Patent GB-1516286-A (GB)
Title: Article wrapping machine
IPC: B65B9/06
Filed: 1976-10-14
Abstract: 1516286 Wrapping articles R F ANDERSON 14 Oct 1976 [2 Jan 1976] 42764/76 Heading B8C [Also in Division B5] A machine for wrapping articles X in a web W longitudinally folded around the articles X includes endless inlet and outlet conveyers 136, 42 to support the articles on the web, an upper conveyer 35, lower and upper jaw assemblies 47, 57 on the conveyers 42, 35 to grip and feed the folded web W, the conveyers being driven through a drive cycle at the same linear speed to advance the jaw assemblies through a distance equal to their interspacing, and a mechanism to press an opposed pair of jaw assemblies together to clamp the web during an adjustable portion only of the cycle so that the web is advanced by an adjustable amount less than the jaw interspacing dependent on the article size. The pressing mechanism may comprise a fixed rail 83 and an adjustable rail 85 which press the upper jaw assemblies against the lower assemblies. A cam rail 88 lifts the upper assemblies as they leave the rail 85. Alternatively there may be just a fixed pressing rail acting on the upper assemblies and the upper conveyer is pivoted upwardly to separate the jaws. The web is transversely sealed and severed between adjacent articles by a member 101 movable, by crank arms 105, in a closed loop, in between spaced jaws 47a of each lower assembly 47. The member is heated and comprises a pair of sealing surfaces separated by a central serrated cutter (112) having beveled side blades. The member is vertically adjustable so that the sealing surfaces can be pressed against surfaces (57a) of an upper assembly if the web is of coated paper or foil. If the web is of thermoplastics film the member is lowered a little and the side blades form bead seals.  The web is folded longitudinally flat on itself, and fed between spaced fingers (166b, Fig. 6a, not shown) while a separator finger (167) extends between the folds. The web passes about an article guide shoot (169) of adjustable width into which articles drop from a conveyer. An ejector pushes each article out of the shoot on to the wrapper and a releasable stop (191) locates the article thereon. The inlet conveyer 136 is arranged to be driven during engagement of the jaw assemblies and comprises two sets of transverse slots 141, 142 alternating with one another. The sets carry clamps (141b), 142b which engage opposite sides of the web to hold the articles. The two sets of slots and thus the clamps are transversely relatively movable. Cam rails move the slots transversely to move adjacent clamps apart to receive articles on the web. Springs which interconnect adjacent pairs of slots then urge the clamps against the web. If the web is of plastics film rotary brushes (201a, 201b) are used to overlap the opposed edges of the web and hot air from a nozzle 211 form a longitudinal heat seal. Air is only supplied to the nozzle during movement of the wrapper. However, if the wrapper feed is stopped for more than a set time, the nozzle is raised and air is re-supplied to prevent overheating of the heater. If the web is of coated paper or foil ploughs move opposed edges of the web together and stationary heaters form a longitudinal fin seal. The machine may have a plurality of wrapping lanes side-by-side.