GB1601603A

GB1601603A - Roller assembly accessories for printing machines

Info

Publication number: GB1601603A
Application number: GB1462778A
Authority: GB
Original assignee: ARTHURS J
Current assignee: ARTHURS J
Priority date: 1978-04-13
Filing date: 1978-04-13
Publication date: 1981-11-04

Description

(54) IMPROVEMENTS IN OR RELATING TO ROLLER ASSEMBLY ACCESSORIES FOR PRINTING MACHINES (71) I, JOHN ARTHURS, of 286 Park Road, London N8 8JY, of British nationality do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement :- This invention relates to a roller assembly forming an accessory for a printing machine.

Printing machines having different numbers of inking rollers are known. The greater the number of inking rollers, the greater is the density of ink that can be deposited on to a print. It is also known to provide an accessory in the form of a roller assembly having at least one inking roller, for mounting on an existing printing machine, whereby the inking capacity of the printing machine can be increased. This has particular application where the increased inking capacity is only required for a proportion of the total output of the machine. The roller assembly accessory provides only the extra rollers, since the inking supply of the printing machine itself is arranged to provide the ink for the additional rollers. The roller assembly comprises a frame having a pair of side plates which are recessed so as to receive a tie bar of the printing carriage of the machine, and the roller assembly is clamped on to this tie bar with at least one of the accessory rollers in contact with at least one of the printing rollers of the machine. Such an assembly, however, suffers from the disadvantage that the interconnection between the roller assembly and the tie bar of the printing machine is not very rigid.

It is an object of the present invention to provide as an accessory for a printing machine a roller assembly which can be particularly rigidly supported on a printing machine.

In accordance with the present invention there is provided a roller assembly accessory for a printing machine the accessory comprising a frame having a pair of side plates, an inking roller carried by the frame, and means for securing the roller assembly on a printing machine such that said inking roller engages a printing roller of the machine, wherein said securing means comprises clamping means for clamping the assembly on to a frame of the printing machine, the clamping means being provided in conjunction with each side plate and acting along a first axis parallel to the axis of the inking roller, and auxiliary fastening means associated with each side plate and positioned spaced from the clamping means on a second axis parallel to said axis of the inking roller, the auxiliary fastening means preventing rotation of the accessory about said first axis and incorporating a positive gripping element in the connection between the said two frames.

Conveniently, the auxiliary fastening means comprises a screw-threaded arrangement which interconnects the roller assembly and the printing machine and which can be arranged to replace a threaded support member that already exists within the printing carriage of the printing machine.

The increased rigidity of the mounting of the roller assembly on the printing machine provided by the present invention allows a simplification in the construction of the roller assembly itself, whereby it does not need to be inherently so rigid.

A roller assembly accessory for a printing machine, in accordance with the present invention, will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the roller assembly; Figure 2a and 2b show a screw-threaded connecting member of the roller assembly; Figures 3a and 3b show a further embody ment of a screw-threaded connecting member; Figure 4a is a plan view of an alternative roller assembly; Figure 4b is a part-view showing the roller assembly of Figure 4a mounted on a printing machine; and Figures 5a and 5b show a screw-threaded connecting member used in the embodiment of Figure 4.

Referring to Figures 1 and 2, the roller assembly comprises a frame 2 having side plates 4 and 6 spaced apart by a single cylindrical tie bar 8. The frame 2 has four inking rollers 10, 12, 14 and 16 rotatably supported therein between the side plates 4 and 6. The inking roller 16 is fixed to the frame 2 by quick-release clamps 18 and 20.

The roller assembly is arranged to be mounted on to the printing carriage of a printing machine, and to this end, the side plates 4 and 6 are provided with open-ended slots 22 and 24 respectively to receive a tie bar of the printing machine frame carriage. Clearly, the shape and positioning of the recesses will be chosen in dependence on the particular construction of the printing machine, and the roller assembly shown in Figure 1 is particularly suited for mounting on the 'Rotaprint' (Registered Trade Mark) R95/2C (Second Head) printing machine.

Thus, the slots 22 and 24 are substantially semicircular at their closed ends, and the clamping is provided by closure bars 26 and 28 respectively held in place by threaded nuts 30. When clamped in position on the printing machine, the inking rollers 10, 12, 14 and 16 engage with printing rollers of the machine.

In this way, the roller assembly is secured to the printing machine by clamping about an axis.

Any weakening of the clamping action gives rise to the possibility of the entire assembly rotating about that axis. The side plates 4 and 6 are accordingly provided with further means for securing the roller assembly to the printing machine. As shown in Figures 1 and 2, this further means comprises a pair of bolts 32, 34 which project outwardly from the side plates 4 and 6 respectively substantially parallel with the axes of the assembly inking rollers. As can be seen from Figure 2, the bolts 32 and 34, which are identical, have a screw thread at each end whereby the bolts act as interconnecting members between the frame 2 of the roller assembly and the frame of the printing carriage. The bolts 32 and 34 can conveniently be arranged to engage with existing tapped holes in the frame of the printing machine and to replace bolts already therein. In the particular application to the 'Rotaprint' (R.T.M.) R95/2C printing machine, the bolts 32 and 34 have a slot substantially half way along their length that is arranged to receive a spring that forms a part of the original machine and which is otherwise attached to the bolt in the existing tapped hole of the machine frame.

