EP0239830B1 - Device for adjusting the relative rotational position between a toothed wheel and a coaxal toothed crown - Google Patents

Description

The invention relates to a device for adjusting the relative rotational position between a gearwheel and a gear rim which is concentric therewith and rotatably arranged on an annular shoulder of the gearwheel, with radially arranged pressure levers which can be actuated jointly by an axially adjustable, centrally arranged adjustment process and by means of which a spring force is used to achieve this non-positive connection of adjoining end faces of the gear wheel and ring gear can be released by reducing the spring force acting on these end faces.

When converting from sheet-fed rotary printing presses to optional straight printing or perfecting, it is necessary to adjust the relative rotational position between a gearwheel arranged on the shaft of the reversing drum and a sprocket mounted coaxially with it. The gear rim is clamped to the gearwheel during operation of the printing press. This requires considerable forces to ensure that the rotational position of the ring gear is securely fixed in relation to the gearwheel during operation. To adjust the rotational position, the tension is released, the sprocket rotated by the desired angle and then its rotationally fixed connection to the gear is restored.

In known devices, the loosening and tightening of four to six screws is required.

To simplify the changeover, devices have become known (DE-A-31 27 539, JP-A-58-78763) in which the screws are rotated via a common drive with gears or worms.

Furthermore, a coupling device has become known (JP-A-58-71162), in which a non-positive connection between the ring gear and the gearwheel is achieved with the aid of a plurality of clamping elements arranged in the vicinity of the circumference, which can be released from a centrally located screw via levers. These levers are pivotally mounted on pins and have screw connections by means of which the adjustment movement of the central screw is transmitted to the coupling parts.

The known devices have the disadvantage that the printing machine can also be started up if, after the changeover, the ring gear is not firmly connected to the gear again. As a result, the relative rotational position between the ring gear and the gearwheel can be adjusted during operation of the printing press, which can result in damage to the printing press.

The object of the invention is to propose a generic device which, with the least possible manufacturing and assembly work, ensures a secure coupling between the gearwheel and ring gear during the operation of a printing press equipped therewith.

This object is achieved with a device according to claim 1.

The device according to the invention has the advantage that an adjustment of the relative rotational position between the gear and the ring gear is possible with little effort. This simplifies the operation of the printing press. This ease of operation increases the security against incorrect operation.

The adjusting member is movable within a path which comprises a first section in which the spring force acting on the coupling elements increases from a low value to a value required to maintain the relative rotational position, and a second section in which the required to maintain the relative rotational position Spring force is at least maintained and in which an electrical switch can be actuated, which is arranged in the supply circuit of a drive device.

This ensures that the printing press can only be put into operation if there is a sufficiently firm coupling between the gear and the ring gear. As soon as the adjusting member is moved from its end position to release the toothed ring, the supply circuit of the drive device for the printing press is first interrupted and then a reduction in the coupling forces is effected.

The pressure levers are loosely inserted between the annular shoulder and a tensioning disk in the radial lever guiding the pressure lever and are pivotally supported on one of these two parts in a first bearing area located between the ends of the respective pressure lever on its outer contour.

This eliminates the need for journal bearings for the pressure levers and screw connections for transmitting the adjustment movement of a central adjustment element to the coupling parts, so that production and assembly require less effort.

One design option is that in each case second contact areas of the pressure levers rest on an end face of the ring gear facing away from the gearwheel and that third contact areas of the pressure levers, which form longer lever arms with the first contact areas than the second, near the axis area of the gearwheel by a compression spring with an axial Directed force can be applied and that the axially movable, threaded actuator within a first part of the adjustment path executes a movement independent of the compression spring and tensions the compression spring within a second part of the adjustment path.

This configuration has the advantage that only a compression spring is required, which can be put together in a suitable manner from plate springs, and that the adjusting member covers the path required for actuating the switch without load.

Another possible embodiment of the invention is to be seen in that by several resilient clamping elements connecting the gearwheel and the tensioning disk, the toothed ring is clamped between the gearwheel and the tensioning disk such that the pressure levers, with their short lever arms each formed between a first and a second support area, are mounted between the gearwheel and the tensioning disk in such a way that they act on due to the force separate the third contact area against the spring force of the clamping elements, the clamping disc from the ring gear.

