermore, is on the coupling driver 13 a conical clutch disc 22 rotatably attached, which engages in the cup-shaped clutch disc 20 · The cone angle of the clutch disc 22 and the conically shaped Recess 23 in the cup-shaped clutch disk 20 relative to the axis of the clutch disks is 8 ° or less, so that the two conical pits have a "blocking conicity" own. By "interlocking conicity" is meant the fact that the two surfaces automatically are locked against each other during the intervention and it is necessary to push them apart to cancel the intervention

The clutch driver 13 and the conical clutch disc 22 are interconnected by a set of control balls 25. These control balls 25 engage in corresponding control grooves 26 and 27 in the coupling driver 13 and the coupling

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disk 22 on * The control balls 25 transmit the torque from the coupling hub 13 to the coupling disk 22 and interact with the control grooves 2.6 and 27 in such a way that the two coupling elements are pushed apart under torque load «

The coupling driver 13 has a hollow front Pin 29, which receives the clutch disc 22 and the rear end of the main drive shaft 17 rotatably. The pin 29 is provided with an annular groove 30 which receives a spring ring 31, which acts as a limit stop the movement is used by which the control balls 25, the clutch disc 22 and the clutch driver 13 move away from each other The spring ring 31 is arranged in such a way that that the clutch disc 22 is continuously wedged with the clutch driver 13; these two components will be therefore not completely separated from each other.

The front clutch disk 20 is rotatably connected to a spring washer Jh by means of a bearing 33. A spring 35 rests against the spring washer 3k and acts in such a way that the two coupling parts 20 and 22 are pressed from the rear against the coupling driver 13. The front end of the spring Housing 2 provided pipe 37

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wedges is. The spring seat 36 rests on one on the tube 37 screwed on nut 38. The mother owns 38 a toothing 39, over which it is by means of a "Jakobs" clamping wrench 40 can be rotated, whereby the effective pressure of the spring 35 is adjusted. Oer spanner 40 is pulled out after adjusting the spring pressure. This type of adjustment of the spring pressure is known per se «

The fluid for driving the motor 7 is supplied to it via the throttle valve 6 through the input channel 43. After passing through the engine, this fluid is discharged via the outlet channel 44. The outlet channel 44 extends forwardly within the housing to a normally open interrupt valve 45 into a chamber 46, in which the spring 35 is located. The chamber 46 is with connected to the outside atmosphere via a multiplicity of passages provided in the housing 2 surrounding it Interrupting valve 45 is molded onto the spring washer 34 and designed so that it is in an annular shape on the inside of the housing 2 provided valve seat 48, which surrounds the valve 45, is seated.

The interruption element 45 carries on the rear end an annular extension piece 49 · The extension piece 49 engages slidable in a forwardly directed annular flange 50, with an O-ring seal on the extension piece 49 51 to prevent air leakage through the coupling '

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parts provided 1st

The valve seat 48 has a rear shoulder 52, a front shoulder 53 and one of the two shoulders connecting bore 5 ^ · Now when the cut-off valve 45 moves forward, it initially slides past the rear shoulder 52 so that the outlet channel 44 is fully completed · After that you can

the cut-off valve 45 along the bore 54 such as move a piston in a cylinder until its front end rests on the front shoulder 53. This additional piston-like movement of the interrupt valve 45 after the closure of the outlet channel is therefore provided, so that the full differential pressure for releasing the clutch disks 20 and 22 builds up at this interrupt valve can.

