Patent GB-818645-A (GB)
Title: Improvements in or relating to an apparatus for producing a knot in flexible material
IPC: B65B51/08
Filed: 1957-02-26
Abstract: 818,645. Knot-tying devices. SACHSENROEDER, G. Feb. 26, 1957 [March 20, 1956], No. 6378/57. Class 112 [Also in Group XVII] In a binding and knot-forming apparatus comprising a passage through which string or the like is adapted to be conveyed by a gaseous medium, and devices for measuring, tightening and cutting the string, the knot-forming passage is provided in a casing which is formed with an aperture to receive the article being bound, and is sub-divided along the passage into a plurality of parts adapted to be moved apart to allow the string to pass between said parts and to tighten on to the article being bound. Tlhe casing, which is cylindrical in form and contains an axial aperture 13 for the article 6 being bound, also contains two transverse joints 14 and an axial diametrical joint 15 which divide the casing into three half-discs 7, 8, 9 and three complementary half-discs 10, 11, 12. The inner half-discs 8, 11 are formed with radial inlet and outlet passages 18 and 19 respectively. The inner faces of the outer halfdiscs 7, 10 and 9, 12 are formed with grooves which co-operate with the contiguous faces of the inner half-discs 8, 11 to provide loops 1 and 2. The latter are interconnected by an axial passage 4 formed in the half discs 8, 11 and intersected by the joint 15. The outer end of loop 2 is connected to the inlet 18, and the outer end of loop 1 is connected by an axial passage 5, formed in the central half-discs 8, 11 and intersected by the joint 15, to a vertical passage 3, formed by a groove in the half-disc 12, and connected in turn to the outlet passage 19. Bolts 16 which pass axially through the half-discs are secured to the inner discs 8, 11, and compression springs 17 mounted on said bolts press the outer half-discs against the inner half-discs. The inner half-discs are carried at the ends of arms 22 of a cross-jointed structure pivoted together by a pin 41 and provided with arms 23 in the form of handles. A spring 33, interposed between the arms 22, biases the latter apart to separate the half-disc groups 7, 8, 9 and 10, 11, 12 about the joint 15. The groups may be brought together by pressure exerted on the handles 23. Inlet 18 is connected by a pipe 24 to a container 25 housing a spool of string 21, and the container 25 is connected by a pipe 26 to a compressed air container 27 charged by an air compressor 28. A spring-closed stop valve 29 mounted at the inlet 18 is connected by a cable 31 to a lever 30 pivoted on one of the handles 23. A spring 32 is interposed between lever 30 and said handle, and is stronger than spring 33. The piston rods of air cylinder 37 are in the form of pins 39 adapted to enter the passages 18 and 19. The piston rod of an air cylinder 45 is in the form of a knife 46 adapted to enter the inlet passage 18 between valve 29 and the pin 39. Cylinders 37 are interconnected by a pipe 40 and one cylinder 37 is connected by a passage 42 in one arm 22 with the pivot pin 41. Another passage 44 in said arm connects the pivot pin with cylinder 45. The pivot pin is formed with a transverse bore 43 and is also connected by a passage and pipe to the air container 27. The arrangement is such that when pressure is applied to the handles 23 and lever 30, the latter remains unoperated until the half-disc groups abut about the joint 15, when further pressure operates lever 30 for opening valve 29. Bore 43 is now out of alignment with passages 42 and 44, so that pins 39 and knife 46 are in the retracted position. Air pressure then carries the string 21 through the knot-shaped passage, and the string on emerging from outlet 19 is stopped by the constricted end 35 of an extension 34 to the outlet. Extensions 34 of various length may be fitted. On releasing the handles, spring 33 moves arm 22 apart, when bore 43 first becomes aligned with passage 42 to charge cylinders 37 is connected by a passage 42 in one arm 18 and 19 to clamp the string therein. Continuing opening movement of arms 22 serves to draw the string through the joints 14 and the open joint 15, and to tighten the knot on the article 6. Near the end of the opening movement bore 43 becomes aligned with channel 44, whereby knife 46 is operated to sever the string in the inlet passage 18. It is stated that the handles 23 may be so arranged that pressure thereupon results in opening the arms 22, a spring or an air cylinder being interposed between the latter for closing the same. It is also stated that the string may be measured by means of a pair of rollers or by measuring the quantity of air required to convey a desired length of string. The opposed groups of half-discs may be provided with suitable jaws adapted to compress the article 6.