Patent GB-342259-A (GB)
Title: Improvements in or relating to envelope machines
IPC: B31B19/00
Filed: 1929-07-23
Abstract: 342,259. Envelope machines. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(Tear & Pull Envelope (Development), Ltd.; A.M.L. & F. Building, Creek Street, Brisbane, Australia.) July 23, 1929, No. 22655. [Class 94 (ii).] Relates to an envelope machine of the type in which a thread or cord is placed and secured in a folding crease of each envelope, the thread being drawn from a source of supply, gummed or treated with other adhesive prior to being positioned in the envelope folding crease and severed to the correct length. The apparatus is built in to a step-by-step delivering envelope machine and associated with the dryer. The formed envelopes are carried by ; a chain A3 which is driven in step-by-step fashion by a sprocket A5, ratchet A7, rod A8, and eccentric A9, the latter being driven by the main driving shaft A10; the actuation of the chain being synchronized with the delivery of envelopes from the making portion of the machine. During the passage beneath the dryer the envelopes are retained in position by guides A14. Secured to the shaft A10 is a cam B which oscillates the lever B1 about its pivot B2 thereby reciprocating a carriage B3 in guides B4. The carriage B3 carries a thread pick-up B5 and is formed with a cam track C4. The pick-up, Fig. 16, moves back and forth across the path of the envelopes and between the body and flap of each envelope, the links of chain A3 being notched at A4 to facilitate this movement and consists of two jaws B6, B7 normally held together by a spring B9, acting through a stem B8, but the jaws are opened to pick up the thread when the pick-up has approached the end of its forward movement by a rigid stop engaging a projection B10. The thread carrier, Fig. 12, is provided with an arm C2 and roller C3, engaging the cam track C4 by which the device is given partial rotatory movements, and comprises a vertical spindle C carried in fixed bearings C1 about which it is partially rotated. The spindle carries two bosses C5, C6, between which the pick up is projected at the forward end of its stroke. The boss C5 carries a thread guide sheave C7, kept seated by spring pressure, and the other boss C6 carries a thread gripping jaw C10, also seated by spring pressure. A disc C13 is slidably attached to the e spindle and is raised periodically , by , a cam C15 through tappet C16, slide J2 and lever C14. The cam C15 has a double rise so that on rotation it first raises the guide sheave C7 to raise the level of the thread guided by the same and then, due to the lost motion space C18, the jaw C10 is raised to free the end of the thread. The operation of the carrier is as follows:- When the pick-up B5 moves over to pick up the thread the carrier receives a part rotation from its cam track C4 moving the piece of thread held between C7 and C10 to a position at right-angles to the line of travel of the pick-up. The thread is now below the level of the jaws B6, B7 and cannot be picked up until given a lift by the cam C15. The thread is then gripped and the jaw C10 opens to release the end of the thread which is then pulled across the machine, by the returning pick-up B5. As the thread is pulled across, the carrier gets a partial rotation to move parts C7 and C10 out of the path of the gummed thread and at the end of the stroke of the pick-up B5 another partial rotation brings the jaw C10 into position against the thread to grip it before it is severed. The thread carried by a reel &c. through a tensioning device is led over a gumming bath D. In the bath is a gumming bar D1, the width of the envelope, pivoted at D2; and it. is caused to rise up from the bath and contact with the thread as it is stretched to the jaw C10, by cam D7, lever D6 and rod D5. Presser feet D4, situated on each side of the bath and connected to bar D1 by links D3 press the thread firmly into contact with the bar. To press the gummed thread into place levers E, with pressing fingers. E1, are provided operated by cams E2 and tappets E3, the pressure being eased just before the fingers are lifted away. The thread, now in position, is severed at both ends by snips G, mounted on levers Gl, operated by cams G2, the snips being connected. to links G4, pivoted to a fixed point G5. To avoid the soiling of subsequent envelopes by contact with severed pieces of gummed thread carried by the chain which may have been deposited thereon in the event of an envelope not being in position, the following safety device is provided. At the end of shaft F is a cam H which rocks a lever H1 through a tappet H2. The tappet is kept in contact with the cam by a fairly strong spring H7 but the lever H1 is actuated by a light spring H6, the tappet being capable of sliding through the lever H1. The lever H1 is carried by a shaft H3 to which are attached a second lever H4, with an inverted V groove H5, and a sector H8 with a cam face H9. Bearing against the sector H8 is a roller J attached to a lever J1 at the other end of which is attached the slide J2, previously mentioned, with an orifice J3. Assuming an envelope to be in place: When the groove H5 bears on the top of the envelope, the lever H4 will be arrested and therefore the cam H9 will not move the roller J; the tappet H2 will slide through the lever H1 and the light spring H6 will be compressed. The action of the sliding disc C13 is then normal i.e. through cam C15, tappet C16, slide J2 and lever C14. If an envelope is not in position : The groove H5 will continue to advance and therefore the cam H9 will move the roller J and the slide J2. In doing so the orifice J3 is brought above the tappet C16 and the lever C14 is not moved. The thread stretched between the sheave C7 and jaw C10 is maintained below the path of the pick-up which does not, therefore, function.