The rear shoulder 32 of the valve seat 48 is arranged so that the interrupt valve 45 initially closes the valve seat 48, immediately before the Clutch disc 22 has been pushed away from the clutch driver 13 to the full extent, as shown in Pig 5 In this position, the interruption valve 45 has the outlet channel completely closed, so that the motor 7 stopped and a high differential pressure at the interrupt valve 45 is generated »When generating this high difference

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pressure, the cut-off valve k5 is moved further like a piston along the bore 5> h in order to release the clutch by pushing the clutch disc 20 away from the clutch disc 22 after the clutch disc 22 hits the spring ring 31, whereby a further forward movement Clutch disc 22 is prevented. The clutch disengages very quickly because of the "locking conicity" of the clutch disks 20 and 22 ·

The operation of the device described above is as follows

When the bolt wrench 1 stands still, the clutch disks 20 and 22 are in engagement, the interruption valve k5 is open and the throttle valve 6 is closed The predetermined torque value at which the bolt wrench switches off is set by the load on the spring 35 This is done by means of of the turnbuckle kO _t with which the nut 38 is rotated. After setting the bolt wrench 1, the clamping wrench kO is pulled out and stored separately until it is necessary to change the holding torque

After the bolt wrench 1 with a compressed air line connected and a predetermined bolt socket is placed on the spindle 8, the operator brings the

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Bolt socket In working position and presses the throttle valve lever 5 down so that the throttle valve 6 is opened and compressed air is introduced into the engine 7. As soon as the motor 7 begins to rotate, it drives the spindle 8 via the clutch driver 13, the clutch disks 20 and 22 as well as the main drive shaft 17 and the planetary gear 10.

The torque load absorbed by the bolt wrench reaches the control balls 25, which cooperate with the bull grooves 26 and 27 in such a way that they push the clutch disc 22 away from the clutch driver 13. The control force generated by the control balls is resisted by the spring 35.Therefore, the pressure of the spring 35 determines the torque value at which the control balls 25 push the clutch disc 22 away from the clutch driver 13 so that the cut-off valve h5 throttles the outlet channel for the motor is throttled or closed by the interrupt valve h5 , a differential pressure builds up at the interrupt valve 45, which pushes it forward against the valve seat 48.

When the differential pressure arises , the interruption valve k5 quickly changes to the position shown in FIG. This switches off the motor 7

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At this moment the clutch disks 20 and 22 are still fixed to one another by their "locking conicity" on the conical surfaces. If the full pressure now acts on the interruption valve 45, this is relatively quickly displaced forwards within the bore 5k , as a result of which the clutch disks 20 and 22 ^{n are} torn apart ⁿ *

Due to the higher force of the connection between the clutch discs 20 and 22 is required to "tearing apart ¹ x, these dissolve when separating from each other extremely fast" This disengagement of the clutch plates is substantially simultaneous with the switching off of the motor 7 ·

The clutch disks 20 and 22 disengage from each other so quickly that an impact of the bolt wrench on the operator is practically avoided · In contrast, the usual Bolt wrench when screwing in a bolt, when unscrewing a nut or when screwing in other ways of a lock to bumps on the operator pereon, since the The couplings used here loosen too slowly «Furthermore, the two engaged coupling parts loosen the clutch according to the invention at such a high speed, that wear of the coupling parts is practically largely avoided.

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Stopping the engine by closing the exhaust port takes place quickly and prevents the engine from starting a further rotation, since the rotation of the motor after the closing of the interrupt valve 45 creates a "back pressure" generated, which leads to a rapid termination of the rotational movement of the motor 7.

After the motor has stopped, the operator releases the throttle valve lever 5 so that the throttle valve 6 can close. The tool is then lifted off. As soon as the throttle valve 6 is closed, the pressure in the engine 7 drops very quickly to atmospheric pressure as a result of the normally existing leaks. In addition, the shaft 6 of the throttle valve can be provided with a groove 55 shown in FIG. 1, through which the inlet channel 43 is automatically connected to the outside atmosphere when the throttle valve 6 is closed.

If the pressure prevailing in the motor 7 and acting on the cut-off valve 45 drops, this pressure is not more able to force the cut-off valve 45 against to keep the spring 35 closed. Therefore, the cut-off valve 45 and the clutch disks 20 and 22 open enter into engagement with one another again, as shown in FIGS. 1 and 4. After the clutch disks 20 and 22 are in engagement with each other again, the bolt

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key 1 is available for further work.

