GB1054881A - - Google Patents

Abstract

1,054,881. Woodworking. G. GIESECKE, G. GIESECKE, K. GIESECKE, and H. GIESECKE, [trading as HUBEL & PLATZER]. Feb. 23, 1965, No. 7859/65. Heading B5L. A method of connecting end-toend two or more workpieces having a dovetail or similar configuration on their ends by means of an adhesive substance comprises giving the workpieces a continuous feeding movement and pressing the workpieces together by temporarily delaying the feeding movement of a forward workpiece relatively to the following workpiece or workpieces by a braking means which participates in the delayed feed movement. In apparatus for carrying out the method, a stand 1 is provided with feed rollers 2 for advancing the workpieces which have their ends coated with adhesive to a counter-pressure slide 4 engageable with each workpiece by the action of a hydraulic or pneumatic pressure cylinder or cushion 9 on a counter-plate 20. The cushion 9 is controlled by a valve 8 in a circuit having a switch 7 and a break switch 11 which is operated when the movement of the counter-pressure slide by the workpieces has caused a predetermined pressure to be reached in a pressure cylinder or cushion 10. A pair of condenser plates 5 are disposed between the feed rollers 2 and slide 4 and are connected to a highfrequency circuit a, b having a current relay 6. When a joint having adhesion passes the plates 5, the change in dielectric causes the current relay 6 and an amplifier to respond and close switch 7 so that valve 8 supplies fluid pressure to cushion 9 to cause the slide 4 to apply a counter pressure to the movement of the leading workpiece thus pressing the glued ends of the workpieces together. The slide 4 is moved by the workpiece against the pressure in the cushion 10 until such time as the pressure therein operates the break switch 11 to actuate the valve 8 and release the pressure in the cushion 9 thereby releasing the slide from the workpiece. The join then passes between the elements 14 of an infra-red heater 13 or the like and through a cooling zone 15. A rotary condenser 12 is provided for adjusting the capacity of the plates 5 for various workpieces. The cushion 10 may be in the form of a rubber or mechanical spring and the switch 11 may be a mechanical pull switch. For workpieces which do not require high pressing together pressures, such as strips having a small cross-section, the counter slide 4 and plates 5 are rendered inoperative and the forward workpiece has a counter pressure applied by a device 16 having rollers 19 or a shoe movable by a screw 18 or fluid pressure device to press the workpiece against the stand 1.