IL45841A - Cotton tamping device - Google Patents

Description

A COTTON TAMPING DEVICE The invention relates to an improved mechanism for tamping and compacting freshly harvested cotton on pallets into so-called "modules", in which form they can be readily transported and stored.

Such modules are compacted into blocks in module builders as known to the art which consist mainly of a box-shaped structure aligned over a pallet, and a tamping mechanism made to travel along the open top along the entire length of the structure. The tamping device is mounted on a bridge which spans the box-shaped structure and can be moved over its entire length in both directions; it consists mainly of a tamping board - of a length corresponding to the width of the module to be formed -which is attached to the lower end of a piston rod projecting out of a vertical hydraulic actuator, serving to operate it in reciprocating vertical motion. After the compacting operation the rear wall of the box is opened, the module builder is slightly raised and drawn away by a tractor, whereafter the module may be covered by a tarpaulin, tied to the pallet and carried off to a gin mill or into stores. The module builder is then placed on top of another pallet and the operation repeated.

These existing module builders equipped with vertical actuators are necessarily provided with means for detaching or folding the latter, as it normally rises to a height making travel along public roads impossible.

This height is necessary, as the tamping board, at the beginning of the compacting operation reaches down to about 3 feet above the pallet, while at the end of the operation it compacts the cotton near the upper edge of the module builder, requiring a piston rod of a length equal to the height of the module builder and, accordingly, a cylinder projecting above the upper rim of the box by at least 2.5 met* Another drawback of the existing tamping devices is the relatively great piston velocity which leads to rapid wear and tear of the actuators.

Still another drawback is that the piston rod projects vertically out of the cylinder without any side supports} for this reason any uneven distribution of cotton will result in an off-centre load on the tamping board and in eccentric contact between piston and cylinder, leading to premature damage to the walls.

In view of these drawbacks it is the object of the present invention to provide a tamping mechanism of low height, permitting unobstructed movement of the module along public roads.

Another object is to provide the tamping mechanism with a hydraulic actuator having a relatively low piston velocity. Still another object is to design the mechanism in such a manner that off-centre forces acting on the tamping board are not transmitted as eccentric forces to the hydraulic actuator.

The invention consists of a rectangular box-shaped cotton module builder and a bridge adapted to travel along its open top, the bridge being provided with a cotton tamping device which comprises a horizontal tamping board attached to a vertical beam slidingly guided in the centre of the bridge and adapted to be operated in reciprocating vertical direction by a hydraulic actuator of the cylinder-piston type, the tamping device being characterised by that 1) the actuator cylinder is placed in substantially horizontal position between the girders of the bridge, 2) a piston rod connected to the actuator piston is provided with at least two parallel drive wheels in the shape of sprocket wheels or pulleys rotatably mounted on an axle fastened to the end of the said piston rod at a right angle thereto, 3) the motion of the piston rod is transmitted to the tamping board by means of at least two chains or cables, one for downward and one for upward motion, whereof the chain for downward, tamping motion is fastened at its one end to the top portion of the vertical beam and at its other end to a fixed point on the bridge, and whereof the chain for upward motion is fastened at its one end to the bottom portion of the beam and at its other end to a second fixed point on the bridge, 4) at least three axles are rigidly fastened to the bridge with -heir axes at right angles to the direction of the beam, having guide wheels rota tably mounted thereon in such a manner as to guide one chain I around substantially half the circumference of one of the drive wheels remote from the actuator and the second chain around half the circumference of the remaining drive wheel facing the actuator.

Movement of the piston iu horizontal direction for a certain distance results in shortening the vertical portion of one chain by a length twice the distance travelled by the piston and in lengthening the vertical portion of the second chain by the same length, raising or lowering the beam and tamping board respectively.

In a preferred embodiment of the invention three independent parallel drive wheels are mounted on the axle fixed to the piston rod, whereof the centre wheel serves to raise the beam by means of the chain or cable attached to the bottom part of the beam, while the two external wheels serve to lower the beam by means of two parallelly guided chains or cables attached to the top portion.

In another embodiment the actuator cylinder is pivotally attached to the bridge at the end removed from the piston rod, so as to prevent eccentric forces from acting between piston and cylinder.

In the accompanying drawing which shows, diagrammatically, one embodiment of the invention^ ' Figure 1 is a section through a travelling bridge containing a hydraulically operated tamping mechanism, Figure 2 is a secsftion along A-A of Figure 1.

With reference to Figures 1 and 2 of the drawing a horizontal travelling bridge II is supported on two horizontal parallel rails 11 forming the upper edge of a module builder^ I, with its side walls 12 slightly . diverging in downward direction. The bridge comprises two longitudinal parallel girders 20 connected at their ends by two cross members 21 and 21'* The latter extend downwards beyond the lower edges of the girders 20 and contain four horizontal axles 23 which are, at their inne ends, held in supports 24 integral with and parallel to the cross members, with one rimmed wheel 22 each rotatably arranged on these axles. The wheels carry the bridge on the rails 11, enabling it to travel over the entire length of the module builder while being operated manually, or by mechanical or hydraulic means.

In the centre of the bridge a vertical tamper beam III is placed and guided by upper and lower rollers 30 and 30' arranged in parallel and at right angles to the girders 20. This tamper beam consists of two vertical plates or girders 31 , placed at a distance from each other close to the bridge girders and connected at their top by a top plate 32 and at their bottom by a horizontal tamping board 33 of a length commensurate with the space between the longitudinal side walls of the module builder.

