The object of the invention is a torque clutch, used in particular for threading machines and in stationary torque screwdrivers, where it is necessary to precisely adjust the force, the so-called torque.

From the publication of Polish description of invention no. P.393887 there is known a pneumatic overload clutch, which in the case of extensive and predetermined torque load disengages and stops transferring this torque, and once the load has been reduced, it engages spontaneously. This solution is characterised in that a nut, which during startup longitudinally moves a bolt with a non-self-locking thread, has on its outer cylindrical surface small rollers mounted in a radial direction, situated in a single plane perpendicular to the bolt axis, the small rollers protruding from the nut being placed in adjusted grooves of a bushing-housing, and the nut is pressing against a piston with a seal via a thrust bearing and a bushing. Between the piston and a hub there is gas supplied via a valve, and a bearing, preferably conical, abutting the hub, is arranged on the bolt.

From the publication of Polish description of invention no. P.393886 there is known a pneumatic clutch, which in the case of a predetermined and variable torque load responds by changing the torsion angle, this angle being considerably higher than the torsion angles of flexible clutches. The clutch has a nut which during startup is moved longitudinally by a bolt with a non-self-locking thread, which has on its outer cylindrical surface a slip positive connection with a bushing-housing, while the nut presses via a spacer bushing against a piston with a seal, the piston compressing the gas supplied through a valve. The bushing housing is closed from the front by a cover with a venting opening and a cover, and a roller bearing, preferably a thrust bearing, is placed between the nut and the spacer bushing, while a roller bearing, preferably angular, is placed between the bolt and the cover.

From the publication of Polish description of invention no. P.389361 there is known a pneumatic clutch without the switching of disc-shaped hollow flexible members, which ensures flexible transmission of mechanical energy in the driving and driven system of the machine. The pneumatic clutch without the switching of disc-shaped hollow flexible members is intended to provide continuous flexible transmission of the load torque of torsion in torsionally vibrating mechanical systems. The filling of the compression chamber of the clutch with a compressed gaseous medium is provided via valves still before the activation of the system. The load torque of torsion is transmitted from the driving member to the driven member of the clutch through the compression chamber of the given clutch, which is made of hollow flexible elements filled with a gaseous medium. The hollow flexible elements are connected by bolts to a support element, which results in providing perfect tightness of the pneumatic clutch.

The purpose of the invention is to solve the technical problem which involves providing the possibility of precise setting, control and adjustment of the pressure force torque of the clutch in such machines as taps or stationary screwdrivers.

The invention relates to a torque clutch, in particular for threading machines or stationary torque screwdrivers, having a body, in which there is a shaft with a cylinder and an annular piston seated thereon, as well as with sets of bearings. The shaft is rotarily seated in the body and it is supported by an upper and lower bearing, the lower bearing being seated in the recess of the socket mounting the tools connected by its upper part to the lower part of the clutch body and having a disc with recesses, engaging a hub seated on the shaft above the lower bearing, in which hub balls moving on a disc with recesses are seated. The essence of the invention is in that an annular sliding bearing is seated above the shaft hub, on which a pressure disc is seated along with a bearing seated within the lower surface of a cylinder, so that the inner walls of the cylinder tightly abut the outer ring of the bearing, the cylinder placed above the pressure disc having a formed annular recess closed by sealing means, the cylinder being engaged from the top by an annular piston with a flange, in which the upper bearing of the shaft is seated, secured by an inner seating ring, wherein openings for connecting bolts with which the piston is bolted to the body via the flange are made circumferentially on the edge of the piston, so that the flange of the piston rests against the inner walls of the body, the space of the annular recess in the cylinder being connected via a channel to a pneumatic connector connected to the selected outer part of the clutch, the cylinder being a movable part relative to the piston, the body and the shaft.

Preferably, the socket mounting the tools comprises a spindle bushing having a disc, which has a notched upper surface, and in the upper part of the spindle bushing a double bearing is seated, which is secured against sliding off by an inner seating ring, which is installed in the groove of the spindle bushing, and an outer seating ring, which is installed in the groove of the lower part of the body of the clutch.

It is desirable when the annular recess of the cylinder constitutes an airbag, which is filled with compressed air or gas, wherein openings are made circumferentially in the piston from the bottom side, including a through one, wherein a hollow bolt is bolted into the through opening from the bottom side of the piston, while a pneumatic connector is mounted from the top, wherein the space of the cylinder filled with compressed air or gas is sealed by an annular gasket of the piston, which is bolted by means of mounting bolts via a pressure washer to the piston.

