GB2335349A

GB2335349A - Cutting machine.

Info

Publication number: GB2335349A
Application number: GB9904309A
Authority: GB
Inventors: Jens Schindler
Original assignee: Schindler & Wagner KG
Current assignee: Schindler & Wagner KG
Priority date: 1998-03-17
Filing date: 1999-02-25
Publication date: 1999-09-22
Anticipated expiration: 2019-02-25
Also published as: GB9904309D0; GB2335349B; DE19811418B4; DE19811418A1

Abstract

In a collet for cutting machines, which cooperates with the end of a product loaf which is to be cut, only a single double-action operating cylinder (56) is provided for moving claw elements (34) and a release plate (46). This acts with one of its ends upon the claw arrangement (34), with its other end upon the release plate (46). Abutments (16; 12, 14) limit the path of the claw elements (34) and the release plate (46) and thus allow for the use of stroke sections of the operating cylinder (56) to move the claw arrangement (34) and the release plate (46) respectively in opposite directions.

Description

DescriRtion 2335349 The invention relates to a collet for a cutting

machine.

Industrial cutting machines comprise a cutting disk rotating at a high rotational speed (1000 to more than 2000 revolutions per minute), towards which a product loaf (loaf of cheese, loaf of sausage, side of bacon etc. ) is to be advanced at a constant speed on a path extending downwards at an angle. In order to precisely control the velocity of the advanced product loaf which is to be cut, more particularly to be also able to rapidly return to zero for idling cuts, a collet cooperates with the rear loaf end, which is driven by a spindle drive. The collet has a claw arrangement, which in the operative position engages in the rear product end. Following cutting of the product loaf, the claw arrangement is withdrawn from the product loaf and in order to obtained a rapid and forced release from the collet of the loaf end which can no longer be cut on the cutting machine, a release device is provided, which is forcibly actuated.

In known collets of this type, two separate compressed air cylinders are provided, one of which actuates the claw arrangement, the other the loaf end release device. Each of these operating cylinders works via intermediate parts upon the load which is associated with said cylinder, so that the collet as a whole is mechanically complex and expensive and on the other hand also comprises a large number of parts, which is disadvantageous when cleaning the collet.

The present invention relates to development of a collet for a cutting machine with a frame, with a claw arrangement, which is supported by the frame and is displaceable between a retracted inoperative position and an extended operative position, with a release means, which is supported by the frame and is displaceable between a retracted inoperative position and an extended release 2 position, and with a drive device for moving the claw arrangement and the release means. The collet is developed in such a manner that it comprises a reduced number of parts, more particularly only one operating cylinder, but nevertheless allows for the desired movement of the claw arrangement and the release device in the same manner as the known collets.

This object is attained according to the invention by a collet for a cutting machine, with a frame, with a claw arrangement, which is supported by the frame and is displaceable between a retracted inoperative position and an extended operative position, with a release means, which is supported by the frame and is displaceable between a retracted inoperative position and an extended release position, and with a drive device for moving the claw arrangement and the release means, characterised in that the drive device comprises a single double-action linear motor, whose first end is coupled with the claw arrangement and whose other end is coupled with the release means and whose stroke is at least equal to the sum of the paths of the driven parts of the claw arrangement and release means, and the movement of the claw arrangement into the inoperative position is limited by a first abutment device and the movement of the release means into the inoperative position is limited by a second abutment device.

In a collet according to the invention, neither of the ends of the single linear motor which is used is directly supported against the frame. Rather, both ends of the linear motor are displaceably arranged, each of the ends being connected to one of the two associated loads which are to be moved (claw arrangement, release device). The setting of the end positions for the claw arrangement or the release device is effected by separate abutment devices, which cooperate either with the load or with the 3 linear motor or also cooperate with intermediate parts lying between the ends of the linear motor and the loads.

In this manner, the linear motor is not directly supported on the frame, but finds support on the frame in one direction of movement via the first abutment device and in the other direction of movement via the second abutment device once the corresponding load has been moved into the associated end position. In this manner, it is possible to use a first section of the overall stroke of the linear motor for moving the claw arrangement, a second section of the overall stroke of the linear motor for moving the release device.

Preferably, the linear motor is a double action operating cylinder which is preferably actuated by compressed air.

