Patent GB-312381-A (GB)
Title: Method of producing buckets, casks, and like vessels from pressed wood or plywood
IPC: B27D1/08
Filed: 1928-02-17
Abstract: 312,381. Homey, G. Feb. 17, 1928. Buckets and pails ; bodies; bottoms.-Relates to the manufacture by pressing operations of buckets and similar vessels provided with dished ends or bottoms and constructed of plywood or the like material. Fig. 1 shows one form of apparatus for the production of vessels of conical shape. The parts comprise a mould 1, a plunger 2, and a series of radially movable clamping blocks 3. These blocks, which are adapted to press the down-turned edge of the bottom 20 against the peripheral wall of the vessel, are connected by and radially movable with respect. to a ring 5 which fits around a central cylindrical guide 7. The lower faces of the blocks have extensions 8 resting on a vertically movable ring 10 supported upon springs 11. To the extensions 8 are pivoted links 12 connected to slide-blocks 13 formed with cylindrical parts 14 which fit into cavities in the guide 7 and are consequently radially adjustable by movement of a conical ended bolt 16 the head 17 of which is threaded to engage in the upper part of the central cavity. The parts to form the wall of the vessel-for example two half parts 4-being inserted in the mould, the bottom 20 is placed over the clamping- blocks 3 and the plunger moved downwardly. The axial pressure imposed on the blocks 3 causes them to move downwardly and consequently also outwardly thus pressing the downturned edge of the bottom against the wall parts 4 and effecting a tight fit. The operation being completed the springs 11 raise the finished vessel from the mould and allow it to be readily removed. Groove-like recesses are provided in the mould to enable the meeting edges of the parts 4 to be covered by strips 21 (see also Fig. 3), the shoulder 22 of the plunger being formed to co-operate. Fig. 5 shows the essential features of a construction for the production of cylindrical vessels composed of plywood &c. sheets a with covering strips c and a dished bottom b. The device comprises segmental inner and outer annular press-moulds d, e, received within a casing g the segments of the inner mould being adapted to be forced apart by a conical plunger f, while those of the outer mould are maintained pressed together by the press-head h to which the plunger is connected. The plunger has fan-tail ribs i which engage in the grooves formed by the juxtaposed segments of the mould d and engage projections k on the head of the mould to withdraw the parts when the plunger is raised on the completion of the operation. With the head h raised the parts of mould d fit together and those of mould e are forced apart owing to the slight raising of the mould by the action of an ejector m. The wall parts c, a, being inserted, the press-head and plunger are depressed, to consolidate the wall parts and the bottom. The clamping blocks for pressing the turned-down edge of the bottom against the walls are forced apart by upward movement of a conical mandrel o and are retracted after withdrawal of the mandrel by the raising of a ring p of conical formation engaging correspondingly shaped faces of the blocks. Fig. 6 shows a construction in which the outer mould comprises a stationary block n and a radially movable clamping block r which can be pressed against the inner mould f by means of an hydraulic cylinder and plunger s. Below the bottom, means (not shown) are provided for pressing out the edge thereof as previously described. In such a construction both the outer mould parts may be movable by hydraulic or other means. In any of the constructions the plunger and bottom support may be of hollow construction and heated by steam.