Patent GB-545002-A (GB)
Title: Improvements in wrapping machines
IPC: B65B57/04
Filed: 1941-01-24
Abstract: 545,002. Packing. FORGROVE MACHINERY CO., Ltd., and PARKER, M. Jan. 24, 1941, No. 978. [Class 94 (i) ] Relates to wrapping machines of the kind in which a procession of articles is fed by a conveyer to a machine and a number of wrappers are applied to each article while at spaced wrapping-stations, a number of articles at different wrapping stages being dealt with simultaneously. According to the invention, the devices for feeding the wrappers are so interlinked that each device can only operate if its predecessors operate successfully, and a detector is provided to render ineffective the first of the succession of feeding devices if an article should be missing from its place on the conveyer. Preferably the wrappers are fed by suction, and the suction is cut off from any of the feeding devices if either 'it or its predecessor fails to grip a wrapper. Fig. 1 shows diagrammatically the suction mechanism applied to the machine described in Specification 544,993 in which a main wrapper is applied around the body of a cylindrical article, the wrapper having serrated ends which project beyond the article. Inner cardboard and paper discs are then applied to opposite ends of the article, the serrations are closed over the inner disc, and an outer paper disc is applied over the serrations at the end occupied by the paper disc. The feeding of the wrapper and the discs is controlled by nine rotary suction valves I-IX and a series of trip valves A-J each of which. is associated with a rotary valve, and a main trip valve J which is operated by a mechanical feeler 69 that tests the procession of articles 32 along a conveyer 39. The valves are mounted in a common casing 45. Fig. 3, and the valves I-IX are geared to rotate together. At the proper times, the rotary valves admit suction from a central reservoir 78 to the associated wrapper-feeding members. Each valve consists of. a sleeve formed on its inner surface with grooves and provided with a rotary grooved plug, shown removed from its sleeve in Fig. 1. The rotary valves and the trip valves are so interlinked that in the event of any suction operation failing, due to the absence of a wrapper for example, all subsequent operations in respect of the affected article are stopped while the wrapping of the other articles that are in course of. being wrapped continues in the normal way. The feeler mechanism comprises a threearmed lever 49 which is oscillated by a cam 51. Pivoted to the lower arm of the lever is a tumbler 54 which is retained in either of two positions, "up" or "down," by a spring. The feeler 69 is carried by. a lever 66 which is rocked by the lever 49, on its downward stroke, against the action of a spring 68. On the upward stroke of the lever 49, the tumbler 54 strikes a stop 71 on the end of the lever 66. If an article 32 is in its correct place on the conveyer 39, the tumbler is moved to V retained in its " up " position, and on the next downward stroke of the lever 49 the tumbler moves an upper plunger 74 in the valve J. If an article should be absent from its place on the conveyer, the feeler 69 descends and the tumbler is moved to its "down" position, and on the next stroke of the lever 49 the tumbler moves a lower plunger 75 in the valve J. The valve J controls the communication of suction from the rotary valve VII to the valve I and permits or prevents the operation of a suction-operated peeler 81 of the kind described in Specification 492,787, [Group XVI] If an article is in its correct place on the conveyer, the peeler 81 removes a wrapper from the bottom of a stack 80 and conveys it to a suction pad 84, the application of suction to both of these members being timed by the valve I. If the peeler 81 fails to grip a wrapper correctly, air enters through the suction holes and causes the trip valve A to prevent the operation of the pad 84. If a wrapper. is correctly carried to the pad 84. the rotary valve II passes suction on to, and thus operates, the first, wrapper carrier 88. The other valves similarly operate to control the other, feeding devices, each trip valve being opened by its predecessor and serving to open its successor. All the feeding devices grips the wrappers by suction and are put out of operation if air enters the suction holes in the absence of a wrapper.