IMPROVED TOW BALER This invention relates to apparatus in a tow baler for transferring accumulated layers of tow, such as a tow of filamentary material for cigarette filter rods, from a tow bin or accumulating chamber to a baler chamber.

Reference is made to U.S. Patent Nos. 2,947,241; 2,947,242; and 3,351,992 for a description of a tow baler in which the present invention may be used. In the balers described in these patents, particularly U.S. Patent 3,351,992, there is an accumulating chamber or tow bin above a stripper bin, with a hold-up slide across the bottom opening of the tow. bin to form the bottom of the tow bin while a. previously completed bale of tow is being compressed, wrapped and removed from the baling press. Tow falls into the tow bin with the tow being guided by a tube so that the tow is deposited in parallel straight layers on the surface of a bed made of layers of tow. The tube may make a number of traverse cycles in one direction while simultaneously making a traverse cycle at right angles to the first direction. The tow bin is lowered gradually so that the upper level of the tow bed is kept at about a constant distance from the traversing tube. After the tow bale has been pressed out, a platen is moved up within the stripper bin below the tow bin to a position just below the hold-up slide, and then the hold-up slide is retracted by sliding it from the bottom of the tow bin to transfer the weight of accumulated tow to the platen. The ram that supports the platen then begins to lower the platen at gradual intervals to lower the column of tow within the stripper bin and to maintain a constant level of tow

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throughout the manufacture of the tow bale. When a bale cycle is completed, the tow bed has been completely lowered within the stripper bin, and then the hold-up slide is moved back into position to form the bottom of the tow bin so that a new cycle may be started.

When the hold-up slide is retracted from the bottom of the tow bin, it slides relative to the tow accumulated on its surface. This sliding action tends to move a portion of the tow out of position and to cause some undesirable entanglement of the tow. In order to eliminate the undesirable entanglement, the operators of the baler install a plastic sheet, such as a polyethylene sheet, over the hold-up slide and hold the sheet taut as it and the hold-up slide are moved into position beneath the bottom of the tow bin. The layers of tow are then deposited on top of the polyethylene sheet that covers the hold-up slide. When the hold-up slide is retracted, one operator holds the polyethylene sheet in place as another operator manually retracts the hold-up slide so that the hold-up slide moves relative to the polyethylene sheet and relative to the weight of the accumulated layers of tow supported on the sheet. The polyethylene sheet drops along with the accumulated layers of tow onto the platen where the sheet becomes part of the bale of tow. The costs for this plastic sheet and for the time required by the operators to install and to position this sheet become quite significant over a long period of operating time. Also, after the wrapping is removed from the bale of tow the bale tends to slide relative to the smooth plastic sheet and the bale may topple. The presence of the plastic sheet causes the unwrapped bale to be unstable.

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The problem of the prior art balers have been solved, in accordance with this invention, by having a sheet-like, flexible envelope, with the ends of the sheet being immobile, around the hold-up slide. The envelope forms a layer between the accumulated tow and the slide and the envelope is movable with the slide.

The tow baler has walls defining a chamber for receiving layers of tow for the formation of a tow bale of filamentary material; a platen movable in a vertical plane within the chamber for supporting the layers of tow as they are received; and a hold-up slide that is movable in a horizontal, plane to an operable position above the platen in the chamber, and being movable to an inoperable position outside the chamber; a second set of walls above the first-mentioned walls; the hold-up slide in the operable position forming with the second set of walls a tow accumulating chamber or tow bin for temporarily receiving, supporting and accumulating layers of filamentary tow upon the upper surface of the hold-up slide while a previously-formed bale is being removed from the tow baler below the hold-up slide cycle.. The improvement is an envelope around the hold-up slide, the envelope being movable to the operable or inoperable positions by the hold-up slide as the latter is moved to those positions. The upper surface of the envelope is an intervening layer between the upper surface of the hold-up slide and the accumulating layers when the envelope and the hold-up slide are in operable position. The envelope is slidable with respect to the hold-up slide as the latter is moved and is non-slidable with repect to

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the accumulating tow layers when it is moved from the operable position to the inoperable position.

The envelope is a length of sheet material looped around the hold-up slide and has its terminal ends secured outside the tow accumulating chamber or tow bin to one of the s-econd set of walls.

