Device for inserting and removing work stations circulating on chain

A device for carrying out a sequence of working steps on travelling work station wagons comprising an oval track wherein said work station wagons are circulating, wherein said wagons comprise at least one detachable connection element connected to a circulating chain which moves said wagons; at least one insertion and at least one removal guide track is provided on the outside of said oval track, wherein said at least one insertion and at least one removal guide track comprises a transfer point to which the chain is allocated; at least one coupling element is further provided at each transfer point via which the wagons may be coupled into the guide tracks on the side opposite of the side of said wagons comprising at least one detachable element, with at least one switchable points element located on said guide track, which during the insertion position, release said at least one coupling element and bring about the engagement of said detachable connection element to said chain or during the removal position, couple the coupling elements and removably detach said at least one detachable connection from said chain.

BACKGROUND OF THE INVENTION

To carry out a uniform sequence of working steps at a plurality of work stations, frequently, each individual working step is repeated at a stationary position, wherein a plurality of work stations, driven on a belt or a chain, passes by the location in which each particular working step is carried out.

A uniform sequence of working steps may, for example, be the assembly of a device, wherein the various assembly steps are carried out at different locations and the part to be assembled is moved on a work station from location to location for the various assembly steps to be carried out. A similar arrangement may be used in the production of molded parts, in which the working steps comprise cleaning the mold, providing the mold with a release agent, inserting a displacement body, filling the mold for the first time, curing the first molded part, removing the displacement body, filling the mold for the second time, curing the second mold contents, opening the mold and removing the molded part. Such working steps are carried out at different locations, wherein the mold is conveyed on a work station from one location to the other.

The work stations may take the form of work station wagons, wherein the work station wagons are moved by means of connection elements to the circulating chain drive which are provided and/or engaged on the wagons on one side.

The design of work stations in the form of independent work station wagons is particularly applicable when the initial and/or subsequent fitting out of the work station, or intermediate working steps which cannot be carried out on the chain, are carried out away from the conveyor system in terms of location. In this case, it may be necessary to remove individual work station wagons from the chain cycle and/or insert them into it.

SUMMARY OF THE INVENTION

The present invention relates to a device for carrying out a sequence of working steps on travelling work station wagons comprising

a) an oval track wherein said work station wagons are circulating, wherein said wagons comprise at least one detachable connection element connected to a circulating chain which moves said wagons;

b) at least one insertion and at least one removal guide track is provided on the outside of said oval track, wherein said at least one insertion and at least one removal guide track comprises a transfer point to which the chain is allocated;

c) at least one coupling element is further provided at each transfer point via which the wagons may be coupled into the guide tracks on the side opposite of the side of said wagons comprising at least one detachable element, with at least one switchable points element located on said guide track, which during the insertion position, release said at least one coupling element and bring about the engagement of said detachable connection element to said chain or during the removal position, couple the coupling elements and removably detach said at least one detachable connection from said chain.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a device for carrying out a uniform sequence of working steps on travelling work station wagons circulating on an oval track, wherein the wagons are moved by means of detachable connection elements to a circulating chain drive. The detachable connection elements are provided and/or engaged on one side of the wagon. The device of the present invention also composes at least one insertion and at least one removal guide track, to each of which a transfer point to the chain is allocated and is provided on the outside of this oval conveyor system. Coupling elements are further provided via which the wagons may be coupled into the guide tracks. On the other side of the wagon, switchable points elements are provided, in which insertion/removal positions release the connection elements and couple the coupling elements for removal purposes and/or uncouple the coupling elements and bring about the engagement of the connection elements for insertion purposes, which are provided at each transfer point.

An embodiment of the present invention comprises the chain circulating in an oval, for example, and the chain running in a guide channel. The wagons have guide rollers running on vertically projecting mountings in the guide channel and the wagons also comprise at least one carrier pin, wherein carrier cages located on the chain removably engage the carrier pin on the wagon. On the chain side, the transfer point may be designed in such a way that the outer boundary of the guide channel is interrupted so that the guide rollers may emerge laterally out of the guide channel and the carrier pin laterally out of the carrier cage which is open towards the outside.

