GB2038440A

GB2038440A - Shaft coupling for, inter alia, rotary printing apparatus

Info

Publication number: GB2038440A
Application number: GB7943017A
Authority: GB
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1978-12-14
Filing date: 1979-12-13
Publication date: 1980-07-23
Also published as: DE2854032A1; GB2038440B; DE2854032C3; FR2444196A1; CH641880A5; DE2854032B2; FR2444196B1

Abstract

A driving device for the drive of rotary printing machinery has a shaft coupling (35) for two shaft ends to be coupled (27,29) in a positive manner when their speeds of rotation are synchronised, the shaft ends (27,29) being connected to operand input shafts (51,53) of gearing (55) sensitive to asynchronism of the shaft ends (27,29). A signal disc (59) having position markings (75,77) is connected to the output shaft (57) of the gearing (55) and indicates or provides an electric signal to a control (83) for the coupling (35) when synchronism of the shaft ends (27,29) occurs. <IMAGE>

Description

SPECIFICATION Shaft coupling for, inter alia, rotary printing apparatus This invention relates to shaft couplings, and is particularly although not exclusively concerned with shaft couplings for use with web-fed rotary printing apparatus.

In the main drive shaft of a web-fed rotary printing press, a number of shaft couplings are usually provided. Such couplings allow, for example, the drive of the feeding mechanism, the cooling mechanism and the folding mechanism, to be disconnected from the printing cylinder drive, and consequently make it possible for the printing mechanism cylinders and also their inking mechanisms to be washed and for the blocks to be inserted when the printing mechanism cylinders are running, yet for the paper path to be stationary, that is without resulting in waste paper. As the main drive shaft usually ensures synchronisation of the individual units of the printing press, it must be ensured that, after each uncoupling, a precisely registration-stable recoupling takes place at the critical points of the printing press, for example, between the printing mechanism and the folding mechanism.A socalled cylinder run-on-coupling is often used for this.

A coupling suited per se therefor is known from German Patent Specification 12 72 935. It comprises two co-axial coupling discs on two shaft ends which are mutually aligned, of which one disc has an axially displaceable index pin and the other a boring which matches this. Another similar coupling according to German Offenlegungsschrift 25 53 768 uses two co-axial toothed discs, one of which is axially displaceable.

A register search pin in toothed disc, which can fall into a corresponding notch in the other toothed disc, likewise permits coupling of the two toothed discs only in a well-defined angular position. In this connection, it would be conceivable in both cases to provide several notches if coupling may take place in several angular positions of a shaft rotation.

These known shaft coupling have the disadvantage (in addition to the extremely undesirable characteristic of being able to be coupled only when stationary), that they only permit between the two shaft ends to be coupled such relative angular positions which are equal to a random number of complete rotations, or, if several notches are provided, which are smaller than a complete rotation. However, frequently, the two shaft ends may only have relative anguiar positions which are in each case greater than a complete shaft rotation. This is the case, for example, with such web-fed rotary printing presses with which the main drive shaft has a higher speed than the units of the printing press which are being driven, so that smaller couplings and other transmission elements can suffice owing to the smaller torsional moment to be transmitted.The main drive shaft then makes for each rotation of the printing cylinder, for example, four rotations, with the result that the known shaft couplings cannot be used at all, as for each cylinder rotation they would offer at least four different coupling possibilities.

The present invention aims to provide a generally improved shaft coupling.

According to the present invention, there is provided a shaft coupling comprising two shaft ends, first means for positively coupling together the shaft ends, and second means for determining the relative angular positions of said shaft ends, which second means comprises a rotary summing gear having two operand input shafts and a result output shaft, means for connecting said input shafts respectively to said shaft ends, and an indicating member arranged to be rotatably driven by said output shaft, the arrangement being such that said indicating member makes exactly one complete revolution for each complete revolution of one of said shaft ends relative to the other.

Advantages of preferred embodiments of the invention are that, after each uncoupling, a registration stable re-coupling from any relative angular position of the two shaft ends may be achieved, and the coupling does not need to be operated in a stationary position. A coupling may be constructed with commercial summing gears, for example, with planetary or sun-and-planet gears, and may be therefore relatively inexpensive.

