FRAMING METHOD

Abstract: A method of joining members (1, 2) of a frame, and in particular mitre joints and picture frames. This invention provides a locking plate (3) bridging the two frame members (1, 2) and secured to one frame member (1) on one side, said locking plate (3) being provided with a hole (9) in the opposite side in which a cam pin (14) bearing against the other frame member (2) may be rotated, thus causing said other frame member (2) to be tightly drawn towards the one frame member (1).

Description: FRAMING METHOD TECHNICAL FIELD THIS INVENTION relates to framing and is more particularly concerned with the formation of so-called "mitre joints" and/or "butt joints" in a frame composed of, typically, four straight frame members. Specifically, the invention is directed towards a method of affixing two such frame members together so as to result in a mitre joint that is neat, firm, needs no further adjustment and is especially applicable to picture frames. BACKGROUND ART Ideally, the junction line between adjacent frame members of a frame formed by the use of mitre joints should take the appearance of a straight fine line bisecting the angle of the corner. Any inaccuracy in a mitred corner is immed- iately apparent upon inspection as the junction line may well take the form of a wedge-shaped gap. For this reason it is customary to prepare a mitred joint with care. Usually, a jig is used which provides a flat firm support for the frame members to be cut and has a guide slot for ensuring that a saw or guillotine, used to cut the ends of the members, is at the correct angle of 45° to the longit¬ udinal axis of the member being cut. If the ends of the members are accurately cut, a clean, precise mitre joint can be produced provided the members are correctly juxtaposed. The frame may be assembled by affixing adjacent mitred frame members together by nailing, screwing, glueing and the like. It is not uncommon to find picture frames the corners of which are not neatly jointed, although quite often the joint may be seen to have received further attention in an effort to produce the clean and pleasing appearance of a well-mitred joint. DISCLOSURE OF THE INVENTION It is an object of the present invention to provide mitre joints having clean, neat and pleasing appearance. It is a further object of the present invention to provide a jointing method whereby such mitre joints can be produced rapidly and easily. In accordance with the present invention, therefore, there is provided a method of making a mitre joint between two frame members in the same plane; characterized in that said method comprises the steps of; forming a recess in a mitred butt face of each frame member, said recess being so dimen¬ sioned as to be able to accommodate substantially one half of a locking plate adapted to bridge said mitred butt faces when said two frame members are placed in juxtaposition; and inserting a pin through an aperture in each said frame mem¬ ber and thence into a co-acting aperture in said locking plate, at least one said pin having a camming portion adap- ted to engage in a said co-acting locking plate aperture, rotation of said camming pin within a said frame member causing said locking plate to draw said mitred butt faces into close abutment. Preferably the locking plate is of circular configuration, perhaps an annulus or disc of metal or a suitable plastic material, and has its said co-acting apertures formed adjacent its perimeter, these apertures being diametrically opposed. Each recess may thus be substantially semi-circular so as to snugly receive therein a substantial half of the locking plate. Ideally, a said camming pin may well have an eccentrically- disposed spigot which constitutes the camming portion and is adapted to engage in a said locking plate aperture of an elongated configuration. Each recess may have that radius which is normal to the junction line between the frame members slightly greater than that which coincides with the said junction line; in a further variation each recess may be shaped so as to permit a degree of adjustment along the said junction line. BRIEF DESCRIPTION OF THE DRAWINGS Certain preferred embodiments of the invention will now be described, by way of example only and with reference to the accompanying drawings in which:- FIGURE 1 is an exploded rear view of a mitre joint according to the method of the present invention; FIGURE 2 is a broken-away view of a mitre end of a simplified frame member; FIGURE 3 is a corresponding side elevation but not broken away; FIGURES 4, 5 and 6 are views of a typical camming pin; FIGURE 7 is a broken-away view, similar to Figure 2 but of a second embodiment; and FIGURE 8 is a corresponding side elevation but not broken away; In the drawings, for the sake of clarity, the frame members are shown as being of simple rectangular cross-section but it will be appreciated that they will usually be profiled, wooden or metal so-called "moldings"; the metal may well be aluminium or an aluminium alloy, preferably fabricated by extrusion. MODES FOR CARRYING OPT THE INVENTION Figure 1 shows how two frame members 1 and 2 are joinable via a locking plate 3 so as to constitute a mitre joint. Each frame member 1, 2 has a mitred butt face, referenced 4 5 and 5 respectively, and routed into each butt face is a recess, respectively 6 and 7. These recesses are so dimensioned as to be able to accommodate substantally one half of the locking plate, as will be seen. Locking plate 3, which is adapted to bridge mitred butt DD faces 4 and 5 when frame members 1 and 2 are placed in juxtaposition to define a 45° mitred corner, is of circular configuration as a disc or annulus and, indeed, it may actually be a steel or brass washer. Diametrically opposed in locking plate 3 are a pair of apertures 8 and 9, one of 5 5 which takes the form of an elongated slot. For constructing a frame which is narrow, a small discoid locking plate, perhaps less than 20 mm in diameter, may be required, while a wide frame may need, say, a 50 mm diameter annulus. D _ From the back of frame member 1 an aperture 10 extends into routed recess 6, and from the back of frame member 2 an aperture 11 extends into routed recess 7. These apertures 10 and 11 are so positioned so as to align up with locking plate apertures 8 and 9 respectively when the three compon- 55 ents are fitted together to make a mitre joint. In the embodiment illustrated, the locking plate 3 is firmly affixed in frame member 1 by means of a pin (not shown) which is inserted through aperture 10 and thence into co-acting aperture 8 in the locking plate. The recess 7 is 1DC then pushed over the exposed half of locking plate 3 so that the larger aperture 11 aligns up with elongated slot 9, and a camming pin inserted; the construction of this camming will be described later herein with reference to Figures 4, 5 and 6 of the drawings. Figures 2 and 3 show a broken-away view of a mitre end of a simple frame member of rectangular cross-section. Frame member 1, which is essentially the same as that illustrated in Figure 1, has a semi-circular recess 6 routed into its mitred butt face 4; Figure 2 in particular shows frame member 2 broken away, the better to reveal recess 6. It has been found advantageous to make recess 6 of such a shape that its radius which is normal to butt face 4 - that is to say, of a length equal to that referenced 12 - is very slightly greater than that radius which coincides with butt face 4 - the length equal to that referenced 13. Turning now to Figures 4 to 6, the previously-mentioned camming pin, generally referenced 14, has a cylindrical body portion 15, of a suitable metal, provided at its head end with a slot 16 to enable it to be rotated by a screwdriver or other tool. At the other end of body portion 15 is provided an eccentrically-disposed spigot 17, ideally machined integrally with the body portion. Body portion 15 of the camming pin 14 is adapted to be rotatably accomm¬ odated within a frame member aperture in such a way that the spigot 17 will engage an elongated aperture of the locking plate. Rotation of camming pin 14 will thus cause frame members 1 and 2 to be drawn towards each other so as to bring their mitred butt faces into close abutment; in this way, a neat and firm mitred joint is ensured. Finally, figures 7 and 8 show a variation and again show a broken-away mitre end of a simple frame member of rectang¬ ular cross-section. This frame member, referenced 18, has, routed into its mitred butt face 19, a recess 20 shaped so as to permit a degree of adjustment along the junction line between frame members, this being brought about by what may be termed a tangentially defined extension 21 to the substantially semi-circular recess. Thus, if a set of frame members have minute variations in width, adjacent members may be fractionally adjusted to produce a perfect outer corner. However, by and large, apart from the described radial variation and the tangential extension, it will be appreciated that the recess snugly fits its associated locking plate half. It is to be further appreciated that the locking plate might be of any shape and initially may be loosely provided between the two frame members, two cammming pins being used to draw the frame members together. In yet another variation the locking plate is envisaged as being disposed externally of the members to be joined. INDUSTRIAL APPLICABILITY The present invention is. applicable to the production of any sort of framing, such as window framing for example, but particularly to picture framing in which the members to be drawn together may comprise quite completely-profiled "moldings". The apertures, as those referenced 10, 11 are provided in the rear face of the frame so as to avoid unsightly holes in the moldings when viewed from the front. Other variations, modifications and embodiments of the present invention as has been described above may well be possible without departure from the spirit thereof and without exceeding the ambit of the following claims.