It is advantageous when the gasket is provided with an outer pressure spring, pressing the gasket against the outer wall of the recess of the cylinder, and an inner pressure spring, which presses the gasket against the inner wall of the recess of the cylinder.

It is advisable when the gasket is provided with an annular pressure washer, which is seated above the pressure springs.

It is equally preferable when the cylinder has a securing bolt bolted into pass through the opening in the body and block the rotary movement of the cylinder.

It is also desirable when a flexible bladder in the form of a tube is installed in the annular recess of the cylinder, wherein a through opening, in which a conduit supplying air inside the tube via a pneumatic connector is installed, is made radially in the piston.

Preferably, a polyurethane ring shielding the tube is seated between the piston and the cylinder.

The primary advantage of the clutch is providing the possibility of stepless and continuous control and adjustment of the pressure force torque. This has been achieved by the use of a cylinder with an annular recess closed by sealing means, particularly in the form of an airbag or a tube, to which a medium is supplied in the form of compressed air or another gas. This ensures the generation of a pressing force with the possibility of precise and stepless adjustment. The annular recess itself can be easily connected via the pneumatic connector to a pneumatic system. The pressure in the annular recess corresponds to the pressure in the pneumatic system. Therefore, by changing the pressure in the pneumatic system, it is possible to perform arbitrary and stepless adjustment of pressure against the disc of the socket mounting the tools, according to the principle that the higher the pressure supplied to the clutch, the harder the balls push against the disc, which causes the clutch to transmit a higher torque to the working tools. Due to the simple connection of the clutch to the pneumatic system and the dependence of the force torque on the pressure in the annular recess of the cylinder, it is also possible to control the pressure during the operation of the tool. This enables for example compensating for the pressure increase resulting from the heating of individual elements of the device, by reducing the pressure in the pneumatic system, and thus in the clutch. This prevents an unintentional increase in the pressing force torque.

Precise adjustment of the pressing force torque in the clutch also enables protecting the working tool against breaking, or against damaging the element being machined. For example, the clutch allows for protection of the tool or the thread against damage in the case of a high increase in cutting resistance, for example when threading blind openings closed at one end or tightening bolts with a precisely pre-set pressing force. In the case of exceeding the pre-set values and exceeding the pressure against the disc, the balls fall out of the disc recesses and the shaft no longer transmits the torque to the working tools.

The object of the invention is illustrated in embodiments and in the drawing, in which fig. 1 presents a cross-section of the torque clutch using an airbag, fig. 2 - a cross-section of the torque clutch using the airbag in a perspective view, in a partial cross-section, fig. 3 - a cross-section of the torque clutch using a flexible bladder, fig. 4 - an exploded view of the torque clutch using an air chamber, fig. 5 - a connection diagram of the clutch along with additional equipment, and fig. 6 - the torque clutch in a partial cross-section, using the airbag and a pneumatic socket mounting the working tools. In the first embodiment (fig. 1 - 2, 4 - 5), the clutch has a cylindrical body 3, in which a shaft IB is rotarily seated, supported by two ball bearings, an upper one 5 and a lower one 22. The lower bearing 22 is seated in the recess of a socket mounting the working tools, in the form of a spindle bushing 26, having a disc 18 with recesses. The recesses have been formed radially, so that the disc 18 has a notched upper surface, engaging the balls 17 seated in the hub 16 of the shaft 13. After exceeding a pre-set pressure force, the balls 17 move on the notched surface of the disc 18 of the spindle bushing 26. In the upper part of the spindle bushing 26, a double bearing 19 is seated, which is secured against sliding off by an outer seating ring 20, which is mounted in the groove of the spindle bushing 26, and by an inner seating ring 21, which is mounted in the groove of the lower part of the clutch body 3. Above the hub 16, an annular sliding bearing 15 is seated on the shaft 13, on which a pressure disc 14 is seated along with a bearing 12. The bearing 12 is seated within the lower surface of the cylinder 2, so that the inner walls of the cylinder 2 abut tightly to the outer ring of the bearing 12. From the top, the cylinder 2 has a formed annular recess closed by sealing means, which simultaneously constitutes an airbag in which compressed air is stored. The position of the cylinder 2, seated inside the body 3 of the clutch, on the shaft 13, is fixed by means of a securing bolt 27, which prevents the rotation of the cylinder 2 on the shaft 13 inside the body 3. Wherein the securing bolt 27 does not restrict the longitudinal movement of the cylinder 2 relative to the body 3 of the clutch, since the opening made in the body 3, through which the securing bolt 27 passes, has a greater height than the range of the longitudinal movement of the cylinder 2. The cylinder 2 is engaged by the annular piston 1, in which the upper bearing 5 is seated, secured by the inner seating ring 4. Openings made circumferentially on the edge of the piston 1 are for connecting bolts 23, with which the piston 1 is bolted to the body 3 via a flange 25, so that the flange of the piston 1 rests against the inner walls of the body 3.