This embodiment of the device according to the invention also has the advantage that the adjusting member can be easily rotated within the path required for actuating the electrical switch.

Finally, a further advantageous embodiment of the invention is that the pressure levers which can be acted upon by an axially directed force from the adjusting element in the region of the gearwheel near the axis and which form a long lever arm between the first and the second bearing areas are elastically deformable and that the adjusting element is within the for the adjustment of the intended path causes a deformation of the pressure lever.

This embodiment of the invention requires very few components and is therefore particularly simple to manufacture.

A further development of this embodiment consists in the fact that the adjusting element consists of a sleeve with an external and an internal thread, that the adjusting element is mounted in a central threaded bore of the tensioning rail and that a screw which interacts with the internal thread of the sleeve is axially displaceably but non-rotatably mounted, and that the third contact areas of the pressure levers bear against the contact surface of the head of the screw and that the pitches of the external and internal threads differ slightly from one another.

This development advantageously creates a path of the adjusting member required for actuating the switch.

Advantageous further developments and improvements of the invention are possible through the measures listed in the further subclaims.

• Fig. 1 einen Schnitt durch ein erstes Ausführungsbeispiel in einem ersten Betriebszustand,
• Fig. 2 einen Schnitt durch das erste Ausführungsbeispiel in einem zweiten Betriebszustand,
• Fig. 3 eine Draufsicht des ersten Ausführungsbeispiels,
• Fig. 4 einen Schnitt durch ein zweites Ausführungsbeispiel,
• Fig. 5 die Draufsicht des zweiten Ausführungsbeispiels und
• Fig. 6 einen Schnitt durch ein drittes Ausführungsbeispiel.

Embodiments of the invention are shown in the drawing and explained in more detail in the following description. It shows:

• 1 shows a section through a first exemplary embodiment in a first operating state,
• 2 shows a section through the first exemplary embodiment in a second operating state,
• 3 is a top view of the first embodiment;
• 4 shows a section through a second exemplary embodiment,
• Fig. 5 is a top view of the second embodiment and
• Fig. 6 shows a section through a third embodiment.

Identical parts are provided with the same reference symbols in the figures.

In the embodiment shown in Figures 1 to 3, a gear 1 is arranged at one end of a shaft 4. Bearings of the shaft 4, a turning drum carried by the shaft 4 and further parts of a printing press are not shown since they are not necessary to explain the invention. The gear 1 is held on the shaft 4 with a plurality of screws, of which only one screw 5 is shown.

A ring gear 2 is rotatably mounted on an annular shoulder 3 of the gear 1. On the end face of the annular extension 3, a tensioning disk 7 is fastened with screws 6, which has six radial grooves 8 on the side facing the gearwheel 1, each receiving a pressure lever 9 which also extends radially.

Provided on the pressure levers 9 are a first contact area 10 for support against the tensioning disk 7, a second contact area 11 on the outer lever end for transmitting the clamping force to the ring gear 2 and a contact area 12 on the inner lever end for introducing the lever force.

The lever arm formed between the support areas 10 and 12 is substantially larger than the lever arm formed by the support areas 10 and 11, so that the ring gear 2 by applying a relatively small force to the pressure lever 9 on the support areas 12 with a relatively large force between the pressure lever 9 and the gear 1 is clamped, whereby a non-positive coupling between the ring gear 2 and the gear 1 takes place.

A pin 13 is screwed into the center of the end face of the shaft 4 and has several sections in the longitudinal direction. A first section 14 has a hexagon for screwing in the pin, which at the same time serves as an abutment for a compression spring 15, which takes up a second section 16 of the pin 13. The compression spring 15 consists of disc springs which are assembled in a manner known per se in such a way that a suitable spring travel results with a suitable spring constant.

On a third section, which has a smaller diameter than section 16, a disk 17, a cage with rollers 18 and a sleeve 19, which form an axial thrust bearing, are slidably mounted in the axial direction. The disc 17 transmits the force of the compression spring 15 to the support areas 12 of the pressure lever 9. The clamping thus achieved between the gear 1 and the ring gear 2 is sufficient to prevent the ring gear 2 from rotating with respect to the gear 1 in all operating states of the printing press.

