GB1580673A - Cutting device for rod-shaped objects - Google Patents

Description

(54) A CUTTING DEVICE FOR ROD-SHAPED OBJECTS (71) We, SKODA, oborovy podnik, a Czechoslovak Body Corporate of Plzen, Czechoslovakia, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: The invention relates to a device for an automatic shift of cutting tools of a two-tool cutting-off machine for cigarettes or filter rods, and for stopping the machine when the tools are consumed.

The cigarette production is carried out so that an infinite rod of tobacco, enveloped by a cigarette paper and shaped in a circular cross-section of a determined and constant diameter, is manufactured in a cigarette machine after previous production process.

This inifinite rod is cut in individual cigarettes the accurate length of which as well as a smooth cut, normal to the longitudinal axis of a cigarette, is very important. That is why a cigarette machine is provided with a cutting-off device. The function of this device affects the output of the machine and the quality of cigarettes which depends on the speed of the cutting-off tool revolutions, and upon the quality of the tool edge and upon its sharpening. The tools are reduced in size by continual sharpening which is why they must be continuously shifted out.

Known cutting-off devices are mostly provided with one tool, the revolutions of which have been increasing all the time according to the increasing requests concerning outputs of cigarette machines. This is why two-tool cutting-off devices are now used, and so the tool revolutions can be reduced. There is another problem, that the shift-out of tools whether for sharpening or cutting should be reduced. The known cutting-off devices are provided with gear mechanisms for tools to be shifted out.

These are situated directly in a tool head of the cutting-off device which causes imbalance in the tool head. Furthermore placing the gear mechanism in a plane at an angle to the axis of the cutting-off device, is also disadvantageous.

According to the invention there is provided a cutting device in a cigarette making machine, arranged to be driven by the machine, comprising a tool head fixed on one end of a hollow shaft, the tool head accommodating two cutting tools, a mechanism arranged for the outward displacement of each tool, and a mechanism arranged for signalling the outer limit position of the tools and for stopping the machine, the other end of the hollow shaft being fixed to a plate on which a drive for the mechanism for the displacement of the tools is situated.The tool head may be provided with a toothed pinion which engages two racks, in one of which there is a recess placed opposite a top of a signalling mechanism, the two racks are fixed to pins that are in contact with cuts-out of tools placed on changeable bevelled pads and on the outer surfaces of tools there are elastically situated holding-down plates. The tooth pinion of the tool head is preferably slidingly seated on one end of a small shaft runningly fit in the hollow shaft, and the other end of which is adapted for a drive transmission from a driving mechanism fixed on the plate. On the tool head there may be arranged a mechanism for signalling a limit position of tools which consists of a stop fixed on to a one-arm lever to the loose end of which a stop plate or reflexing disc is fixed and an electromagnet with a time relay is applied for a drive of shifting mechanism.

On one of the parts for a drive of a shifting mechanism of tools there is situated a control element of timed swings.

A separation of the shifting mechanism from the transmission mechanism and the driving mechanism is an advantage of the device according to the invention. There are other advantages, viz. a simple design, an easy production of parts, an easy change of tool inclination by exchangeable pads to be able to cut differently long rod objects, e.g.

cigarettes, one common driving mechanism for both tools, a possibility to throw the driving pinion out of the driving racks which makes the tool changing easier, a signalling of tool consumption by stopping the machine, a possibility to apply longer tools with respect to a free space inside the tool head.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a front elevation of the device, partly in section, Figure 2 is a side elevation of the device, partly in section Figure 3 is a plan view of the tool head in partial section, and Figure 4 shows the tool head in a view in the direction of the arrow "S" in Figure 1.