Claims: WHAT IS CLAIMED IS: 1. A method of making a joint between two frame members in the same plane; characterised in that said method comprises the steps of; forming a recess in a butt face of each frame member, said recess being so dimensioned as to be able to accommodate substantially one half of a locking plate adapted to bridge said mitred butt faces when said two frame members are placed in juxtaposition; and inserting a pin through an aperture in.each said frame member and thence into a co-acting aperture in said locking plate, at least one said pin having a camming portion adapted to engage in a said co-acting locking plate aperture, rotation of said camming pin within a said frame member causing said locking plate to draw said mitred butt faces into close abutment. 2. The method as claimed in Claim 1 wherein said joint is a mitre joint" 3. The method as claimed in Claim 1, wherein said locking plate is of circular configuration, being an annulus or disc, and each said recess is semi-circular. 4. The method as claimed in Claim 1, wherein said co-acting apertures are formed adjacent the perimeter of said locking plate and are diametrically opposed therein. 5. The method as claimed in Claim 1, wherein said at least one camming pin is provided with an eccentrically- disposed spigot which constitutes said camming position and is adapted to engage in a said locking plate aperture of elongated configuration. 6. The method as claimed in Claim 1, wherein said locking plate is of circular configuration, being an annulus or disc, and each said recess is shaped so as to permit a degree of adjustment along the junction line between said frame members. 7. A method of making a mitre joint between two frame members in the same plane; characterised in that said method comprises the steps of; forming a substantially semi-circular recess in a mitred butt face of each frame member, said recess being so dimensioned as to be able to accommodate substantially one half of a circular locking plate adapted to bridge said mitred butt faces when said two frame members are placed in juxtaposition; inserting a pin through an aperture in one of said frame members and thence into a first co-acting aperture in said locking plate so that substantially one half thereof is firmly affixed within its associated recess; placing the exposed portion of said locking plate into the said recess in the other frame member and inserting a camming pin through said other frame member and thence into a second, elongated aperture in said locking plate, said camming pin being provided with an eccentrically- disposed spigot adapted to engage the said elongated aperture; and rotating said camming pin to cause said locking plate to draw said mitred butt faces into close abutment. 8. The method as claimed in Claim 6, wherein that radius of each said substantially semi-circular recess which is normal to the junction line between said frame members is slightly greater than that which coincides with the said junction line.

Inventors: WATSON BRUCE SAMUEL, WATSON, BRUCE, SAMUEL
Applicants: WATSON BRUCE SAMUEL, WATSON, BRUCE, SAMUEL
Application year: 1986
Main classification: F16B12
IPC codes: A47G1, F16B12