Positioning fixture to a rubber chain retreading press

Abstract

The formed fixture to a rubber chain retreading press includes a steel chassis (2) on which running ways (4) for moving a tensioning car (5) are mounted, wherein two gear racks (3), part of the drive of the tensioning car (5), are mounted on the steel chassis (2) parallel to the running ways (4). On the tensioning car (5) is mounted a tensioning drum (1) mounted on a shaft (24) bearing by bearing bodies on a stationary stand (7) and an hinged stand (9). The tensioning drum (1) is capable of being tilted by means of a hydraulic cylinder (22), and at each end of the tensioning drum (1) it is possible to mount movable separable stops (21 and 31), and in the middle of the tensioning drum (1) a power belt (27) is fixed, with towing ropes (28) attached and clamps (29) clamped thereto. On either side of the press body beams (14) are located to which lower fixed roller ways (10) and upper movable roller ways (6) are mounted by means of braces.

Description

[0001] Positioning fixture to a rubber chain retreading press

[0002] Technical field

[0003] This invention relates to a positioning fixture to a rubber chain retreading press, which will find application in the field of both transport engineering and agriculture in the regeneration of rubber chains.

[0004] Background

[0005] Rubber chains can be mounted on mini excavators and mini loaders, on tractors and harvesters as well as on heavy transport and construction machinery. The design and material of the rubber chains ensure longer service life, stability and operator comfort when operating the machine. The supplied rubber chains for construction and agricultural machinery are a combination of high wear resistance and minimal vibration.

[0006] Rubber chains for construction and agricultural machinery are made from a compound of natural and synthetic rubber, with anti-abrasive chemical agents added to reduce the percentage of wear caused by friction on abrasive or compact surfaces. Retreading is a process that extends the life of the rubber chain for several more lifetimes by rebuilding the worn tread and the worn guide or drive buffers, which has both economic and environmental advantages. The retreading process reuses the base of the chain, the so-called carcass, on which new tread and new leading or drive buffers are manufactured. In this way, the cost of the rubber chain is significantly reduced and the disposal of the already worn chain into the environment is prevented.

[0007] The retreading of rubber chains is carried out in specific sections limited by the length of the moulding die. This necessitates moving the rubber chains after each stage is completed. In practice, there is no known device by means of which the mounting, movement and dismounting of rubber chains is carried out.

[0008] Technical nature of the invention

[0009] It is an object of the invention to provide a positioning fixture for a rubber chain retreading press, which provides for the recovery of rubber chains at specific sections, depending on the length of the moulding die of the press, by securing accurate positioning of the rubber chains on the press, after completion of each stage.

[0010] The problem is solved by creating a positioning fixture on a rubber chain retreading press, which includes a steel chassis on which running ways are mounted for moving a tensioning car. On the steel chassis, parallel to the running ways, are mounted two gear racks forming part of the drive of the tensioning car, which drive is also accomplished by two hydraulic motors via gears. The movement of the tensioning car is carried out by means of running wheels attached thereto. A tensioning drum mounted on a shaft bearing by means of bearing bodies on a stationary stand and a hinged stand is mounted on the tensioning car. The tensioning drum is tiltable by means of a hydraulic cylinder, wherein the tensioning drum is driven by a hydraulic motor and a second gear meshed with another gear mounted on the tensioning drum. At each end of the tension drum, a possibility to mount movable separable stops is provided to limit lateral displacement of the rubber chains, and, in the middle of the tension drum, a power belt is secured by means of a plate, to which pulling ropes are attached and clamps clamped thereto. For the removal and subsequent movement of the rubber chain, two beams are established on either side of the press body, to which a right-hand plate and a left-hand plate are mounted, and a bottom plate is mounted on the underside of the press. The right, left and bottom plates are the base for mounting the lower fixed roller ways, and a short guide and a long guide are mounted on the right plate and left plate, guiding the movement of the upper movable roller ways, which are divided into segments moved in the vertical direction by other hydro-cylinders. The housing of the upper movable roller ways are made of a half-pipe with cut-outs for the passage of the other hydro-cylinders, to which half-pipe two sectors are welded, allowing the mounting of rollers.