Ithasthe additional advantage of making a purely mechanical phase comparison and consequently of measuring up to the rough working of practice than alternatives such as, for example, use of an electronic calculator. Furthermore, the existence of a coupling possibility is indicated by the indicating member becoming stationary, with the result that to produce a corresponding electrical signal, no slip rings are required, which could be susceptible to fouling and consequent trouble.

The invention may be carried out in numerous ways. However, certain embodiments thereof will be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows, diagrammatically, a conventional web-fed rotary printing press with shaft couplings; Figure 2 shows, diagrammatically, a shaft coupling in accordance with the invention, for use in an arrangement as shown in Figure 1; Figure 3 shows the coupling of Figure 2 in detail; and Figures 4 and 5 show respectively parts of two further couplings similar to that of Figure 2.

Figure 1 schematically shows a conventional web-fed rotary printing press having a roller windoff device 1, a feeding mechanism 3, several printing mechanisms 5, a drier 7, a cooling mechanism 9 and a folding mechanism 11. The individual printing press units 1 to 11 are driven by a main motor 17 via a longitudinal shaft 1 3 serving as main drive shaft and via a transmission gear 1 5. Roller wind-off device 1 and feeding mechanism 3 and also cooling mechanism 9 are connected to the longitudinal shaft 1 3 via separating shaft couplings 1 9 and 21 respectively, a cylinder run-off coupling 23 being located between the longitudinal shaft 1 3 and the folding mechanism 11, and parts of the folding mechanism 11 being connected to the cylinder run-on coupling 23 via a separating coupling 25.

The shaft couplings 19 to 25 serve to disconnect the printing press units 1 to 11 individually as required. This is necessary, for example, when the cylinders of the printing mechanisms 5 are to run-on when the paper path is stationary, so that the individual blocks can be inserted and the printing mechanism cylinders and also their inking mechanism can be washed without this resulting in any waste paper.

In order to manage with the smallest possible couplings 19 to 25, and other transmission elements, the longitudinal shaft 1 3 is generally operated at a higher speed than the cylinders of the printing mechanisms 5 and the component parts of the folding mechanism 11, a corresponding transmission gear being provided in each case therefor between the longitudinal shaft 13 and each of the printing mechanisms 5 and the folding mechanism 11 respectively. It is customary in this connection for the longitudinal shaft 13 to make four rotations for each cylinder rotation and each (or according to the cylinder coating each second or third respectively) working cycle of the folding mechanism 11, with the result that after each uncoupling, care must be taken in re-coupling that synchronism exists at least between the printing mechanism 5 and the folding mechanism 11.

To this end, in a first embodiment of the invention, the cylinder run-on coupling 23, effectively between the printing mechanisms 5 and the folding mechanism 11, is arranged as shown in Figure 2. The longitudinal shaft 13, driven by the main motor 1 7 via the transmission gear 15, has two shaft ends 27 and 29 which are capable of being coupled together in a positive, formlocked manner, with the aid of two front-toothed toothed discs 31 and 33 of an electromagnetic coupling 35. The right hand (in Figure 2) toothed disc 33 is axially displaceable for this purpose, yet iswkeyed to the shaft end 29 for rotation therewith, and can engage with the toothed disc 31 under the action of a magnet coil 37.

Two belt pullies 39 and 41 are arranged on the shaft ends 27 and 29, and are connected via toothed belts 43 and 45 to two belt pullies 47 and 49 on two operand input shafts 51 and 53 of a rotary summing gear 55. A signal disc 59, adjustable in its angular position, is located on a result output shaft 57 of the summing gear 55.

The signal disc 59 serves to indicate a relative angular position of the two shaft ends 27 and 29.

which is appropriate for coupling the toothed discs 31 and 33.

In the embodiment shown in Figure 2 by way of example, the summing gear 55 is formed as a double planetary gear having two sun wheels 61 and 63 secured to the input shafts 51 and 53, two corresponding internally toothed annuli 65 and 67, and two planet pinions 71 and 73 which are capable of rotating freely on a rotating planet carrier 69, and each engage with a respective sun wheel and annulus (61, 65 and 63, 67 respectively).

One of the two annuli 65 and 67 (the right annulus 67 in the drawing), is secured against rotation, and the other annulus 65 is connected to the signal disc 59. Thus, the annulus 65 and hence also the signal disc 59 (in the same way as the outer rim 67) is stationary if the two sun wheels 61 and 63 and hence also the two shaft ends 27 and 29 rotate at exactly the same speed.