A fourth section 20 of the pin 13 is provided with a thread onto which a threaded sleeve 21 is screwed as an adjusting member. The threaded sleeve 21 is provided with a hexagon 22 and can therefore be screwed from the position shown in the direction of the spring with the aid of a corresponding key. To limit the path of the threads sleeve 21 has an annular groove 23 in which a stop 24 engages. A lever 26 engages in a further annular groove 25 of the threaded sleeve 21. The lever 26 is fixed at 27 and is pressed against a stop 29 by means of a spring 28. In this position, the lever 26 releases the confirmation element 30 of an electrical switch 31.

1 shows the operating state of the arrangement in which the gear 1 and the ring gear 2 are coupled to one another. The electrical switch 31 is accordingly connected to an electrical control (not shown) of the printing press in such a way that the machine can be operated in the position shown in FIG. 1.

Fig. 2 shows a section through the same embodiment - but in a different operating state, in which namely the ring gear 2 can be rotated relative to the gear 1 for the purpose of converting the machine. For this purpose - starting from the illustration in FIG. 1 - the threaded sleeve 21 is screwed further onto the pin 13. As long as the threaded sleeve 21 and the sleeve 19 do not touch, nothing changes in the non-positive coupling between the ring gear 2 and the gear 1. However, the lever 26 is moved and the electrical switch 31 is thus actuated. As a result, the power supply to the drive of the printing press is interrupted, so that the printing press cannot be started up before the coupling force acting between the ring gear 2 and the gear 1 is reduced.

By further turning the threaded sleeve 21, the compression spring 15 is then stretched over the sleeve 19, the rollers 18 and the disk 17, whereby the pressure lever 9 is relieved until they are finally freely movable. The ring gear 2 can then be adjusted relative to the gear 1 in the required manner. The selected position is finally fixed by turning the threaded sleeve 21 in the opposite direction. Only after the full force of the compression spring 15 on the support areas 12 of the pressure lever 9 is effective is the interruption of the power supply for driving the printing machine canceled again by further turning the threaded sleeve 21.

The device shown in Figures 1 to 3 not only fulfills this safety function, but also enables adjustment with a few simple steps and with little effort. The pressure levers 9 and the thrust bearing 17, 18, 19 designed as a roller bearing essentially contribute to the low expenditure of force.

Fig. 3 shows a plan view of the first embodiment. The pressure levers 9 are only partially visible from the outside through an annular gap between the tensioning disk 7 and the ring gear 2. Otherwise they are shown in dashed lines.

In the exemplary embodiment shown in FIG. 4, a gearwheel 41, which is designed similarly to the first exemplary embodiment, is fastened on the end face on the shaft 4 with the aid of screws 5. The ring gear 2 is also rotatably mounted on an annular shoulder 42 of the gear 41. The clamping disk 43 is not rigidly connected to the gear 41, but is pressed by a plurality of clamping elements 44 distributed around the circumference onto a shoulder 45 of the ring gear 2, which in turn rests on the gear 41 at 46. This ensures a frictional coupling of the ring gear 2 with the gear 41.

The clamping elements 44 each consist of a screw, the head 48 of which is disc-shaped and serves as an abutment for a compression spring 49 composed of disc springs. Corresponding cutouts 50 are provided in the gearwheel 41 for the compression springs 49 and the screw heads 48 of the clamping elements 44. A nut 51 is tightened so far that the compression spring 49 has the required bias. The nut 51 is fixed by a lock nut 52.

To release the coupling between the ring gear 2 and the gear 41, six radial pressure levers 53 are provided, which are inserted into corresponding radial grooves 88 of the tensioning disk 43 and each have a bearing area 54, 55, 56 against the gear 41, the tensioning disk 43 and support a pressure ring 61 arranged centrally in the tensioning disk 43, which together with a roller cage located between the pressure ring 61 and the pressure flange 64 forms an axial thrust bearing.

Because of the high surface pressure caused by the curved support areas 54, 55, 56 of the pressure lever 53, the gearwheel 41 is provided with hardened support plates 57, which are held by screws 58, and the tensioning disk 43 is provided with hardened threaded pins 59. The latter also serve to adjust the pressure levers 53 in the sense of a uniform distribution of the forces to be transmitted by them over the entire circumference of the device.