Preferably, the claw arrangement comprises: a claw shaft rotatably mounted on the frame, a plurality of claws arranged axially spaced apart and in alignment on the claw shaft and a claw drive lever supported by the claw shaft, and one end of the linear motor is articulatedly connected to the claw drive lever, whilst the other end of the linear motor is articulatedly connected to the release device. The individual claws of such claw arrangement work themselves into the rear loaf end over a substantially circular path. This is advantageous in view of a retention of the loaf end which is as secure as possible and therefore also allows for a rapid acceleration or deceleration of the product loaf during its advance towards the cutting disk of a cutting machine. In this respect, the force transmission between the linear motor and claw arrangement is simple and robust.

Preferably, the first abutment device comprises a claw abutment fixed to the frame, which cooperates with a part, e.g. the claw drive lever, nonrotatably mounted on the 4 claw shaft or cooperates with the linear motor. This ensures that on the one hand that the desired end abutment is obtained for the claw arrangement and on the other hand, however, that an unimpeded movement of the claw arrangement between its two end positions is obtained.

The release device can comprise release means rotatably or displaceably mounted on the frame and a drive rod, which is connected to said release means and is connected to the second end of the linear motor. Such a release device is characterised by mechanical simplicity and robustness.

Preferably, the drive rod is articulatedly connected at one end to an actuating element of the rotatably mounted release means and is articulately connected at its other end to a drive lever, which sits on a release shaft and is articulately connected to the second end of the linear motor. This is advantageous with a view towards a simple guidance of the release means which is also secured against contamination and a mechanically simple and robust drive thereof.

Preferably, the collet further comprises a transmitter element which is displaceable together with the release device and cooperates with a position sensor. With such a transmitter element it is possible with only low mechanical outlay to simultaneously use the release means to actuate a guide, which responds when the collet is driven towards the end of a new product loaf which is to be cut, with the claw arrangement retracted.

Preferably, the section of the frame on which the claw arrangement is mounted or the release device comprises product retaining means. This is advantageous in view of a reliable pressing of the claw arrangement into the rear end of a new product loaf.

The product retaining means can comprise a retaining blade parallel to the claw arrangement. This is advantageous in so far as the product support means can cooperate equally well with product loaves of different widths or different 5 diameters.

Preferably, the release means comprises a release plate and the retaining blade is constructed at the lower end of the release plate. This is advantageous with regard to a construction of the collet which is mechanically particularly simple, since the product support means is simply formed by a moulded-on section of a release plate.

The invention will be explained in further detail in the following with the aid of embodiments with reference to the drawings, in which:

Figure 1: is a view of a first collet; Figure 2: is a vertical longitudinal section through the collet according to Figure 1, the collet being shown at the start of an operating cycle; Figure 3: is a similar view to Figure 2, in which the collet is shown after the movement towards the end of a product loaf which is to be cut; Figure 4: is a similar view to Figure 3, the collet being shown following the introduction of the product loaf retaining claws into a product loaf end; Figure 5: is a similar view to Figure 4, although the collet is shown following the withdrawal of the product loaf retaining claws and [prior to] the extension of a product loaf release plate; 6 Figure 6: is a similar view to Figure 5, although the collet is shown following the extension of a product loaf release plate; Figure 7: is a similar illustration to Figure 1, although showing a narrower collet with drive device arranged offcentre; and Figure 8: is a vertical longitudinal section through the collet according to Figure 7.

In the sectional views illustrated in the drawings, the covered lines are also represented by continuous lines, i.e. the views correspond to illustrations as would be obtained if transparent material were used for the various collet components.

In the drawings, the reference 10 designates the entirety of the frame of a collet, as is used in cutting machines for the industrial cutting of loaves of cheese, loaves of sausage, sides of bacon, etc. The frame 10 comprises two frame plates 12, 14 extending in the longitudinal direction, which are held together by a front traverse 16 and a rear frame plate 18.

The lateral frame plates 12, 14 comprise receiving apertures 20, 22, in which support rails 24. 26 are accommodated, which form part of a feed carriage, not shown in the drawings, which is displaceable by means of a spindle drive, also not shown, in the direction perpendicular to the cutting plane of a cutting disk of a cutting machine (also not shown). Screws 28, which extend through tongues 30 of the frame plates 12, 14, are used for locking the frame 10 with the support rails 24, 26.

Mounted in the front lower end section of the frame plates 12, 14 is a claw shaft 32. This supports a plurality of 7 like claw elements 34, which are arranged behind one another in the axial direction and each comprise a radial securing section 36 in relation to the claw shaft 32 and a tapering claw section 38, which is supported by the securing section 36 and whose centre line has the form of a circular arc.

Mounted in a bearing eyelet 42 formed onto each front end of the frame plates 12, 14 are the ends of a tilting shaft 44, on which a release plate 46 sits. The release plate 46 comprises a plurality of successive recesses 48 in the longitudinal direction, through which the claw elements 34 can move in each case.

