FR2761921A3 - Cable store for building material cutting machine - Google Patents

Abstract

The cable store cuts by means of a closed piece of cable or wire. The cutting part can be moved by a drive disc and is kept taut by a feed device. The store (2) consists of a carrier mounting, to which two groups of pulleys (7,8) are fixed on two fixed axles (6,8).The free length of the cable or wire (3) can be adjusted, depending on the number of times it is wound round these groups of pulleys. The individual pulleys in each group may be fitted on the axles independently of each other and able to be rotated in opposite directions

Description

The invention relates to a cable storage device for a

  cutting machine for cutting building materials using a cable or wire, which forms a closed loop and has an abrasive action, the loop being caused to circulate by a drive pulley and being tensioned permanently using

an advance device.

  Such cutting machines, also referred to as cable saws, are used for

  cut large concrete blocks or also stones.

  The closed loop of the abrasive cable or wire is applied around the concrete block or stone and is tensioned using the feed device. The feed device generally acts on the drive pulley, which causes the abrasive action wire to move in a circulation movement. The two drive and feed (tension) functions can however also be assumed by different pulleys. During the cutting operation, the wire loop is kept permanently tensioned by the feed drive, and

  different feed rates can be set.

  Since the parts to be cut most of the time do not have very large dimensions, it would be irrational to size the chassis, with a value such that the loop of circulating wire can be driven, in a single stroke through the set of

  part to be treated. On the contrary it is usual to advance step by step

  step, in which case the circulating wire must be shortened, by the released length, after each return of the tension pulley, in the basic position. Since cutting off excess length has the most diverse disadvantages, we have not come to

  use cable storage devices.

  Such cable storage devices have been known for some time in different embodiments. In a variant according to WO 95/28263, a fixed lower roller support and a roller support that can be moved by means of a feed motor are arranged on a chassis. Both the two drive rollers and the two rollers of the cable storage device, which can cooperate with different rollers of the fixed roller support, are arranged on the mobile roller support. Since this cable storage device acts like a muffle, modified cable guidance between the cable storage rollers results in a different gear ratio. For a constant feed speed, the abrasive action wire is pulled through the material to be cut at a feed speed

  different depending on the number of windings.

  The problem of a different gear ratio from the winding of the cable released during sawing has

  was avoided in the case of construction according to EP 279305.

  This construction provides that not only the drive roller, but also the deflection roller provided for the accumulation is moved by the advance drive device. In this solution, a drawback stems from the fact that the chassis necessary as a guide system for the advance must be extended by the length of the winding between the

rollers.

  This is why the invention aims to create an accumulation device for cable, which is characterized by a compact and technically simple type of embodiment and with the help of which the drawbacks mentioned

  previously are effectively avoided.

  This problem is solved in accordance with the invention thanks to the fact that the cable storage device is constituted by a support frame, on which respectively a group of pulleys is arranged on two fixed axes during the operation of the cutting machine, the free length of the cable or wire can be modified by the number of windings around these

pulley groups.

  Thanks to the fixed mounting of the two groups of pulleys, which constitute the cable accumulator, during the cutting operation, on the one hand the reduction ratio is not influenced by the number of windings around these pulleys. On the other hand, due to the functional separation of the cable storage device from the advance device, the embodiment of the latter can be kept as compact as possible as is the device. cable storage. It is advantageous that the different pulleys of each group of pulleys can be mounted independently of each other on the axes and be rotated relative to each other. Thanks to the independent mounting of the different pulleys, the tensile load is distributed uniformly over the entire length of the coiled cable, which avoids the application of excessive stress to

individual zones.

  In addition it can be foreseen that the distance of the axes

  of the cable storage device can be changed.

  The cable storage device can therefore be adapted to different stroke lengths. The distance between the groups of pulleys of the cable storage device is adjusted so that a cable loop on the cable storage device precisely receives each length of cable, which is released when the device returns from the end point to the point

of departure.