The axial pressure bearing 61, 64 can be moved in the direction of the pressure lever 53 with a centrally arranged screw 60, which is mounted in a corresponding thread of the tensioning disk 43. The screw 60 can initially cover a path which does not yet exert any pressure on the pressure lever 53, but within which the actuating lever 26 is moved. Before the clutch force is reduced, the drive power supply is switched off. If the screw 60 strikes the pressure flange 64, the latter will rotate with the screw relative to the pressure ring 61. The axial thrust bearing provided with a roller cage ensures that the friction to be overcome for turning the screw 60 essentially consists only of the thread friction of this screw.

In corresponding bores of the clamping disk 43 are circular around the screw 60 a plurality of coil springs 62 are arranged. These are designed so that they exert a certain preload on the thrust bearing 61, 64 even when there is no contact between the screw 60 and the pressure flange 64 and thus hold the pressure lever 53 in a defined position.

FIG. 5 shows a top view of the arrangement according to FIG. 4. Some parts that are not visible per se from a top view are drawn with dashed lines.

Fig. 6 shows a third embodiment in which the pressure levers also serve as spring elements. In this arrangement, the tensioning disk 72 is fixedly connected to a gearwheel 71 in a manner similar to the exemplary embodiment according to FIG. 1. By means of screws 73, the tensioning disk 72 is firmly screwed to the gear 71 and has radial grooves 74 through which pressure levers 75 are guided, which, with their short lever arm formed between the bearing areas 76 and 77, bring about a non-positive coupling of the ring gear 2 with the gear 71 , when - as shown in the figure - the bearing area 78 of the long lever arm is loaded with a corresponding force. This load is based on a screw 79, which is secured with an arrangement 80, which is only shown schematically, to prevent it from being mistaken.

The shaft of the screw 79 is mounted in a sleeve 81 which is provided with an external as well as an internal thread and serves as an adjusting element. The sleeve 81 can be rotated via a hexagon screw head 82. The external thread of this sleeve has a slightly larger pitch than its internal thread with the same direction of pitch. An axial adjustment of the screw 79 by the difference in pitch in the respective adjustment direction of the sleeve is thus achieved per revolution of the sleeve 81.

In a similar manner to the other exemplary embodiments, the sleeve 81 is provided with a circumferential groove 83, in which the lever 26 engages in order to actuate the electrical switch 31.

To limit the path of the sleeve 81, a fixed stop 84 and a counterpart 85 are provided on the sleeve 81.

In each case a pin 86, which is provided with a thread and is screwed into the support plate, is loosely inserted through a bore 87 in each pressure lever 75 and serves to guide the pressure lever 75.

In the position shown in FIG. 6, the electrical switch 31 is closed, so that the machine can be put into operation since the coupling between the ring gear 2 and the gear 71 is closed with the required force. If the relative rotational position of the ring gear 2 is to be adjusted in relation to the gear 71, the sleeve 81 is screwed into the tensioning disk. It travels a relatively large distance, so that the lever 26 and thus the electrical switch 31 are actuated at the beginning of the path. The screw 79 has traveled only a short distance, whereby the resilient pressure levers 75 are somewhat relaxed, but the pressure exerted by them on the ring gear 2 is still sufficient to hold the ring gear securely. Only when the sleeve 81 is turned further are the pressure levers 75 relaxed to such an extent that the ring gear 2 can be rotated on the gear 71.

Claims (14)

1. Device for adjusting a relative rotational position of a gearwheel (1, 41, 71) and a ring gear (2) being coaxially mounted so as to be rotatable on an annular extension (3, 42) of said gearwheel, comprising radially extending pressure levers (9, 53, 75) actuatable in common by an axially adjustable and centrically disposed adjusting element (21, 60, 81) for releasing a spring-biased positive connection of adjoining end faces of said gearwheel and said ring gear by reducing the spring bias acting upon said end faces, characterized in that said pressure levers (9, 53, 75) are loosely disposed between said annular extension (3, 42) and a disc (7, 43, 72), are received in radial grooves (8, 74, 88) formed in said pressure levers and are pivotally braced against respectively said annular extension and said disc at a first contact region (10, 54, 76) located on the outline of a respective pressure lever and between the ends thereof, and that said adjusting element (21, 60, 81) is displaceable within an adjustment travel comprising a first portion in which the spring bias increases from a low value to a value necessary for maintaining the relative rotational position, and a second portion in which the spring bias necessary for maintaining the relative rotational position is at least maintained and in which an electric switch (31) connected to a supply circuit of a drive device can be actuated.