[0011] In a preferred embodiment of the invention, a special slider is mounted between the lower die of the press and the rubber chain.

[0012] An advantage of the created positioning device is the provided possibility to accelerate the process of mounting, dismounting and moving the rubber chain on the press, as well as to reduce the labour intensity of the process. In addition, the fixture ensures accurate positioning of the rubber chain on the press, which increases the quality of the retread performed.

[0013] Description of the attached figures

[0014] This invention is illustrated in the appended figures, where:

[0015] Figure 1 is a front view of a positioning fixture attached to a rubber chain retreading press;

[0016] Figure 2 is a top view of the fixture of Figure 1;

[0017] Figure 3 is a side view of the fixture of Figure 1;

[0018] Figure 4 is a top and side view of a positioning fixture on a rubber chain retreading press up to 6 400 mm in length; and

[0019] Figure 5 is an axonometric view of a tension drum.

[0020] Examples of embodiments of the invention

[0021] The constructed positioning fixture to a rubber chain retreading press, shown in the appended figures, comprises a steel chassis 2 on which running ways 4 for moving a tensioning car 5 are mounted by bolted joints. On the steel chassis 2, parallel to the running ways 4, are mounted two gear racks 3 forming part of the drive of the tensioning car 5, the drive of which is also provided by two hydraulic motors 20 via gears 19. The movement of the tensioning car 5 is accomplished by means of running wheels 18 fixed thereto. On the tensioning car 5 is mounted a tensioning drum 1 mounted on a shaft 24, bearing by means of bearing bodies on a stationary stand 7 and a hinged stand 9. The tensioning drum 1 is, by means of a hydraulic cylinder 22, capable of being tilted to a certain angle, thus allowing the corresponding rubber chain to be mounted. The tensioning drum 1 is driven by a hydraulic motor 8 and a second gear 25 meshed with another gear 23 mounted on the tensioning drum 1 , whereby at both ends of the tensioning drum 1 the possibility is provided to mount movable separable stops 21 and 31 to limit the lateral displacement of the rubber chains. In the middle of the tensioning drum 1, a power belt 27 is fixed by means of a plate 26, to which are attached pulling ropes 28 and clamps 29 clamped thereto. For the removal and subsequent movement of the rubber chain, two beams 14 are provided on either side of the press body, to which are mounted a right-hand plate 16 and a left-hand plate 17, and on the underside of the press a bottom plate 15, the right-hand plate 16, the left-hand plate 17 and the bottom plate 15 being the bases for mounting the lower fixed roller tracks 10. A short guide 13.1 and a long guide 13.2 are mounted on the right plate 16 and the left plate 17, guiding the movement of the upper movable roller ways 6. The upper movable roller ways 6 are divided into segments moving in the vertical direction by means of other hydraulic cylinders 12, the housing of the upper movable roller ways 6 being made of a half-pipe with cut-outs for the passage of the other hydraulic cylinders 12, to which half-pipe two sectors are welded to allow the mounting of rollers 30. Between the lower die of the press and the rubber chain a special slide 11 is mounted, which is an aluminium board, which aluminium slide 11 prevents the formed cams of the rubber chain from falling back into the lower die and allows the chain to slip and move to the next vulcanization step.

[0022] The use of the created positioning fixture to a rubber chain retreading press is dependent on the length of the rubber chains being regenerated.