In the second preferred embodiment of the invention shown in Fig. 6, the interrupt valve 45 is on the Bearing 33 and the extension piece 49 at a low limited relative displacement (backlash) arranged. In the rear End of the valve 45 is a blocking ring 56 as well as one Washer 57 is provided. There is also a light spring 58 between the washer 57 and the front flange 59 of the extension piece 49 inserted. The spring 58 pushes the cut-off valve 45 backwards onto the extension piece 49. The sliding movement the cut valve 45 and the bearing 33 is limited by a second blocking ring 60 arranged within the ring-shaped interruption valve 45 «

The fact that the interruption valve 4-5 relative to the can move front clutch disc 20, it is ensured that the interrupt valve closes quickly as soon as a small pressure differential occurs across this valve. This backlash causes that occurring at the interrupt valve 45 Pressure difference the valve closes before the pressure difference is large enough to separate the clutch disks 20 and 22 from each other to solve. As soon as the interrupt valve 45 on the rear Shoulder 52 of the valve seat 48 slides past, the Outlet channel 44 closed, and the differential pressure at that Interrupt valve 45 rises very quickly to a maximum

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value that leads to the two clutch disks 20 and 22 can be released from each other quickly.

The third particularly preferred exemplary embodiment of the invention shown in FIGS. 7 and 8 has been developed in order to improve a further function of the device according to the invention, which corresponds to the function improved by the second exemplary embodiment. In the third embodiment it is achieved that the closing of the interruption valve k5 is initially opposed to a greater resistance than the force that acts afterwards when the torque-dependent parts (clutch disc 22, control balls 25 and clutch driver 13) under the action of a torque by a predetermined Amount have been separated from each other. Therefore, as soon as it begins to close and has moved towards the closed position by a predetermined amount, the interrupt valve can also continue to close, even if a lower torque is applied than is required to initiate the closing process. This advantageously ensures that the interruption valve h5 does not remain in a partially closed position, which could otherwise easily happen if the force generated by the motor drops excessively due to the narrowing of the exhaust duct before the interruption valve k $ is completely closed. If that is because of the force made available by the motor cur

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the narrowing of the outlet channel drops excessively, then this is no longer able to apply a sufficient * torque to completely close the valve k5 .

In the third particularly preferred exemplary embodiment of the invention, each of the control grooves 62 and 63 in the clutch driver 13 or the rear clutch disc 22 is provided with a double-stepped slope, namely with an initial control slope 64 which is relatively straight and a second control slope 65 »their Inclination angle is much smaller «The two control inclinations 6k and

65 are connected to one another by a control curve bend 66.

In order to move the interruption valve k 5 forwards, the control balls 25 must overcome the initial control inclination and roll away over the control curve bend 66 · After the control balls 25 have once over the control curve bend

66 have passed, they can roll over the second control slope 65, even if less torque acts on the clutch mechanism than is necessary for the control balls 25 to overcome the initial control slope 6k.

Another measure that ensures that the interruption valve 45 is not in a partially open position

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remains, consists in increasing the inclination of the control grooves 26 and 27 in the embodiment shown in FIG. 1 to such an extent that the spring 35 can be relatively weak. If the spring 35 is comparatively weak, the interruption valve k5 is already closed at a minimal pressure difference generated at this valve by slight throttling «

Of course, the invention is not limited to the exemplary embodiments described above, but can under the guidelines given here as well as in the context of the general inventive concept in a variety of ways with success be realized.