The envelope is in engagement with the leading and trailing edges of the hold-up slide and is slidable around both edges as the hold-up slide is moved to the operable and inoperable positions- More specifically, the envelope is in engagement with the leading and trailing edges of the hold-up slide, and the accumulating layers, when supported on the envelope drop from the leading edge onto the platen as the hold-up slide is moved toward the inoperable position. The envelope slides around the leading edge of the hold-up slide as ^' it is moved towar the inoperable position.

The details of the invention will be ^' described in connection with the accompanying drawings, in which

Fig. I is a diagrammatic elevational view of part of a tow baler illustrating the platen positioned beneath the hold-up slide and envelope which are across the bottom of the accumulating chamber or tow bin in the operable position with the accumulated layers of tow supported by the hold-up slide;

Fig. 2 is a similar view as that shown in Fig. 1 except that the hold-up slide and envelope are being moved toward the inoperable position and the accumulated tow layers are dropping onto the platen. Fig. 2A is an enlarged view of a portion of the one shown in Fig. 2, and illustrates the hold-up

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slide and the envelope with a portion of the envelope broken away; and

Fig. 3 is a view similar to that shown in Fig. 1 except that the hold-up slide and envelope have been completely moved to the inoperable position and the accumulated layers of tow have been completely transferred to the platen.

In reference to Figs. 1-3, the diagram- matically illustrated tow baler ___ has a chamber 12, as formed by walls 14_, for receiving layers of tow for the subsequent formation of a bale of tow of filamentary material, such as is used for cigarette filter rods. A hydraulically operated ram ___ supports a platen I for upward and downward vertical movement within the chamber 12.

A tow accumulating chamber or tow bin 2_0 is formed by a second set of walls 2__ _> which are positioned above the chamber 12 and its walls 14. The tow accumulating chamber serves to temporarily receive, support and accumulate layers of filamentary tow 2Λ when a hold-up slide S has been moved from the inoperable position outside the tow accumulating chamber 20 to the operable position across the bottom opening of the two accumulating chamber 20. The hold-up slide in the operable position is located above the platen 18 and the chamber 12.

The filamentary tow is deposited in parallel straight layers in the tow accumulating chamber 20 by the tube ^, which is caused by means not shown to traverse in two different directions.

The hold-up slide 26 is supported for sliding movement in the horizontal plane by the guide frame 30_ and guide rollers 3_2, and has an upper flat surface 34_, a leading edge 3_6 and a trailing edge 38 (Fig. 2A).

A sheet-like member 40 _^ , formed by a predetermined length of suitable material, such as biaxially oriented sheeting made from a polyester (polyethylene terephthalate) , which envelopes or loops around the upper and lower surfaces and the leading and trailing edges of the hold-up slide 26 and is secured by its terminal ends 42_ to the outside surface of one of the walls 22 of the accumulating chamber 20. This sheet-like envelope provides an intervening surface for the accumulating layers of tow between the upper flat surface 34 of the hold-up slide and the accumulated tow layers 24 within the tow accumulating chamber 20 when the sheet-like envelope and the hold-up slide are in the operable position. As the hold-up slide' is moved either to the operable or inoperable position, the movement of the hold-up slide causes the sheet-like envelope to be moved either to the operable or inoperable -position. As the sheet-like envelope is being moved, its intervening surface slides with respect to the hold-up slide but not with respect to the ^• accumulated tow layers.

The hold-up slide 26 moves within and relative to the sheet-like envelope-40, with the envelope being in engagement with the leading and trailing edges of the hold-up slide and being slidable around those edges as the hold-up slide is moved to operable and inoperable positions. Thus as the hold-up slide is moved toward either the operable or inoperable position, it causes movement of the sheet-like envelope to either the operable or inoperable position. The accumulated tow layers 24 resting on the surface of the envelope successively drop from the leading edge 36 of the hold-up slide to

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the platen 18 as the hold-up slide moves toward the inoperable position, as shown in Fig. 2 and Fig. ^" 2A. In this manner the surface of the envelope does not slide relative to the accumulated tow layers, but drops away from those layers as the hold-up slide retracts. Prior to the retraction of the hold-up slide, the platen 18 has been moved up to the hold-up slide after the tow bale, which the platen had previously supported, had been pressed out. The accumulated tow layers thus drop only a very short distance, e.g., about 2-3 cm., from the hold-up slide and the envelope to the platen.

It can now be readily appreciated that the accumulated tow layers in the tow accumulating chamber or tow bin 20 can be transferred to the platen in chamber 12 without undesirably becoming entangled.