US 2151880 A
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March 28, 1939. H. WIEDERKEHR 2,151,880 VENEERING PRESS` Filed March 25, 1957 2 sheets-sheet l fs 24 ,2+ la -23 4 2a i 9 i H Il I/ 20. '7 4 5 2f 1 11 12 1o L a3 l ff Mmmm March 28, 1939... H. WIEDERKEHR 2,151,880'
' VENEERING PRESS Filed Marchk 23, 1957 v 2 sheets-sheet 2 f4 7 is f4 "2 v 'Janna/mad,
Patented Mar. 28, 1939 UNITED STATES` PATENT oFElcE VENEERING PRESS land Application March 23, 1937, Serial N0. 132,650 in Switzerland July 31, 1936 1 Claim- The present invention relates to aveneering press particularly for irregular surfaces and relates to that kind of presses, where the veneer is applied by means of a iiexible, impermeable cover 6 vput under hydraulic or pneumatic pressure con-` tained in a hood covering the work piece.
The invention consists in lmechanical means for lifting off said hood and in means for heating A cut oif valve 22 controls the feeding of the cylinders I5 with compressed air and an air relieve 10 the table receiving the work piece. l The annexed drawings represent one embodiment of the invention. 'I'here is:
Fig. 1 a cross section, Fig. 2 a longitudinal section, Fig. 3 a diagram of the pressure gas conduit l and Fig. 4 a detail of the connection between pressure gas conduit and inlet of the hood.
According to Figures 1 and 2 a rectangular .25 to a power current system. Plate 4 is coated on its upper side with a heat insulating layer 5 and table plate 2 has a grooved ledge 6 running all around its borders into which t the bulbed edges of a hood l of semi-circular cross section clamping .fast thereby a flexible impermeable cloth 8,
preferably of rubber, which closes the open bottom of said hood. The edges of the cloth -projected to the outside of the hood are suspended there by means of helical springs 9.
As means for lifting the hood from the table plate guide pieces I9 are attached to its two ends. A
Said guide pieces are guided in verticalguide rai-ls I8 fast to the table plate and are controlled by piston rods I'l the pistons I6 of which are fitted 40 to vertical cylinders I5 attached to the stand I. The piston rods are formed as racks meshing with pinions 20 fast to rail 2I for the purpose of securing the parallel 'displacing of said guide pieces. Pins 23 secured to these guide pieces are adapted to be caught by hooks 24 hinged to the ends of said guide rails When the hood has been lifted into its uppermost position. This prevents any accident to the workmen. Before lowering the hood again said hooks must be pushed aside by hand. l
In the hollow space of the stand and underneath plate 4 a device for-producing compressed and heated air is arranged on a bracket of said stand.
An electro-motor I0 if. coupled to an air comform piece.
pressor I I and feeds the air into a collecting tank I2 for the purpose of providing the hood 1 and the cylinders I5 with compressed air. The conduit from the tank to the hood passes through a heating device I3 as is shown in Fig. 3 and is 5 controlled by a cut off valve I4 and by a nonreturn valve 3l preventing an escape of compressed air from the hood into the tank. Another valve 22" controls the outlet of the. air enclosed between the pistons I6 and the cut off valve 22. when the hood has to be lowered.
Since hood 'I is movable, while tank I2 remains stationary, the compressed air conduit between 15 the two cannot be rigidly connected. The connection is only established in the operative position. According to Fig. 4 the inlet pipe.30 of the hood lits in the .Working position of the hood with a conical fit into the funnel shaped end of 20 the delivery pipe I 4 of the tank.
According to Fig. 1 the hood possesses also the ordinaryg'safety devices. These are all arranged lon one of the end faces of the hood, to wit, a 'IT-fitting 25 communicating on one side with a 25 vent controlled by a cut off valve 25 and on the other side with a safety valve 2-8 and a manometer 26 and a thermometer 2T. Also the air tank I2 possesses a safety valve not shown.
Besides there are vents 29 provided in the ledge 30 6 for the escape of the evaporated humidity of the glue and for the air remaining between the rubber' cloth and work piece.
The press is operated as follows:
The hood 'I having the rubber cloth 8 attached 35 to it by means of the springs 9 is suspended in the hooks 24. Then the form piece withA the veneer plate put on and having adhesive disposed between them is placed upon the table plate and the hood is lowered vby pushing the hooks 24 aside 40 and cautiously opening the air relieve valve 22".' The hood is lowered until its edge rests within the grooves of the ledge and pipes 30 and I4 have become joined. Now the compressed air collected. in tank I2 and heated in device I3 is admitted by 45 opening the valve I4' and the pressure inside the hood increased until the veneer plate, softened by the heat, has been fully applied tightly to the Inv this state .the press is left until the glue has been hardened. This hardening will 50 be accelerated by heating-the table plate 2. After the hardening of the glue the hood is removed again by opening first valve 25 and closing valve 24' to let escape the pressure Within the hood, whereupon valve 22' may be opened to lift off 55 van- 2 I I p 2,151,880
10 vents between it and the plate, a, hood having its edges fitting into said ledge, a flexible impermeable cloth held fast between said edges and the ledge, and means for raising and lowering said hood, said means comprising vertical guide rails, fast to the table plate, .guide pieces fitting said guide rails and fast to the hood, vertical pneumatic cylinders open at the top and cooperating pistons with rods attached to said guide pieces.