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Claims (1)

PATENT LAWYERS PATtMTANWALT DIPL-ING. R. M O LLE R-BORN ER 1 ^ 3 PATENT ADVERTISEMENT DIPL-ING. HANS-H. W. B E R LI N - DAHLEM 33-PODBIELSKIALLEE68 ~ * 8 MUNICH ». WIDENMAYERSTRASU TEL. 0311 · 762907 ■ TELEGR. PROPINDUS TELEX 0184057 TEt. 0811 -225585 - TELEGR. PROPINDUS. TELEX üj2I 21 387 Ingersoll-Rand Company-New York, N.Y. / UNITED STATES Claims 1 · Torque-dependent clutch with one driving (11) and a driven part (17) and a pair of coupling elements (20, 22) which are displaceable relative to one another and to one of the drive parts (11) are, wherein one of the coupling elements (20) is connected to the driven part (17) and elastic Means (35) are provided which press the coupling elements and the driving part (11) against one another, characterized by a coupling element (20) with one of the two drive parts (11) ■ -2- 109837/0525 -SX- for transmitting a torque engaging control (13,25), which at a predetermined torque load is effective in such a way that the one coupling element (20) and the driving part (ii) against the force of the elastic means (35) are moved away from each other, one being the distance between the one Coupling element (2O) and the driving part (11) limiting Counterstop (31) is provided which prevents the one coupling element (20) from being completely comes out of engagement with the driving part (11), so that the one coupling element (20) and the driving Part (11) continuously for the transmission of a torque between the two are in engagement with one another and wherein further means (^ 5,48) are provided, which on the movement of the one coupling element moved a predetermined distance away from the driving part (11) (20) respond and bring the other coupling element (22) out of engagement with this (20). 2. Coupling according to claim 1, characterized in that the coupling elements (20,22) are normally engaged with one another by means of a device (22,23) which is designed so that a greater force to initially disengage the coupling elements (20,22) than to the separation of which is required after the initial disengagement. -ΟΙ 098 37/0525 -5- 3, coupling according to claim 1 or 2, characterized in that the coupling elements have a conical surface (22), the one 'engages in a conical bore (23), both having a ^"1 · Verblockungskonizität. k » Power-operated tool, in particular bolts, screws or the like wrenches or pullers with a torque-dependent coupling according to one of Claims 1 to 3» comprising a housing (2) in which a fluid-operated motor (7) is located, characterized in that the driven part (17) is connected to the motor (7), a normally open valve (** 5) being provided which controls the flow of fluid through the motor (7) and reacts to the movement of the one coupling element ( 20), which is moved a predetermined distance away from the driving part (11), responds in such a way that it disengages the other coupling element (22) from the former coupling element (2θ). 5. Power-operated tool according to claim k _t, characterized in that the valve (^ 5) is actuated by a differential pressure for releasing the coupling elements (20, 22). 6. Power-operated tool according to claim k or 5 »thereby -I ₁ - 0983 7/0525 characterized in that the valve (45) in one with the engine (7) connected Auelaßkanal (44) is arranged. 7. Power-operated tool according to one of claims 4, 5 or 6, characterized in that the coupling elements (20, 22) and the valve (45) in front of the motor (7) are arranged « 8. Power operated tool according to claim 6 or 7, characterized characterized in that the outlet channel (44) comprises an annular channel which the coupling elements surrounds and is enclosed in the housing (2) and that the valve (45) is annular and for stopping the engine (7) is arranged displaceably in the annular channel to close the channel. 9. Power-operated tool according to claim 8, characterized in that that the annular valve (45) with the other coupling element (22) for common movement connected is" 10.Power-operated tool according to claim 8, or $ 9 characterized by a connection (6o) between the annular valve (45) and the other coupling element (22), 109837/0525 1775593 VL which enables the valve {k5) to be movable a predetermined limited distance in front of the other coupling element (22) before the coupling elements (20, 22) disengage. 11. Power-operated tool according to one of Claims k to 10, characterized in that the control (13, 25) has a stepped driver or the like (64, 65) which is designed in such a way that a greater torque load is required for the application of the solution in which the one coupling element (20) separates from the driving part (11) is required than for the progress of the solution after the one coupling element (20) moves a predetermined initial distance away from the driving part (11) Has. 109837/0525