In an embodiment of the present invention, the insertion and removal tracks may take the form of guide channels which are arranged parallel to the chain drive and at a distance from its guide channel, wherein the distance between the chain and the guide channel of the insertion/removal track approximately corresponds to the width of the work station wagon. On the outside of the wagon, guide rollers are then also provided, which run in the guide channel of the removal guide track after transfer from the chain to the removal guide track. At the transfer point, the guide channel of the removal guide track has interruptions, which are closed by means of points tongues if no transfer is to take place. If the wagon, which passed by the transfer point is to be removed, the points tongues are switched in such a way that they guide the guide rollers of the wagon into the guide channel of the removal track.

The insertion point is correspondingly designed. When inserting a wagon, care should be taken to ensure that the work station wagon is inserted in an accurately positioned manner with respect to the connection element to the chain, and with respect to the embodiment of the present invention, that the carrier pin of the wagon is introduced into the carrier cage of the chain.

Therefore, the present invention preferably provides that each work station wagon has a spacer with respect to the next wagon, wherein the spacing of the connection element parts on the chain (i.e., the carrier cages) have a spacing which corresponds to the length of the wagon and spacer combined. In this way, the wagon to be inserted is inserted at the free place on the chain, wherein the following wagon with its spacer pushes the wagon to be inserted precisely into the position in which the connection to the chain takes place.

Preferably, the insertion guide track has a load-dependent drive in which the maximum speed is higher than the chain speed. Preferably, the insertion guide track has a friction drive, which engages on the outer side (relative to the oval) of the wagon. This ensures that prior to transfer, the wagon to be inserted has a higher speed than the following wagon on the chain, so that during the transfer, the wagon to be inserted is pushed into the transfer position by the spacer of the following wagon.

The invention will be explained in greater detail with the aid of the drawings which follow:

FIG. 1shows a carousel10, with the chain1, circulating in an oval, on which the work station wagons denoted by Roman numerals circulate. A removal guide track20and an insertion guide track30are also shown in diagrammatic form. The transfer points are denoted by the broken-lined circles21and31.

The enlarged view ofFIG. 2shows that the circulating chain drive1comprising a guide channel2, which is formed by the two guide strips5and6, wherein the drive chain3runs inside the guide channel2. The chain has carrier cages4a,4b, functioning as a connection element part on the chain side to receiving such connection element from the wagon. The carrier cages4a,4bare arranged at a regular spacing. Guide rollers7a,7b, which run in the channel2as long as the wagon is guided on the chain are provided laterally on the work station wagons denoted by Roman numerals and are removably fastened to carrier cages4aand4b, respectively.

The removal guide track20also consists of a channel22, which is formed by guide strips25and26. On the side facing away from the chain drive the work station wagons have guide rollers8aand8bwhich in the event of transfer are engaged by switchable points tongues27aand27band are guided into the guide channel22of the removal guide track20; see wagon II. On the side opposite the points27aand27b, the guide strip5comprises a break or interruption so that the guide rollers7aand7bbelonging to the wagon to be removed, are moved out of the guide channel2and out of the carrier cage4aand4b, respectively.

FIG. 3shows an enlarged view of the points tongues, wherein the numerals denote elements identical with FIG.2. The top view shows the points tongues in the “transit” position, the bottom view shows the points tongues in the “transfer” position.

FIG. 4shows the insertion of wagon X, still in the waiting position inFIG. 2, at the position in which wagon II is removed in FIG.2. The end phase of the insertion, which explains the correct position for connection to the chain3, is shown. In the region of the deflection40of the chain, the work station wagons are considerably wider apart. In this region, wagon X is initially pushed in front of wagon I. At the time of transfer, i.e., when the guide rollers8aand8bof wagon X reach the points tongues37aand37b, wagon X to be inserted, is accurately positioned between wagons I and III via the spacer9so that the guide rollers7aand7bare accurately positioned in the carrier cages4aand4bof the chain3.

It will be readily apparent to the person skilled in the art that the connection elements between circulating chain and work station wagons, and the coupling elements to the insertion and removal guide tracks, may be designed differently from the views shown by way of example. For example, they may take the form of switchable electromagnets or rocker heels. It is essential to the invention that the guiding of the work station wagons for the purposes of this invention, insertion takes place on the one side and removal takes place on the other side, so that complicated points, in which that wagons must pass over structures, are avoided on the circulating chain drive. Both the circulating chain drive and the insertion and removal guide tracks may be arranged above the shopfloor without forming obstacles to the work station wagons travelling on their own wheels.