As is shown in Figures 1 and 2, the device comprises a toothed wheel 1 connected by means of gearing or hinged mechanisms to the main shaft of the cigarette making machine. The toothed wheel 1 is fixed on a hollow shaft 2, one end of which carries a tool head 3 and the other end carries a plate 4, on which there is arranged mechanism for the displacement of cutting tools 5 and a counter-weight 6. Two tools 5 are situated on replaceable slanted pads 7 in the tool head 3 which is trough-shaped. Upper surfaces of the tools 5 are in contact with holding-down plates 8 to which there are connected, by means of pins 9, adapters slidably mounted in yokes 10 fixed on to the tool head 3. Compression springs 11 surround pins 9 of the adapter and act between the plates 8 and yokes 10. The inner ends of the tools 5 are provided with cut-outs 12 (Figure 3).Pins 13 fixed to racks 14 engaging a pinion 15 are in contact with the cut-outs 12. The pinion 15 is slidably connected, by means of a key 16, to a shaft 17 (Figure 1) which is rotatably mounted inside the hollow shaft 2. A compression spring 18 is situated between a stepped end of a shaft 17 and a hub of the pinion 15. The other end of the shaft 17 is formed by a worm wheel 19 which engages a worm 20 rotatably mounted in a bearing 21 fixed on to the plate 4. A ratchet wheel 22 is fixed to the worm 20. A pawl 23, swingably connected to one arm of a bell-crank lever 25 by means of a pivot 24, co-operates with the ratched wheel 22 in known manner. One end of a tension spring 26 is attached to the pawl 23 and the other to the said one arm of the lever 25, the latter being pivotably mounted on a pin 27 fixed to the bearing 21 to which a stop 28 and a pivot 46 of a counterpawl 47 are fixed.The end of the other arm of the lever 25 is connected by means of a tension spring 29 to the plate 4.

In the rack 14 there is a recess 30 (Figure 3) in which a stop 31 of a signalling mechanism is situated. The signalling mechanism includes a one-arm lever 32 (Figure 4) swingably seated on a pivot 33 the lever 32 being fixed to the tool head 3. The stop 31 which is fixed to a screen 34 or, alternatively, to a reflexing disc 35, is fixed on to the one-arm lever 32 which is connected to the tool head 3 by means of a tension spring 36. A free end of a push-down lever 38 pivotably mounted on a pivot 39 is situated in the axis of the tool head 3 over a projection 37 (Figure 4) of the two-arm lever 25. The pivot 39 is fixed on to a frame of the machine. An arm of the push-down lever 38 is swingably connected by means of a pin 40 to a pull rod 41 which is swingably connected to a core of an electromagnet 43 by means of a pin 42.An inductive static switch 44 (Figure 4) operated by screen 34 or alternatively a light ray is arranged in the circular path of the screen 34, or, alternatively of the reflexing disc 35.

The drive of the hollow shaft 2 with the tool head 3 is derived from the main shaft of the machine by means of gearing or hinging mechanisms.

A time relay connects in a set-up interval the electromagnet 43 which pulls up the push-down lever 38 by drawing-in the core, the loose end of the push-down lever 38 strikes - in the axis of rotation of the hollow shaft 2 - against the projection 37 of the lever 25 which swings and its swing is transmitted to the pawl 23, the pawl 23 swings over the next tooth of the ratchet wheel 22 and catches it by the tension of the spring 26. The contact of the end of the push-down lever 38 and projection 37 of the lever 25 having been over, the pawl 23 turns the ratchet wheel 22 by the tension of the spring 29 and the rotation stop is obviated by a strike of the lever 25 against the stop 28. The ratchet wheel 22 is locked against a reverse revolution by means of the counterpawl 47. The worm 20 is turned a little together with the ratchet wheel 22. The worm 20 engages the worm wheel 19 which causes a small turning of the shaft 17 with the pinion 15 which engages the racks 14, and in this way the tools 5 are shifted in the direction out from the axis of rotation. The feeding of tools continues until the recess 30 of the rack shifts the stop 31 as well as the screen 34, or alternatively the reflexing disc 35, the screen 34 enters the recess of the switch 44 or alternatively the reflexing disc 35 reflexes a light ray.

The push-down lever 38 and the feeding of the tools 5 may be operated alternatively by hand. For this hand operation there is connected a push button 45 to the pushdown lever 38.

In order to remove the tools 5 from the head 3, the holding-down plates 8 are lifted and this releases the tools 5. In order to fit new tools the pinion 15 is pulled out, thus compressing spring 18 and the pinion 15 disengaged from the rack 14 is disconnected, so that - by means of springs (not shown) - the racks 14 return to their initial positions and stop 31 is also loosened and the tension spring 36 returns the one-arm lever 32 and with it also the screen 34 or the reflexing disc 35 into the deflected position.