[0023] When the rubber chains are from 5944 to 6400 mm long, the rubber chain is clamped in the upper branch in a suitable manner at two places about 2200 mm apart and lifted and mounted on the press by means of a mounting crane with two hoists. After insertion by means of the upper roller ways 6, the chain is lifted and the material for the inner cams is inserted into the space created in the lower die. Strips of unvulcanised rubber are placed in the space between the cam material and the press, which after pressing will restore the scraped inner layer of the rubber chain carcass. The material for the restoration of the tread part, also in the form of strips of unvulcanised rubber, is placed on top of the chain as well as the material for the formation of the new chain grippers and the press is closed, the vulcanisation taking place at a certain temperature and pressure. After the first vulcanization cycle is completed, the rubber chain with the cams and grippers formed thereon is removed from the lower die by means of the two upper roller ways 6 moved in the vertical direction by the other hydraulic cylinders 12. Between the lower die and the newly formed cams the special slide 11 is mounted and the chain is lowered onto it, creating the conditions for its displacement and subsequent vulcanisation. By means of the power belt 27 clamped to the tensioning drum 1 and the pulling ropes 28 attached to the belt 27, and by means of the clamps 29 clamped to the chain, the drum 1 is rotated and the rubber chain is moved and set for the second vulcanisation cycle. By means of the other hydraulic cylinders 12 and by means of the upper roller ways 6, the chain is lifted and the special slide 11 is removed, and the material for the inner cams is placed in the space created in the lower die. Strips of unvulcanised rubber are placed between the cam material and the die and, after pressing, restore the inner layer of the rubber chain carcass. Strips of unvulcanised rubber are placed on top of the chain to restore the tread part of the chain as well as the material to form the new grippers and the press is closed. After the entire vulcanization process is completed, the rubber chain is released from the lower and upper dies and the upper roller ways 6 are lifted and the recovered chain is removed from the die. The chain is removed from the press after it has been clamped in two places by two hoists and a mounting crane standing at approximately 2200 mm.

[0024] Where the rubber chains are 6400 to 10060 mm long, the tensioning drum 1, mounted on the tensioning car 5, is used to provide the required tension to the rubber chain, which is driven by the hydraulic motors 20 and by the gears 19 meshed to the gear racks 3. The tensioning car 5, together with the tensioning drum 1, is moved to a position permitting the installation of a chain of an appropriate length. The divisible stop 21 is removed from the tension drum 1 to ensure unobstructed mounting of the rubber chain on the tension drum 1 , which is released from the stationary support 7 and raised by means of the hydraulic cylinder 22 to an angle of about 8°. The rubber chain is suitably clamped in two places about 2200 mm apart by two hoists and mounted simultaneously on the press and on the tension drum 1 by means of the mounting crane. When the rubber chain is mounted on the tensioning drum 1, it is inserted into the vacated space between the tensioning drum 1 and the tensioning car 5. The tensioning drum 1 is then lowered back onto the stationary support 7 by means of the hydraulic cylinder 22 and bolted to it. Next, the rubber chain is symmetrically positioned on the tension drum 1, the separable stops 21 and 31 being moved relative to the width of the regenerated belt so as to prevent the belt from shifting as the tension drum 1 rotates. After the rubber chain is mounted on the tension drum 1 , it is moved backwards by the movement of the tensioning car 5 until the necessary tensile force is achieved to prevent the rubber chain from slipping during its rotational movement. After the chain is inserted by means of the upper roller ways 6, it is lifted and the material for the inner cams is inserted into the space created in the lower die.

