GB331527A - Improvements in and relating to wrapping machines and the like - Google Patents

Abstract

331,527. Baker Perkins, Ltd., and Booth, J. H. March 2, 1929. Packeting by wrapping-up.-Wrapping-machines, which may be of the type described in Specifications 215,902 or 326,831, are arranged so that, the presence of a wrapper in the wrapping position prevents the actuation of an electrical or pneumatic relay device adapted to cut out the machine drive. In the form shown in Figs. 1 and 5, a detector comprising a spring wire 7 is mounted immediately adjacent to the plane which a wrapper 8 should occupy before being introduced, with an article, into a pocket in a wrapping wheel by the devices described in Specification 326,831. The detector is coiled to form a hinge loop about a terminal screw 13 on an insulating block 12, and an adjusting screw 15 engages a second loop 14. The complementary part of the detector is constituted by the oscillating fingers 16, connected to a vacuum, which assist in drawing the wrapper into a pocket. If a wrapper is present, the parts 7, 16 do not contact and the machine works normally. If no.wrapper is present, contact is established as shown in Fig. 5, and a circuit is completed to energize an electromagnet 18. A hinged armature 19 is attracted into the position shown and rocks a switch-arm 21 so that contact is broken between the terminals 22, 23 and the machine drive is stopped. The detector circuit may be completed by contacts 25, 26 when the switch-arm is in the "in" position, and broken as shown in the " out " position. The switch-arm may be re-set by manually operable means. The detecting part 7 may comprise two insulated members adapted to be bridged by the member 16. In a modification, the degree of air pressure in the wrapper engaging fingers may be used to actuate the relay device through electrical or pneumatic means. A sensitive diaphragm or mercury balance is arranged to have a maximum displacement when the degree of vacuum is highest due to the effective engagement of a wrapper. If, however, the vacuum orifices are not closed by a wrapper the smaller displacement of the detecting means is used to cut out the drive and, if necessary, apply a brake.