Threaded openings are made circumferentially in the piston 1, including one through opening. A hollow bolt 10, used to supply air to the space of the airbag inside the cylinder 2, is bolted inside the through opening, from the bottom side of the piston 1. This is enabled by a pneumatic connector 24, installed on the outer surface of the piston 1, on the hollow bolt 10. The pneumatic connector 24 allows for attaching a conduit and supplying compressed air which powers the clutch. The airbag, meaning the space of the annular recess 40 of the cylinder 2 filled with compressed air, is sealed by the annular gasket 6 of the piston, which is bolted by means of the mounting bolts 11, via the pressure washer 9, to the piston 1. The cylinder 2 is a movable part relative to the piston 1, the body 3 and the shaft 13. The sealant, meaning the gasket 6, is provided with an outer pressure spring 7, pressing the gasket 6 against the outer wall of the recess of the cylinder 2, and an inner pressure spring 8, which presses the gasket 6 against the inner wall of the recess of the cylinder 2. The pressure springs 7, 8 are seated in grooves made in the gasket 6. The annular pressure washer 9 of the sealant is placed above the pressure springs 7, 8. The washer mounts the seal 6 to the piston 1 and protects the seal 1 against deformation. The seal 6 prevents the leakage of compressed air from inside the airbag of the cylinder 2.

The spindle bushing 26 has inside it a Morse taper opening, used for seating tools such as a tap handle 28, in which a tap 29 is mounted, along with an adapter 30 for socket spanners 31 and drill bits, reamers, as well as other working tools.

Fig. 5 presents a connection diagram of the clutch along with additional equipment. An expansion tank 32 provided with a pressure sensor 34, used to control air pressure in the tank 32 and in the clutch airbag, is connected via a conduit to the pneumatic connector 24 of the clutch. In addition, an air supply valve 35 and a draining valve 36 discharging the air are connected to the expansion tank 32. The entire installation of compressed air and adjustment of the amount of air operate by means of a connected controller 33. The tank 32 compensates pressure changes in the airbag of the clutch.

In the second embodiment of the clutch (fig. 3), a flexible bladder in the form of a tube 37, also serving the function of sealing means, has been placed in the annular recess 40 of the cylinder 2. A through opening, in which the conduit 39 supplying air inside the tube 37 via the pneumatic connector 24 is installed, is formed radially in the piston 1. In addition, a polyurethane ring 38, shielding the tube 37 and protecting it against damage, is seated between the piston 1 and the cylinder 2.

In the third embodiment of the clutch (fig. 6), the annular recess 40 of the cylinder 2 is closed by the piston 1, the sealing means in the form of gaskets 6 being placed in the lower part of the piston 1. The annular piston 1 itself has an upper and a lower part, the upper part being connected to the body 3 using the connecting bolts 23 and having the upper bearing 5 seated therein.

Air or another medium is supplied to the recess 40 of the cylinder 2 via a channel made in the piston 1, also passing through the body 3, via the pneumatic connector 24 connected to the outer part of the body 3.

Like in the previous embodiments, the disc 18 of the socket mounting the tools has recesses engaging the balls 17 seated in the hub 16 of the shaft 13. The recesses in the disc 18 have the form of openings made in the disc 18, which receive the balls 17.

The socket 26 mounting the tools has the form of a complex adapter connected with bolts passing through the flange of the body 3 of this socket. The mounting socket 26 is also provided with a pneumatic handle for extending the tip mounting the working tools, such as a tap handle 28 or an adapter for socket spanners.

The operating principle of the torque clutch is that a medium in the form of compressed air from the expansion tank 32 is supplied inside the annular recess 40 in the cylinder 2, and thus into the airbag in the first and the third embodiment, or the tube 37 in the second embodiment. Compressed air supplied into the airbag or the tube 37 ensures the generation of force pushing against the cylinder 2, which by means of executive elements presses the balls 17 of the hub 16 of the shaft 13 against recesses in the surface of the disc 18. The airbag or the tube is filled with air to a predetermined pressure, wherein the higher the pressure, the stronger the pushing of the balls 17 against the disc 18, which causes the clutch to transmit higher torque to the socket 26 mounting the working tools. The pressure supplied to the recess 40 in the cylinder 2 can have any value, enabling stepless adjustment of the force pressing against the disc 18, and therefore the torque against the socket 26 mounting the working tools, and precise adjustment of the force torque.