[0025] Strips of unvulcanised rubber are placed in the space between the cam material, which after pressing will restore the shredded inner layer of the rubber chain carcass. The material to restore the tread part in the form of strips of unvulcanised rubber and the material to form the new grippers of the rubber chain is placed on top of the chain and the press is closed. The vulcanisation process of the first step is carried out for a certain time at a certain pressure and temperature. After the first vulcanization cycle is completed, the rubber chain together with the cams added thereto is removed from the die by means of the two upper roller ways 6, which are moved in the vertical direction by means of the other hydraulic cylinders 12. Between the lower die and the newly formed cams the special slide (aluminium board) 11 is mounted and the chain is lowered onto it. This allows the rubber canvas to be moved for the next vulcanisation step. Due to the long length of the chain, if a sag occurs, it can be reduced by tensioning with the tension drum 1 within the permissible effort. By driving the tensioning drum 1 by the hydraulic motor 8 and the other gears 23 and 25, the rubber chain is moved to the required position for the next vulcanisation cycle. With the aid of the other hydraulic cylinders 12 and by means of the upper roller ways 6, the chain is lifted, the special slider 11 is removed, and the material for the new row of cams is added. In the space between the cam material, strips of unvulcanised rubber are inserted which, after pressing, will restore the scraped inner layer of the rubber chain carcass. The material for the restoration of the tread part in the form of strips of unvulcanised rubber and the material for forming the new grippers of the rubber chain is placed on top of the chain and the press is closed. These manipulations are repeated until the rubber chain is covered with the new elements (cams and tread) along its entire length. The next operation is to remove the rubber chain from the press. By means of the other hydraulic cylinders 12, the upper roller ways 6 are lifted and the recovered chain is removed from the die.

[0026] The tensioning car 5 together with the tensioning drum 1 are moved forward. The divisible stop 21 is removed and the tension drum 1 is released from the stationary stand 7 and, with the aid of the hydraulic cylinder 22, raised to the required angle of about 8°. The clearance created between the tensioning drum 1 and the tensioning car 5 is sufficient to pass the regenerated chain together with the newly formed cams, tread and grippers.

[0027] The chain is appropriately clamped in the upper branch at two locations spaced approximately 2200 mm apart by two hoists and is removed simultaneously from the press and the tension drum 1 by means of the mounting crane.

[0028] The positioning fixture created speeds up the process of mounting, dismounting and moving the rubber chain onto the press, which is a labour-intensive process. It ensures accurate positioning of the rubber chain on the press, which increases the quality of the retread.

Claims

CLAIMS1. A positioning fixture for a rubber chain retreading press, characterized in that it includes a steel chassis (2) on which running ways (4) are mounted for moving a tensioning car (5), wherein on the steel chassis (2), parallel to the running ways (4), are mounted two gear racks (3) forming part of the drive of the tensioning car (5), which drive is also provided by two hydraulic motors (20) via gears (19), and the movement of the tensioning car (5) is effected by means of running wheels (18) fixed thereto, whereby a tensioning drum (1) mounted on a shaft (24) is established on the tensioning car (5), bearing by means of bearing bodies on a stationary stand (7) and an hinged stand (9), which tension drum (1) is tiltable by means of a hydraulic cylinder (22), whereby the tension drum (1) is driven by a hydraulic motor (8) and a second gear (25), meshed with another gear (23) mounted on the tension drum (1), whereby at each end of the tension drum (1) the possibility is provided to mount movable separable stops (21 and 31 ) to limit the lateral displacement of the rubber chains, and in the middle of the tensioning drum (1) a power belt (27) is attached by means of a plate (26), to which pulling ropes (28) and clamps (29) are attached, whereby, for the removal and subsequent movement of the rubber chain, two beams (14) are established on either side of the press body, to which a right-hand plate (16) and a left-hand plate (17) are fitted, and on the underside of the press a lower plate (15) is mounted, the right (16), left (17) and lower (15) plates being the base for mounting lower fixed roller ways (10), and a short guide (13.1) and a long guide (13.2) being mounted on the right plate (16) and left plate (17), guiding the movement of upper movable roller ways (6), divided into segments moving in the vertical direction by another hydraulic cylinder (12), the housing of the upper movable roller ways (6) being made of a half-pipe with cut-outs for the passage of the other hydraulic cylinders (12), to which half-pipe two sectors are welded to allow the mounting of rollers (30).

2. A positioning fixture for a rubber chain retreading press, according to claim 1, characterized in that a special slide (11) is mounted between the lower die of the press and the rubber chain.

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