  According to another characteristic of the invention, the shortening of the length of the cable or of the wire, which results from a winding around the groups of pulleys, is equal to the length of the cable of the wire, which is released when the device returns. in advance from the deployed position

  maximum, in the basic position.

  Other features and benefits of

  the invention will emerge from the description given below

  taken with reference to the accompanying drawings, in which: - Figure 1 shows the plan view of a cable storage device according to the invention; - Figure 2 shows the plan view of the associated device of the device of Figure 1; - Figures 3a to c illustrate an operation of

  this cable storage device.

  The arrangement of the cable storage device according to the invention is shown in Figures 1 and 2. The cutting machine 1 and the cable storage device 2 are arranged side by side, being however independent of the functional point of view. The wire or cable with abrasive action 3, which forms the closed loop, is driven according to a movement circulating by means of the drive pulley 4. On the other hand, on the support frame 4 is arranged a feed motor 13, by means of which the speed of advance of the saw wire 3 is determined by displacement of the drive pulley 4. The stroke of the drive pulley 4 is characterized by h. If we consider the shape of the saw wire 3, the latter runs on an input roller 11 to the drive pulley 4, from where it ends at the cable storage device 2, passing over the swiveling idler roller 10. Since the outgoing cable is accumulated, but not the cable in tension, the torque of the cable saw drive device can be transferred quickly without loss of sawing force to the material to be sawn ( concrete, masonry, stone and similar materials). The saw wire 3 is then guided through the output roller 12 to the workpiece, which must be cut. Likewise the input roller and the output roller 12 can be arranged so as to be able to pivot, to allow adaptation to

the respective cutting operation.

  The cable storage device 2 consists essentially of two groups of rollers 7 and 9, which are mounted so that they can rotate on two axes 6 and 8. The support or swiveling of the different pulleys 7a-e and 9a-e is independent so that the different pulleys can rotate with respect to each other to compensate for any slippage. During the operation of the cutting machine 1, the distance a between the two axes 6 and 8 of the cable storage device 2 is kept constant. However it is possible to adjust the distance d on the stroke h of the cutting machine 1 so that the return of the drive pulley 4 from the maximum deployment position to the basic position can be compensated by the winding of the wire 3 around the pulley groups 7 and 9. Referring to Figures 3a to c, we will explain the operation of the cable storage device according to the invention, with reference to another embodiment. This example differs from the previous ones in that the pulley groups of the cable storage device are arranged by being pivoted by 90 relative to the plane of the cable drive pulley. At the start of the cutting operation - as illustrated in Figure 3a - the saw wire 3 passes in front of the cable storage device, since no excessive length of wire has yet to be absorbed. However, each time the feed device returns from the maximum deployment position to the basic position, the necessary shortening of the saw wire 3 is obtained under the effect of the winding of a loop of the wire around two pulleys, located opposite, groups of pulleys 7 is 9. Consequently, the device

  cable accumulation is increasingly "filled" (Figure 3b) until finally the final state shown in Figure 3c is reached.

Claims (4)

  1. Cable storage device for a cutting machine for cutting building materials using a cable or wire, which forms a closed loop and has an abrasive action, the loop being brought to circulating by a drive pulley and being permanently tensioned using a feed device, characterized in that the cable storage device (2) consists of a support frame (5), on which respectively a group of pulleys (7, 9) is arranged on two axes (6, 8) fixed during the operation of the cutting machine (1), the free length of the cable or wire (3) being able to be modified by the number of wraps around these groups of pulleys (7, 9).   2. Cable storage device according to claim 1, characterized in that the different pulleys (7a-e; 9a-e) of each group of pulleys (7, 9) are mounted independently of each other on the axes (6, 8) and can rotate relative to each other to others.   3. Cable storage device according to claim 1 or 2, characterized in that the distance (d)   axes (6, 8) can be changed.   4. A cable storage device according to claim 3, characterized in that the shortening of the length of the cable or wire (3), which results from a winding around the groups of pulleys (7, 9), is equal to the length of the cable or wire, which is released when the advance device returns from the deployed position   maximum, in the basic position.