In order to drive the claw shaft 32, a drive lever 50 is provided, which is non-rotatably connected to the claw shaft 32 and is articulatedly connected at its free end via a hinge journal 51 to a drive head 52, which is in turn screwed onto the piston rod 54 of a double-action compressed air operating cylinder designated in its entirety by the reference 56. The housing of the operating cylinder 56 supports an extension 58 at its rear end, which extension is articulatedly connected via a hinge rod 60 to the drive lever 62, which is mounted on a shaft 64 which is mounted in the rear section of the frame plates 12, 14.

In order to move the release plate 46, a drive arm 66 is welded to said plate, the drive arm being articulatedly connected via a hinge journal 67 to the front end of a drive rod 68. The rear end of the drive rod 68 is connected via a hinge rod 70 to the free end of the drive lever 62.

The rear frame plate 18 supports two fittings 72, 74, to which an operating line, coming from a 4/4 control valve (not shown), can be connected in each case, and which are in turn connected to operating terminals 76, 78 of the 8 double-action operating cylinder 56. In this manner, the operating terminals 76, 78 can be selectively connected to a pressure line or a relief line or with one another (float position).

In addition, the rear frame plate 18 supports a contactfree position transmitter 80, which cooperates with the plate-shaped drive lever 62, which is non-rotatably connected to the shaft 64.

The collet described above operates in the following manner:

At the start of an operating cycle (following the release of the non-sliceable end section of a product loaf), the claw elements 34 and the release plate 46 adopt the position shown in Figure 2. The two operating chambers of the operating cylinder 56 are connected to one another (float position). If the collet is driven towards the end of a new product loaf 84, shown in broken lines in Figure 3, then the release plate 46 is moved backwards until it abuts against the front edges of the frame plates 12, 14. As a result of this retraction of the release plate, the drive lever 62 is pivoted via the drive rod 68 in an anticlockwise direction and triggers the position transmitter 80. During this movement, the operating cylinder 56 is shortened, whilst the claw elements 34 maintain their position, as shown in Figure 3.

As a result of the starting signal of the position transmitter 80, the control valve, which is connected to the operating lines leading to the fittings 72, 74, is adjusted in such a manner that the rear operating chamber of the operating cylinder 56 is acted upon by pressure, whilst the other operating cylinder is ventilated. In this manner the piston rod 54 is extended, since the rear end of the operating cylinder 56 is supported via the drive lever 9 62, the drive rod 68 and the release plate 46 against the frame 10 and cannot move further back. As a result of the extension of the piston rod 54, the claw elements 34 are then pivoted in an anti-clockwise direction and work their way into the material of the product loaf. In this respect, a retaining blade 86 acts as a reaction element. The retaining blade 86 is moulded onto the lower end section of the release plate 46 and extends over the entire length thereof. The position which is now reached is reproduced in Figure 4.

With the collet closed in this manner, the product loaf 84 is then advanced towards the rotating cutting disk of the cutting machine by a corresponding actuation of the spindle drive, not shown, which actuates the collet carriage. Shortly before the rear end of the product loaf reaches the cutting plane, the spindle drive is stopped in a controlled manner by a position transmitter cooperating with the spindle drive. Controlled by this position transmitter, the control valve connected to the operating lines is switched over, so that the front operating chamber of the operating cylinder 56 is now acted upon by pressure, whilst its rear operating chamber is ventilated. In this manner, the piston rod 54 is retracted and the claw elements 34 are withdrawn from the remaining section of the product loaf.

As a result of the circular movement of the connecting point between the drive lever 50 and the drive head 52, the entire operating cylinder 56 is pivoted in an anti- clockwise direction when the piston rod 54 is retracted, as can be clearly recognised from a comparison of Figures 4 and 5. This pivoting movement of the operating cylinder 56 is limited by the transverse 16, which simultaneously acts as a transverse abutment for the piston rod 54. In this manner, the position shown in Figure 5 is reached, which corresponds to that of Figure 3.

With the further pressure actuation of the front operating chamber of the operating cylinder 56, the cylinder of the operating cylinder 56 is then moved to the left in the drawing, so that the drive lever 62 is pivoted in an anticlockwise direction. The release plate 46 on the tilting shaft 44 is thus pivoted via the drive rod 68 in an anticlockwise direction, so that the remaining section of the product loaf is forcibly removed from the ends of the claw elements 34 and then falls under the force of gravity into a collecting receptacle for loaf residual sections positioned beneath the cutting machine.

