Joint member

#The present invention relates to a threaded joint member for providing a tight abutment connection of two objects such as two pieces of a K-D(knock down) type furniture assembly, decorative pole assembly or the like.

#An example of the field of application of the present invention can be found in U.S. Pat. No. 3,437,059, issued to R. W. Stoner et al. on Apr. 8, 1969. Another example of the application of the present invention is my Canadian Pat. No. 969,908, issued June 24, 1975 and referring to a lamp pole assembly. It will be appreciated that the field of application of the present invention is not limited to the above two examples.

#In the above art, the most usual way of connecting two members is the use of a spring member introduced between abutting ends of two connected pieces, such as shown in the above mentioned U.S. patent, the drawback of such joint being in its failure to provide a rigid enough assembly for practical purposes. The rigidity of the joint shown in my Canadian Pat. No. 969,908 is improved by replacement of the spring members with a rigid wooden threaded connector which is screwed into end recesses of the abutting pieces to form a lamp stand or the like. However, the latter type of joint is almost impossible to use when the abutted pieces are of square, rectangular or polygonal cross section as in such cases it is vital that the surface planes of one such polygonal piece be parallel with their respective counter-planes on the surface of the other abutting piece. Therefore, the joint employed in this type of assemblies of furniture or the like has thus far been either a glued dowel joint such as the one disclosed in U.S. Pat. No. 3,405,592 issued Oct. 15, 1968, or a relatively complex screw-type joint of the kind disclosed in Canadian Pat. No. 786,010 issued on May 28, 1968 and employing a deformable insert member associated with a threaded member, which, in turn, is actuated by a special key to expand the insert member in establishing a connection between two tubular pieces.

#Several embodiments of the present invention will now be described in greater detail with reference to the accompanying drawings in which

#FIG. 1 is a partial perspective view, partly in section, showing a K-D coffee table top and a part of one leg thereof, as assembled, with two different types of the joint of the present invention being shown in this particular figure;

#FIG. 2 is a longitudinal section of another embodiment of the joint member according to the present invention;

#Turning now to FIG. 1, a corner portion of a coffee table is shown including a flat top 1 and a portion of a leg consisting of a plurality of leg sections 2, 3. It will be observed that the objects 1 and 2 have to be in a tight abutment connection with each other. Similarly, the objects 2 and 3 are joined with each other in a tight, abutment manner, without the use of a glue.

#Secured to the top 1 by means of a screw 4 is a cylindrical sleeve 5 which is made of hardwood. The sleeve 5 is secured to the top 1 solely by axial pressure exerted by the head 6 acting on the sleeve 5 through a washer (not shown). It will be appreciated that without the use of a glue, the sleeve 5 can be turned about the shank portion of the screw 4 even on tight securing of the sleeve to the top 1, providing that sufficient force is exerted on sleeve 5 to overcome the frictional axial force of the screw head 4, holding the sleeve 5 in place.

#The outer surface of sleeve 5 is provided with a power transmission type screw thread 7, the thread 7 being of the same size as the inner thread 8 machined in a central, axially extending bore of the leg section 2. In other words, the sleeve 5 has its outer surface provided with a thread 7, said thread 7 being adapted to be received in an inner thread 8 provided in one of said two objects 1, 2.