LAPPING MACHINE

Abstract: A machine for cutting timber (M) to form a half lap joint comprises a base (11), cutters (8), (9), and (10) mounted on the base (11) project beyond one side of the base (11), cutters (8), (9), and (10) rotate in a common vertical plane having their axis of rotation substantially parallel. Cutters (8) and (10) are opposed to one another and cut top and bottom face grooves optionally with sloping sides at an angle of 45<o>. The cutter (9) makes a straight groove on the edge which completes the half lap joint. Cutters (8), (9), and (10) are driven by a single drive. A carriage (15), slidably mounted on the base (11), and clamp (16) support the timber so that it can be moved to and from the cutters.

Description: LAPPING MACHINE THIS INVENTION relates to an improved lapping machine for cutting timber to form half lap joints. The machine of the present invention is particularly suitable for use with moulded timber such as that used in windows. In one form the invention resides in a machine for cutting timber to form a half lap joint comprising a base, a plurality of cutters mounted on the base so that they project beyond one side of the base, said cutters rotating in a common vertical plane and having their axis of rota¬ tion substantially parallel, a carriage adapted to receive the timber to be cut, and clamp means to hold the timber in place on the carriage, said carriage being slidably mounted on the base so that it can move towards and away from said cutters. The invention will be better understood by reference to the following description of one specific embodiment thereof shown in the accompanying drawings wherein:- Fig. 1 is a side elevation of one embodiment; Fig. 2 is a plan of the embodiment of Fig. 1; Fig. 3 is a side elevation (with guards and cutters omitted for clarity) of a second embodiment; and Fig. 4 is a front elevation of the embodiment of Fig. 3. As shown in Figs. 1 and 2 of the drawings an electric motor 1 is mounted on a base 11 on which is also mounted a cutter assembly 4 and a guide fence 12. Three cutters namely 8, 9 and 10 are mounted on one side of the cutter assembly with a shaft projecting through suitable bearings therein. The other end of each shaft is fitted with pulleys 5, 6 and 7 respectively which are in turn coupled to a pulley 2 on the motor by means of an endless belt 3. Preferably the provision is made for enable the upper cutter 8 to be moved towards or away from the lower cutter 10 by a short distance to accommodate for varying widths of moulding. The timber moulding M to be cut is mounted between the two guides 12 and held in place by means of a toggle clamp 16. The cutters 8 and 10 are shaped so that they produce a groove with sloping sides at an angle of 45°. It is a simple matter to feed the moulding clamped in position between the cutters so that it cuts a suitable groove in one face. A groove is cut in another piece of moulding on the other face. The two pieces of moulding are then lapped together. The machine eliminates a substantial amount of labour which is normally required to make up a window frame from many segmented pieces. In addition, it will be appreciated that the vertical and horizontal blazing bars are each of full length and each joint be¬ comes a half lap joint so as to achieve maximum strength. If desired the motor may be mounted directly on the cutter assembly. In the embodiment shown in Figs. 3 and 4 the frame of unit consists of two identical cradle members 31 and 32 joined by threaded tee bars 33 with appropriate spacers. An electric motor (not shown) is mounted on a base plate 34 which is supported on four small bearings 35 to allow it to move in the cradles to accommodate tilt adjustment effected through an adjusting screw 36. A work head assembly comprises an arm 37 and a mounting plate 38 pivotally mounted on the base plate 34. A fine adjustment screw 40 for adjusting the relative positions of the arm to the mounting plate is provided. The arras are locked in the desired position by a lock 41. Bearing assemblies 42 and 43 are provided on the outer end of the arm and the mounting plate whilst a third bearing assembly 44 is provided on the mounting plate in a position intermediate the assemblies 42 and 43. Cutters 45 are mounted on each of the bearing assemblies on one side of the arms whilst pulleys 46, 47 and 48 are mounted on the assemblies on the opposite side of the arms. The pulleys support an endless belt (not shown) passing around the pulleys and a pulley on the motor as in the first embodiments. The rear end of the arm 38 is pivotally connected to an R & F screw 49. Work tables 50 are supported on slide ' s 51 are supported on the frame on both sides of the work head assembly. The work to be cut is held in place by a sliding guide fence 52. An overhead guard (not shown) covers the cutting area.

Claims: THE CLAIMS defining the invention are as follows:- 1. A machine for cutting timber to form a half lap joint comprising a base, a plurality of cutters mounted on the base so that they project beyond one side of the base, said cutters rotating in a common vertical plane and having their ' axis of rotation substantially parallel, a carriage adapted to receive the timber to be cut, and clamp means to hold the timber in place on the carriage, said carriage being slidably mounted on the base so that it can move towards and away from said cutters. 2. A machine as claimed in claim 1 wherein two of the cutters are mounted on a mounting plate whilst a third cutter is mounted on the outer end of an arm adjustably mounted on the mounting plate. 3. A machine as claimed in claim 1 or 2 wherein the base comprises a pair of U-shaped cradle members joined by bars and a base plate supported on bearings to allow it to move in the cradles to accommodate tilt adjustment. 4. A machine as claimed in claim 3 wherein the cutters are mounted on a work head assembly which projects upwardly from the base plate. 5. A machine substantially as herein described with reference to Figs. 1 and 2. 6. A machine substantially as herein described with reference to Figs. 3 and 4.

Inventors: FOGLIANI UMBERTO CESARE, FOGLIANI, UMBERTO, CESARE
Applicants: FOGLIANI UMBERTO CESARE, FOGLIANI, UMBERTO, CESARE
Application year: 1985
Main classification: B27C5
IPC codes: B27F1