The pinion 15 re-engages the racks 14 by releasing the pulled-out pinion 15 acted on by the compression spring 18. When new tools 5 are slid in the tool head 3, the machine is ready to be put again into operation. The transmission mechanism is statically balanced by means of the counterweight 6, the tool head 3 being symmetrical.

WHAT WE CLAIM IS: 1. A cutting device in a cigarette making machine arranged to be driven by the machine, comprising a tool head fixed on one end of a hollow shaft, the tool head accommodating two cutting tools, a mechanism arranged for the outward displacement of each tool, and a mechanism arranged for signalling the outer limit position of the tools and for stopping the machine, the other end of the hollow shaft being fixed to a plate on which a drive for the mechanism for the displacement of the tools is situated.

2. A device according to Claim 1, wherein the tool head is provided with a pinion which engages wtih two racks in one of which there is a recess positioned opposite a stop of a signalling mechanism, the two racks being fixed to pins that are arranged to be in contact with cut-outs of the tools placed on replaceable slanted pads, and on the outer surfaces of the tools there are resiliently arranged holding-down elements.

3. A device according to Claim 2, wherein the pinion of the tool head is slidably seated on one end of a shaft rotatably mounted in the hollow shaft, and the other end of which is adapted for a drive transmission from a driving mechanism fixed on the plate.

4. A device according to Claims 1 or 2 wherein on the tool head there is arranged a mechanism for signalling a limit position of the tools which includes a stop fixed on to a one-arm lever to the loose end of which a screen or reflexing disc is fixed, an electromagnet with a time relay being used to drive the displacement mechanism.

5. A device according to Claim 1 or 3, wherein on one of the parts for driving the mechanism for the displacement of the tools there is arranged a projection in the axis of rotation of the hollow shaft, a time control element being situated arranged to engage the projection.

6. A cutting device for rod-shaped objects substantially as herein described with reference to and as shown in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. connected a push button 45 to the pushdown lever 38. In order to remove the tools 5 from the head 3, the holding-down plates 8 are lifted and this releases the tools 5. In order to fit new tools the pinion 15 is pulled out, thus compressing spring 18 and the pinion 15 disengaged from the rack 14 is disconnected, so that - by means of springs (not shown) - the racks 14 return to their initial positions and stop 31 is also loosened and the tension spring 36 returns the one-arm lever 32 and with it also the screen 34 or the reflexing disc 35 into the deflected position. The pinion 15 re-engages the racks 14 by releasing the pulled-out pinion 15 acted on by the compression spring 18. When new tools 5 are slid in the tool head 3, the machine is ready to be put again into operation. The transmission mechanism is statically balanced by means of the counterweight 6, the tool head 3 being symmetrical. WHAT WE CLAIM IS:

1. A cutting device in a cigarette making machine arranged to be driven by the machine, comprising a tool head fixed on one end of a hollow shaft, the tool head accommodating two cutting tools, a mechanism arranged for the outward displacement of each tool, and a mechanism arranged for signalling the outer limit position of the tools and for stopping the machine, the other end of the hollow shaft being fixed to a plate on which a drive for the mechanism for the displacement of the tools is situated.

2. A device according to Claim 1, wherein the tool head is provided with a pinion which engages wtih two racks in one of which there is a recess positioned opposite a stop of a signalling mechanism, the two racks being fixed to pins that are arranged to be in contact with cut-outs of the tools placed on replaceable slanted pads, and on the outer surfaces of the tools there are resiliently arranged holding-down elements.

3. A device according to Claim 2, wherein the pinion of the tool head is slidably seated on one end of a shaft rotatably mounted in the hollow shaft, and the other end of which is adapted for a drive transmission from a driving mechanism fixed on the plate.

4. A device according to Claims 1 or 2 wherein on the tool head there is arranged a mechanism for signalling a limit position of the tools which includes a stop fixed on to a one-arm lever to the loose end of which a screen or reflexing disc is fixed, an electromagnet with a time relay being used to drive the displacement mechanism.

5. A device according to Claim 1 or 3, wherein on one of the parts for driving the mechanism for the displacement of the tools there is arranged a projection in the axis of rotation of the hollow shaft, a time control element being situated arranged to engage the projection.

6. A cutting device for rod-shaped objects substantially as herein described with reference to and as shown in the accompanying drawings.