A hydraulic actuator IV is horizontally placed between the bridge girders and comprises a cylinder 40, a piston 41 movable therein and a piston rod 42 attached to the piston and projecting out of the cylinder cover in the direction of the tamper beam III. The cylinder 40 is at its outer end pivotally connected to the bridge cross member 21 * allowing small angular movements of the actuator and thereby preventing eccentric forces from building up between piston and cylinder.

Three sprocket wheels or pulleys 43 which will be called the "drive wheels" are lined up on a common axle 44 held in an axle box 45 which latter is attached to the extreme end of the piston rod. Three sets of guide wheels 46, 47 and 48 are rotatably mounted on axle pins 49, 50 and 51 respectively which are firmly attached to the bridge and its girders. Two such sets (46, 47) project into the hollow space between the vertical girders 31 and are rigidly attached to the bridge girders by cross supports 52 and 54. The third set (48) is fastened to the bridge cross member 21. Two sets of chains or steel cables connect the wheels on the piston rod with the tamper beam III, one of the sets being connected to the top plate and one to the tamping board. Of these, two parallel chains or cables 53, shown in dashed-dotted lines, are symmetrically attached to the topplate and serve to lower the beam for the purpose of compacting the cotton by means of the tamping board 33j they run from the top plate < over the wheel set 46 - which comprises two parallel wheels -around half the front circumference of the drive wheels, with their other ends fastened to a strong cross beam 57, connecting the bridge girders. Means are provided at the ends of the chains or cables for tensioning them.

The second chain or cable 55, shown in broken lines, is attached to the tamper plate and serves to raise it together with the tamping board. It is arranged between the two chains or cables 53 and runs at first vertically from the tamping board to the pulley 47 which guides it in horizontal direction to the pulley 48 j this pulley turns it back to the drive pulley which it encircles around half of its rear circumference to an adjustable fixation point 56 on the bridge cross member 21. A helical tension spring 58 is interposed between the tamping board and the chain to keep the latter permanently tensioned.

The mechanism works as follows:- while the piston and piston rod moves forward, i.e. to the left of the drawing, due to liquid entering the rear end of the cylinder, the chains 53 are tensioned by the drive wheels and pull the tamper beam and tam ing board down-wards against the cotton in the module builder, while the second chain 55 slackens and gives way.

On the return stroke the chain 55 is similarly tensioned and the tamping board is pulled up to its uppermost position, whilst the chain 53 slackens.

The tamping and compacting of the cotton is interrupted whenever a nev load is dumped into the module builderj the tamping board is then used, as known to the ert, for smoothing the upper surface by moving it, along with the bridge, over the newly dumped cotton. It is obvious that the stroke of the beam and board becomes shorter with increasing height of the module, and in order to prevent excessive pressure, overflow valves or pressure relief valves are provided in the hydraulic control device.

The great advan age of the present mechanism, compared with the existing tamping mechanisms, is its low height, permitting the transport of the module builder along public roads without need to remove the cylinder.

' A second advantage is the lower piston velocity which is exactly half the tamping board velocity, resulting in less wear of the sliding surfaces of the actuator.

Finally no lateral forces act between the piston and the cylinder, owing to the pivoted attachment of the latter and to the fact that the chains or cables exert only axial forces on the piston rod.

The mechanism may undergo various alterations and modifications to be carried out by a person skilled in the art, without however deviating from the spirit of the invention and the scope of the following Claims.

Claims (1)

C L A I M S ;-

1. A rectangular box-shaped cotton module builder and a bridge adapted to travel along its open top, the bridge being provided with a cotton tamping device which comprises a horizontal tamping board attached to a vertical beam slidingly guided in the centre of the bridge and adapted to be operated in reciprocating vertical direction by a hydraulic actuator of the cylinder-piston type, the tamping device being characterised by that 1) the actuator cylinder is placed in substantially horizontal position between the girders of the bridge, 2) a piston rod connected to the actuator piston is provided with at least two parallel drive wheels in the shape of sprocket wheels or pulleys rotatably mounted on an axle fastened to the end of the said piston rod at a right angle thereto, 3) the motion of the piston rod is transmitted to the tamping board by means of at least two chains or cables, one for downward and one for upward motion) whereof the chain for downward, tamping motion is fastened at its one end to the top portion of the vertical beam and at its other end to a fixed point on the bridge, and whereof the chain for upward motion is fastened at its one end to the bottom portion of the beam and at its other end to a second fixed point on the bridge, 4) at least three axles are rigidly fastened to the bridge vith their axes at right angles to the direction of the beam, having guide wheels rotably mounted thereon in such a manner as to guide one chain around substantially half the circumference of the remaining drive wheel facing the actuator, the guide wheels being further-more disposed in a manner that movement of the piston in horizontal direction for a certain distance results in shortening the vertical portion of one chain by a length twice the distance travelled by the piston and in lengthening the vertical portion of the second chain by the same length, raising or lowering the beam and tamping board respectively. In a cotton module builder a tamping device as claimed in Claim 1 wherein three independent parallel drive wheels are mounted on the axle fixed to the piston rod, whereof the centre wheel serves to raise the beam by means of the chain or cable attached to the bottom part of the beam, while the two external wheels serve to lower the beam by means of two parallel chains or cables attached to the top portion. In a cotton module builder a tamping device as claimed in Claim 1 wherein the actuator cylinder is pivotally attached to the bridge at the end removed from the piston rod. A cotton module builder and a damping device mounted thereon substantially as hereinbefore described and illustrated in the accompanying drawing. Ε.ΑΛ Glucksman For the Applicants