Patent GB-793882-A (GB)
Title: Improvements in or relating to apparatus for producing a knot in flexible material
IPC: B65B51/08
Filed: 1955-12-12
Abstract: 793,882. Sausages, necking and tying. SACHSENROEDER, G. Dec. 12, 1955 [Dec. 13, 1954; March 25, 1955], No. 35553/55. Class 28 (2). [Also in Groups VII and XVII] In a device for tying sausage skins (see Group VII), string 12, Fig. 7, is sucked by a vacuum pump 3 through a tube 9 which is looped into knot form, the skin 1 is positioned within the loop, and a pull is exerted upon the opposite ends of the string, whereby the latter leaves the tube through a slit provided in the longitudinal periphery of the latter and tightens upon the skin. To prepare the end of the skin 1, Figs. 15, 16, preparatory to tying a knot thereon, the flattened end of the skin is folded upon itself and is advanced into the vicinity of the tube 9. The folded-over end is then folded into concertina-like vertical pleats by means of blades which comprise an upper row 58 and a lower row 59 both pivoted at their rearward ends on a horizontal spindle 61, the blades being spaced apart horizontally at a distance sufficient to accommodate the vertical pleats. Spindle 61 is carried by a yoke 68 movable towards and away from tube 9, the blades passing between a pair of fixed parallel rods 62 on which are mounted a series of vertical plates 65. The rows of blades are biased apart by spring means, and each blade has a cam 63 formed on its outer edge, the cam on the central blade in each row being positioned nearest the pivot 61, and the cams on each side receding successively from the central cam. The arrangement is such that when yoke 68 is moved forwards, so that the open rows of blades pass through tube 9 and embrace the end of skin 1, and then is moved rearwardly, the cams 63 react in succession with the rods 62 and cause the blades to pivot towards each other from the centre outwards, whereby the end of skin 1 is drawn through tube 9 and is simultaneously folded from the centre outwards, the folded end being correctly positioned within tube 9 by the plates 65. The folds are gathered together by a pair of fingers 66 mounted one on each side of the blades on fixed pivots 67 and connected by rods 69 to yoke 68, whereby the fingers move inwardly against the bias of springs 70 when yoke 68 is moved away from tube 9. As shown, the blades are all the same depth, whereby the folded and compressed end is of rectangular form. Alternatively, the blades may decrease in depth from the centre outwards, whereby the folds also decrease in depth and the compressed end assumes a circular form in cross-section. It is stated that the end need not, in this case, be first folded upon itself. In a modification, Fig. 18, adapted to tie a skin, fed unidirectionally, at spaced intervals, the blades 58, 59 are slidably mounted in guides 73, and the cams 63 are mounted on separate rotary shafts 74 so as to act on the outer edges of the blades to move the latter inwardly against spring bias.- In this case two tubes 9 are provided, the tubes being positioned close to one another and connected in parallel to the vacuum pump, whereby a pair of knots is tied simultaneously, the skin then being severed, if desired, between said knots.