The parts of the collet then adopt the position shown in Figure 6. It can be seen that this is the same position as already reproduced in Figure 2. At the end of an operating cycle, the collet is therefore immediately ready for the start of a new operating cycle, without the need for further adjustments.

It can be seen that the single operating cylinder 56 can generate both the movements of the claw elements 34 and the movements of the release plate 46, since its cylinder is not supported directly on the frame 10, but is coupled to the drive lever 52. The overall stroke of the operating cylinder 56 is used partially for the movement of the claw elements 34, partially for the movement of the release plate 46. Which part of the stroke is used for the movement of the claw elements 34 and which part of the stroke is used for the movement of the release plate 46 is determined by the position of the traverse 16 and the length of the drive rod 68 as well as the geometry of the drive lever 62 and the position of the hinge journals 60 and 70 provided thereon.

The collet therefore comprises a smaller number of components and only one operating cylinder, which allows for reduced manufacturing costs. However, the reduced number of components is also advantageous as regards the cleaning of the collet, since each additional component also means additional cleaning surfaces and edges and angles, which can only be kept perfectly and hygienically 5 clean with increased outlay.

In the second embodiment according to Figures 7 and 8, parts which correspond in function to the parts already described above are again provided with the same reference numerals. These parts do not need to be described again below.

The difference between the collet according to Figures 7 and 8 and the collet according to Figures 1 to 6 consists in that the collet according to Figures 7 and 8 has a reduced width, i.e. is designed for cutting narrower product loaves, and in that the operating cylinder 56 and the operating mechanism for the release plate 46 are accommodated in the upper half of the frame 10 in Figure 7, i.e. lie asymmetrically.

1 2

Claims

1. A collet for a cutting machine, with a frame (10), with a claw arrangement (32, 34), which is supported by the frame and is displaceable between a retracted inoperative position and an extended operative position, with a release means (46), which is supported by the frame (10) and is displaceable between a retracted inoperative position and an extended release position, and with a drive device for moving the claw arrangement (32, 34) and the release means (46), characterised in that the drive device comprises a single double-action linear motor (56), whose first end is coupled with the claw arrangement (32, 34) and whose other end is coupled with the release means (46) and whose stroke is at least equal to the sum of the paths of the driven parts (50, 66) of the claw arrangement (32, 34) and release means (46), and the movement of the claw arrangement (32, 34) into the inoperative position is limited by a first abutment device (16) and the movement of the release means (46) into the inoperative position is limited by a second abutment device (12, 14).

2. A collet according to claim 1, characterised in that the linear motor is a double-action operating cylinder (56), which is preferably actuated by compressed air.

3. A collet according to claim 1 or 2, characterised in that the claw arrangement comprises: a claw shaft (32) rotatably mounted on the frame (10), a plurality of claws (38) arranged axially spaced apart and in alignment on the claw shaft (32) and a claw drive lever (50) supported by the claw shaft (32), and one end of the linear motor (56) is articulatedly connected (66) to the claw drive lever (50), whilst the other end of the linear motor (56) is articulatedly connected (68) to the release device (46).

13

4. A collet according to claim 3, characterised in that the first abutment device comprises a claw abutment (16) fixed to the frame, which cooperates with a part, e.g. the claw drive lever (50), non-rotatably mounted on the claw 5 shaft (32) or cooperates with the linear motor (56).

5. A collet according to one of claims 1 to 4, characterised in that the release device comprises release means (46) rotatably or displaceably mounted on the frame (10) and a drive rod (68), which is connected to said release means (46) and is connected to the second end of the linear motor (56).

6. A collet according to claim 5, characterised in that the drive rod (68) is articulatedly connected at one end to an actuating element (66) of the rotatably mounted release means (46) and is articulately connected at its other end to a drive lever (52), which sits on a release shaft (64) and is articulately connected to the second end of the linear motor (56).

7. A collet according to one of claims 1 to 6, characterised by a transmitter element (62), which is displaceable together with the release device (46) and cooperates with a position sensor (80).

8. A collet according to one of claims 1 to 7, characterised in that the section of the frame (10) on which the claw arrangement (32, 34) is mounted or the release device (46) comprises product retaining means (86).

9. A collet according to claim 8, characterised in that the product retaining means comprises a retaining blade (86) parallel to the claw arrangement (32, 34).

10. A collet according to claim 9, characterised in that the release means comprises a release plate (46) and the 14 retaining blade (86) is constructed at the lower end of the release plate (46).

11. A collet as hereinbefore described.

12. A collet as hereinbefore described with reference to the drawings.