In this respect, the signal disc 59 occupies a prescibed zero position if the two shaft ends 27 and 29 also have a prescribed angular position relative to one another.

The entire transmission between the shaft ends 27 and 29 and the signal disc 59, that is the product of the transmission within the planetary gear with that of the belt pullies 39,47 and 41, 49 respectively, is now selected to be equal to the transmission between the longitudinal shaft 13 and the cylinders of the printing mechanisms 5 and the component parts of the folding mechanism 11 respectively. This means that the signal disc 59 rotates precisely with the cylinder speed when the shaft end 29 which is connected to the folding mechanism 11 is stationary, or with (produced, for example, by an auxiliary motor in the folding mechanism 11) folding mechanism speed only in the opposite direction thereto when the shaft end 27 is fixed as a result of the main motor 1 7 stopping.As a result, the signal disc 59 has completed precisely one rotation when the printing mechanism cylinder shaft has also rotated once (relative to the stationary folding mechanism shaft), or when the folding mechanism shaft has rotated once (relative to the printing mechanism shaft), and consequently the printing mechanism shaft and folding mechanism shaft are again in the synchronism with one another. In the example chosen, the longitudinal shaft 1 3 has completed four rotations for every rotation of the printing mechanism cylinder shaft or of the folding mechanism shaft.

The signal disc 59 at the output of the summing gear 55 thus makes two things possible.

As a result of the symmetrical construction of the summing gear 55 and of securing the one annulus 67, it indicates by stopping in the zero position both that the speeds at its two inputs coincide (and hence also the speeds of the printing mechanism cylinder-- and folding mechanism shaft), and that, as a result of the suitably selected transmission, the angular positions of the printing mechanism cylinder shaft and the folding mechanism shaft coincide, hence giving precise synchronism between the printing mechanism cylinder shaft and folding mechanism shaft.

The signal disc 59 can be used in a simple manner to give an optical indication to an operator (by stopping in its zero position) of the appropriate moment for coupling, with the result that the operator can trigger coupling manually. In a particularly advantageous manner, however, the cylinder run-on coupling can also be used to trigger the coupling process automatically. In this respect, the signal disc 59 has in the proximity of its periphery two markings in the form of electrical damping elements 75 and 77 which are sensed by two sensors in the form of so-called initiators 79 and 81.The initiators 79 and 81 are supplied with a high frequency alternating current from a logic unit 83 via supply lines 85 and 87 and, when in the vicinity of the damping elements 75 and 77, are damped by these as a result of transfer of energy, which is communicated to the logic unit 83 again via the supply lines 85 and 87.

As soon as the initiators 79 and 81 have detected the damping elements 75 and 77 and consequently have determined the zero position of the signal disc 59, the logic unit 83 triggers the magnetic coupling 35 via a supply line 89 by exciting its magnet coil 37, with the result that the toothed discs 31 and 33 engage with one another.

At the same time, the logic unit 83 acts on a control unit 93 at a three-phase supply network, to reduce the speed of the main motor 17.

The arrangement is such that the damping element 75 has a greater range than the damping element 77, with the result that the initiator 79 responds before the initiator 81. The initiator 79 causes the main motor 1 7 to be switched over into a so-called crawl when it is acted upon by the damping element 75, and only then does the other initiator 81 become operative. As soon as the latter is damped by its damping element 77, the coupling process is triggered and, advantageously, shortly before this, the speed of the main motor 1 7 is further reduced until it becomes a step-bystep drive.

To indicate whether the coupling process triggered by the logic unit 83 by way of controlling the initiator 81 has in fact taken place, there is a further initiator 95 which is mounted on the periphery of the axially movable toothed disc 33 and which is damped either by the latter or by an additionally mounted damping element when the toothed disc 33 has been moved axially into engagement with the toothed disc 31. The initiator 95 is connected via a supply line 97 to the logic unit 83, and indicates via the latter the respective coupling state to the operator at a control desk 99. If required, a further coupling attempt can also be triggered by the initiator 95.