2. Device according to Claim 1, characterized in that said pressure levers (9) have short lever arms between said first contact regions (10) and second contact regions (11) located thereon and long lever arms between said first contact regions (10) and third contact regions (12) also located thereon and are braced against said disc (7) at said first contact regions, that said second contact regions (11) are braced against an end face of said ring gear (2) facing away from said gearwheel (1), that in the region adjacent to the axis of said gearwheel (1) an axially directed force can be applied to said third contact regions (12) by means of a pressure spring (15), and that within said first portion of the adjustment travel said adjusting element (21) performs a movement independent of said pressure spring (15) and loads said pressure spring (15) within said second portion of the adjustment travel.

3. Device according to Claim 2, characterized in that said gearwheel and a shaft carrying said gearwheel form an assembly comprising a centric pin being fixed against rotation, carrying said pressure spring (15) and an axial thrust bearing (17, 18, 19), and featuring a threaded section (20) whereon said adjusting element (21) is mounted.

4. Device according to Claim 2, characterized in that said pressure spring (15) is formed of cup springs.

5. Device according to Claim 2, characterized in that said adjusting element (21, 60, 81) features an annular groove (25, 83) in which an actuating element of a electric switch (31) engages.

6. Device according to Claim 2, characterized in that said adjusting element features a further annular groove (23) in which a stop (24) for limiting the adjustment travel of said adjusting element engages.

7. Device according to Claim 3, characterized in that third contact regions (12) of pressure levers (9) are braced against a diametrically enlarged disc (17) of said axial thrust bearing (17, 18, 19).

8. Device according to Claim 1, characterized in that said ring gear (2) is clamped between said gearwheel (41) and said disc (43) by means of equi-circumferentially arranged springy clamping elements (44, 49), that said pressure levers (53) are braced, at said first contact regions (54) thereof, against an end face of said annular extension (42) of said gearwheel (41), that second contact regions (55) of said pressure levers are braced against said disc (43) in a radially outer region of a respective groove (88), and that third contact regions (56) of said pressure levers are braced against an axial thrust bearing (61, 64) being centrically inserted in said disc and being axially adjustable by means of said adjusting element (60), short lever arms being formed between said first contact regions (54) and said second contact regions (55) of said pressure levers and long lever arms being formed between said first contact regions and said third contact regions (56) of said pressure levers.

9. Device according to Claim 8, characterized in that said adjusting element comprises a bolt (60) threadedly secured in a threaded bore formed in said disc (43), that an end of said bolt (60) engages in a centric bore formed in a pressure flange (64), that said pressure flange (64) extends into a centric recess formed in said disc (43), and that said pressure flange (64) is braced against said third contact regions (56) of said pressure levers (53) at a side of a pressure ring (61) of said axial thrust bearing (61, 64) which faces away from said disc (43).

10. Device according to Claim 8, characterized in that hardened intermediate members (57, 59) are provided at locations of said gearwheel (41) and said disc (43) which contact said pressure levers (53).

11. Device according to Claim 10, characterized in that said intermediate members disposed at said locations of said disc (43) are formed as threaded pins (59).

12. Device according to Claim 1, characterized in that said pressure levers (75) have short lever arms between said first contact regions (76) and second contact regions (77) and have long lever arms between said first contact regions and third contact regions (78) and are braced against said disc at said first contact regions (76) and against said end face of said ring gear (2) facing away from said gearwheel (71) at said second contact regions (77), and that said pressure levers are elastically deformable by application of a force on said third contact regions (78) by means of said adjusting element which is centrically inserted into said disc (72).

13. Device according to Claim 12, characterized in that said adjusting element (81) comprises a sleeve having an external and an internal thread and being mounted in a centric threaded bore formed in said disc (72), that a bolt (79) which is cooperatively connected with said internal thread of said sleeve (81) is axially displaceable yet mounted so as to be fixed against rotation, that said third contact regions (78) of said pressure levers (75) are braced against the contact surface of the head of said bolt (79), and that the respective pitches of said external and said internal thread of said sleeve differ slightly from one another.

14. Device according to anyone of Claim 1 to 13, characterized in that means (24, 84, 85) are provided for limiting the adjustment travel of said adjusting element (21, 81).

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