Thus, the roller assembly is securely fixed to the frame of the printing machine at two locations on each side thereof and does not require any additional attachment extensions or drilling of holes in the frame of the machine.

Furthermore, since the side plates 2 and 4 are rigidly clamped to the machine frame, only a single tie bar 8 is required on the assembly itself.

It will be appreciated that the length of the shank 38 of the bolts will be chosen in dependence upon the particular application of the roller assembly, and that the threaded end will also be similarly selected. For example, where the spacing of the side plates of the assembly from the frame of the printing machine is required to be less than that of which the side plate and positioned spaced from the clamping means on a second axis parallel to said assembly of Figure 1 is produced, bolts as shown in Figure 3 may be used in place of the bolts 32 and 34. The bolt 40 of Figure 3 is externally-threaded at one end 42, and at the other end is threaded internally so as conveniently to engage a projecting externallythreaded member of a printing machine. A bolt such as shown in Figure 3 finds particular application in attaching a roller assembly that is otherwise in accordance with Figure 1 to the following machines, for example, 'Rotaprint' (R.T.M) machines R30/90, R30/95, R40/80, R20 and R95/2C (Main Head).

It will be appreciated that the screw-threaded arrangement of securing a roller assembly to a printing machine may be used with a roller assembly having a fewer or greater number of inking rollers than is shown in Figure 1.

The roller assembly of Figures 4 and 5 comprises two inking rollers 60 and 62 which are rotatably mounted in side plates 64 and 66 of the assembly frame. This particular roller assembly is designed for mounting on a 'Multilith' (Registered Trademark) printing machine, which has an L-shaped side frame member 68 (Figure 4b). The roller assembly is clamped to a tie bar of the printing machine in a manner corresponding to that of the previous embodiment. In addition to this, the side plates 64 and 66 receive connecting members 69, only one of which is shown in Figure 4b, therein for securement to the printing machine frame 68. As can be seen in more detail in Figure 5, the connecting member 69 has a projection 70 at one end thereof which projects inwardly through the side frame of the roller assembly and is retained in place by a circlip 72 that engages a circumferential recess 74 in the projection 70. At its other end, the connecting member 69 is bifurcated, and one of the arms has two threaded holes 76 tapped therein so as to receive grub screws 78 which are tightened on to one arm of the Lshaped member of the side frame 68 of the printing machine. In this way, the roller assembly can be secured by screw-threaded means to the frame of the printing machine so as to minimise the risk of movement of the frame of the assembly about its clamping attachment to the printing machine tie bar.

Claims

WHAT I CLAIM IS:

1. A roller assembly accessory for a printing machine, the accessory comprising a frame having a pair of side plates, an inking roller carried by the frame, and means for securing the roller assembly on a printing machine such that said inking roller engages a printing roller of the machine, wherein said securing means comprises clamping means for clamping the assembly on to a frame of the printing machine, the clamping means being provided in conjunction with each side plate and acting along a first axis parallel to the axis of the inking roller, and auxiliary fastening means associated with each axis of the inking roller, the auxiliary fastening means preventing rotation of the accessory about said first axis and incorporating a positive gripping element in the connection between the said two frames.

2. A roller assembly according to claim 1, wherein the auxiliary fastening means comprises at least one threaded member associated with each side plate and extending parallel to said axis of the inking roller.

3. A roller assembly according to claim 1 or 2, wherein the auxiliary fastening means comprises at least one externally-threaded member associated with each side plate for engaging a complementarily-threaded hole in the frame of the printing machine.

4. A roller assembly according to claim 1 or 2, wherein the auxiliary fastening means comprises at least one internally-threaded member associated with each side plate for receiving a complementarily-threaded projection of the frame of the printing machine.

5. A roller assembly according to any preceding claim, wherein the auxiliary fastening means comprises a screw-threaded member mounted in or forming part of each side plate.

6. A roller assembly according to claim 1, wherein the auxiliary fastening means comprises, for each side plate, a connecting member extending through the side plate, the connecting member on the inside of the side plate carrying retaining means to prevent its axial withdrawal from the side plate, and on the outside of the side plate having a screw-threaded aperture for receiving a screw to clampingly secure the connecting member to a mounting member of the printing machine.

7. A roller assembly according to any preceding claim, wherein the clamping means comprises an openended recess in each side plate and a closure bar for closing the recess and clamping the accessory to a tie bar of the printing machine.

8. A roller assembly according to any preceding claim, comprising at least one further roller.

9. A roller assembly according to any preceding claim, comprising at least one further releasably-mounted roller.

10. A roller assembly accessory for a printing machine substantially as hereinbefore described with reference to the accompanying drawings.

11. A printing machine having secured thereto a roller assembly accessory in accordance with any preceding claim.