In Figure 3, the cylinder run-on coupling 23, enclosed by two boxes in broken lines in Figure 2, is shown in detail. There are mounted on the two shaft ends 27 and 29, two coupling halves 101 and 103 which carry respectively on their front ends the fixed front-toothed disc 31 and the axially movable front-toothed disc 33 with toothing 105. The toothed disc 33 can, under the action of the magnet coil 37 of the magnetic coupling 35, be displaced in axial toothed tracks 107 until it engages in the fixed toothed disc 31.

The magnet coil 37 is held in a stationary part 109 of the magnetic coupling 35.

The summing gear 55, with the sun wheels 61 and 63, the outer annuli 65 and 67 and the planet carrier 69 with the planet pinions 71 and 73 (of which in each case two of four or six present are shown) is connected via the belt pullies 39, 47 and 41, 49 and also the two toothed belts 43 and 45 to the two coupling halves 101 and 103, and via these to the two shaft ends 27 and 29.

The fixed annulus 67 is formed by a portion of a stationary housing 111 of the summing gear 55.

The signal disc 59 is connected to the movable annulus 65 via the output shaft 57. It carried at its periphery the damping elements 75 and 77 which co-operates with the two initiators 79 and 81 for indicating the coupling position, which are secured to the housing 111.

The third initiator 95 for indicating the coupling state is arranged in an axial direction on the periphery of the axially movable toothed disc 33 such that it is damped by the toothed disc 33 when the latter has failen into the toothed disc 31.

The arrangement shown in Figure 3 has the advantage of being particularly compact, as the planetary summing gear 55 allows the required ratio (of 1:4 in the present case) to be realised.in the smallest possible space and, as a gear of twin construction on both input shafts 51 and 53, permits the same transmission ratio (of 1 :1) and hence space-saving transmission gears.

Figure 4 shows a variation in which, with an otherwise similar construction, the summing gear 55 is constructed as a simple planetary gear 11 3.

It has only one sun wheel 11 5, one movable outer annulus 11 7 and one planet pinion 121 mounted on a rotating planet carrier 119. Its sun wheel 11 5 is connected to the belt pulley 47 (and via this to the shaft end 27), and its carrier 119 is connected to the belt pulley 49 (and via this to the shaft end 29). The annulus 117 carries the signal disc 59 with its damping elements 75 and 77 which act on the initiators 79 and 81.

The planetary gear 113 is simpler in construction than the summing gear 55, yet requires more space, as owing to the different ratio between the sun wheel 11 5 and annulus 117 on the one hand and between the carrier 119 and annulus 11 7 on the other hand, it requires different ratios at its input shafts 51 and 53 and hence one additional transmission gear to at least one input shaft. Furthermore, owing to the change of direction occurring, an additional reversing gear is necessary at one input shaft if the two shaft ends 27 and 29 are to rotate in the same direction.

Figure 5 shows a further variation in which once again only the summing gear 55 is.

constructed differently, the remainder of the construction being as shown in Figure 2. Here, the summing gear consists of a planetary gear 123 having two sun wheels 125 and 127 and a pair 1 31 of planet pinions guided on a rotating planet carrier 129, the planet pinions 133 and 135 of which are interconnected such that they rotate together, and have different diameters. One of the two sun wheels 125 and 127 (the right sun wheel 127 in the drawing), is connected to the belt pulley 47 (and via this to the shaft end 27) and the carrier 129 is connected to the belt pulley 49 (and via this to the shaft end 29). The other sun wheel 1 25 carries the signal disc 59 with its -damping elements 75 and 77 which act on the initiators 79 and 81.

The planetary gear 123 is also very simple in construction. It permits relatively few different ratios at its output shafts 51 and 53 and hence a relatively small space requirement for an additional transmission gear to at least one input shaft, unless a different direction of rotation at the two shaft ends 27 and 29 or an additional reversing gear has to be takein into consideration.

In the embodiments described above, owing to the relatively great torsional movement to be transmitted, the shaft coupling comprises a particular magnetic coupling 35 with two toothed discs 31 and 33 which engage in one another in a form-locked manner. However, it is also conceivable to couple the two shaft ends 27 and 29 in an extremely simple manner in that, when the signal disc 59 arrives in the zero position, which, as before, is indicated to the logic unit 83 by the initiators 79 and 81, the signal disc 59 or another part mounted on the output shaft 57 of the summing gear 55 (or of the planetary gear 113 and 123 respectively) is fixed such that it is secure against rotation, for example, by being connected in a form-locked manner to a housing of the summing gear, with the result that a synchronous run-on is forced in this way. This procedure has the advantage of a reduced space requirement, but demands a more marked dimensioning of the summing gear which then, in any case, is more expensive.

In variants of the illustrated arrangement, the signal disc 59 can be connected to the output shaft 57 via a transmission gear, and/or its angular position relative to the shaft 57 may be selectively variable.

Claims

1. A shaft coupling comprising two shaft ends, first means for positively coupling together the shaft ends, and second means for determining the relative angular positions of said shaft ends, which second means comprises a rotary summing gear having two operand input shafts and a result output shaft, means for connecting said input shafts respectively to said shaft ends, and an indicating member arranged to be rotatably driven by said output shaft, the arrangement being such that said indicating member makes exactly one complete revolution for each complete revolution of one of said shaft ends relative to the other.

2. A shaft coupling according to claim 1, wherein said indicating member comprises a disc.

3. A shaft coupling according to claim 1 or 2, wherein said shaft ends are connected indirectly to said input shafts.

4. A shaft coupling according to claim 3, wherein at least one of said shaft ends is connected to its respective input shaft via a transmission gear.

5. A shaft coupling according to claim 3 or 4, wherein at least one of said shaft ends is connected to its respective input shaft via a reversing gear.

6. A shaft coupling according to any preceding claim, wherein said output shaft is connected to said indicating member via a transmission gear.

7. A shaft coupling according to any preceding claim wherein the summing gear is a planetary gear.

8. A shaft coupling according to claim 7, wherein the planetary gear comprises a sun wheel, an internally toothed annulus, and a planet carrier carrying at least one planet pinion which engages with the sun wheel and the annulus, one of said input shafts drives the sun wheel, the.other input shaft drives said carrier, and the indicating member is connected to the annulus.

9. A shaft coupling according to claim 7, wherein the planetary gear comprises two sun wheels and a planet carrier carrying at least one pair of planet pinions engaging with both sun wheels, the two planet pinions of the or each pair being interconnected such that they rotate together, one of said input shaft drives one sun wheel, the other input shaft drives said carrier, and the indicating member is connected to the other sun wheel.

10. A shaft coupling according to claim 7, wherein the planetary gear comprises two sun wheels, two internally toothed annuli and a planet carrier carrying planet pinions which each engage with a respective sun wheel and annulus, each input shaft drives a respective sun wheel, the indicating member is connected to one of the annuli, and the other annulus is secured in a stationary housing of the shaft coupling such that it is incapable of rotation.

11. A shaft coupling according to any preceding claim, wherein said first means comprises a device which, when said shaft ends are coupled, is triggered to secure the output shaft of the summing gear in a stationary housing of the shaft coupling such that it is secure against rotation.

12. A shaft coupling according to any preceding claim, wherein said first means comprises two toothed discs which are secured respectively in a co-axial manner on the two shaft ends for rotation therewith, at least one of said toothed discs being axially displaceable.

13. A shaft coupling according to any preceding claim, comprising a control device having a first stationary sensor which is adapted to sense a first part on or of the indicating member, the control device being arranged to control operation of said first means.

14. A shaft coupling according to claim 13, wherein the control device has a second stationary sensor which is adapted to sense a second part on or of the indicating member, thereby to render the first sensor operative and to output a speed reduction signal for at least one drive motor for one of said shaft ends, by way of the control device.

1 5. A shaft coupling according to claim 13 or 14, wherein the control device has a third stationary sensor which is adapted to sense a third part of said first means when said shaft ends are positively coupled, thereby to output a speed increase signal for at least one drive motor for one of said shaft ends by way of the control device.

1 6. A shaft coupling according to any preceding claim, wherein the relative angular position of the indicating member is adjustable relative to the output shaft of the summing gear.

1 7. A shaft coupling according to any preceding claim, including a drive motor for at least one of said shaft ends.

1 8. A shaft coupling substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings.

1 9. A shaft coupling substantially as hereinbefore described with reference to Figures 2 and 3 as modified by Figure 4 or 5 of the accompanying drawings.

20. Web-fed rotary printing apparatus having at least one shaft coupling according to any preceding claim.