US2614302A - Joint for furniture construction - Google Patents

Description

@cih 2, lgsz H Et JOHNSQN JOINT FOR FURNITURE CONSTRUCTION Filed March 16, 1949 42W 36 K a 15W il fw@ W,

'the bottom.

Patented Oct. 21, 1952 JOINT FOR FURNITURE CONSTRUCTION Howard E. Johnson, South Ashburnham, Mass., assignor to W. F. Whitney Company, Inc., South Ashburnham, Mass., a corporation `ofv Massachusetts Application March y16, 1949, Serial N0. 81,685

2 Claims.

rIhis invention relates to furniture construction and especially to the formation of concealed joints in articles of furniture.

The principal objects of the invention are to provide an improved mortise and tenon joint for furniture which is of such construction as to afford a concealed joint; which will allow contraction and expansion of the joined parts without destruction of the joint; which provides for a stronger joint and for easier assembly ofthe parts; and which is materially less expensive to manufacture both from the standpoint of economizing in time and material. Other and irnportant aspects of the joint will appear hereinafter in connection with the description thereof.

In accordance with this invention where two members, for example structural members of furniture, are to be joined togetherV in abutting relationship by a mortise and tenonjointone of the members has a mortiseor open groove rabbeted or otherwise formed in itsr surface' extending inwardly from one of its edges, the'inner end of which terminates short of any other edge. The greater portion of this groove has spaced parallel side walls substantially at right angles to Near the inner terminal portion, the groove has re-entrant sidewalls and an end wall making acute angles with'the bottom the end wall being of generally semicircular s'hape. The abutting edge ofthe other member constitutes a tenen andV has locking and bearing portions extending therealong for Aengagement with the groove, the former having sloping walls mating with the re-entrant vside and end walls of the terminal portion of the groove and the latter being of rectangular crosssection and having a free-sliding iit in that part of the groove having the parallel walls. The locking portion is set back from the end of the edge with which it is associated and lwhen engaged withinr the re-entrant walls of the groove and brought into abutting engagement with its re-entrant closed end constitutes positioning means which controls the position of the members, this preferably being predetermined to bringthe exposed edges of the members flush with each other. Av binding material is employed to x the members in their assembled position, in the form of an adhesive, cement or the like applied solely to the locking portions of the mortise and teno-n While the entire supporting protions of the mortise and tenon are devoid of a binder and hence free to come and go relative to each other due to expansionor contraction of the members.

The invention will now be described in greater v2 detail with reference tothe accompanying drawings wherein: 1

Fig. 1 is an isometric fragmentary viewof an end portion of a piece of furniture embodying the improved joint construction showing a case end and several partition members;

Fig. '2 is a Vertical elevation of the inside of the case end showing the mortises for the top, front and rear frame rails and a mortise for one of the intermediate partition members;

Fig. 3 is a plan view of a fragmentary portion of the top edge of the case end shown in Fig. 1;

Fig. 4 is a vertical section on the line 4 4 of Fig. 2;

Fig. 5 is a vertical section on the line 5-5 of Fig. 2;V

Fig. 6 is a'vertical section on the line 6 5 of Fig. 2; l

Fig. 7 is a fragmentary plan view of a partition member showing a front and side rail and the construction of the novel tenon at the lateral edge of the member;

' Fig. 8 is a bottom plan view of Fig. 7;

Fig. 9 is a top plan view of an assembledV case end and partition member, the case end being in section in a horizontal planesubstantially in the surface of the partition member;

Fig'. 10 is 'a section on the line IU-l of Fig. 9; and f l Fig. 11 is a section on the line ||ll of Fig. 9.

In the manufacture of furniture, particularly custom-built furniture, for example bureaus, desks, bookcases and other articles of furniture', it is desirable to' secure the component parte, that is for example, the' case end, yframe rails and partition frame members with concealed joints, that is, jointvsywhich are not visible on the -face or other normally exposed surfaceV of the furniture. For the purpose of illustration only the novel joint'is shown therein as used in the construction of a bureau, a fragmentary portion at one end thereof being shownV in'Fig. l1 wherein there is a vertical casev end Il) having at its 1ower edge spaced supporting legs I2,.t his case end being joined to a corresponding case end (not shown) spaced therefrom by top, front and back yframe rails M-M and intermediate vertically spaced partition members IG-I' Which afford spaces in which may slide drawers. The front and rear frame rails at the top of kthe case ends are joined thereto by mortise and tenori joints I8, only one of which is shown herein. The mortise I1 is rabbeted or otherwise formed in the inner face of the case end by cutting in- Wardly from the top edge of the case end and at a point spaced from the vertical edge thereof and is of dovetail cross section (Fig. 3). The tenon I9 is formed at the end of the rail and has a corresponding dovetail construction which mates with the mortise. With the foregoing construction the joint is concealed except as seen from the top of the case end and since a top Will be placed thereon the joint will be completely concealed in the finished article.

The intermediate partition members I8 include front and back horizontal frame rails 20 extending across the front and rear vof the article from case end to case end and horizontal forwardly and rearwardly extending Vside frame rails 22-22. The rails 20-20'- and V2'2---22 are joined in conventional manner by tongue and groove joints to form a substantially rectangular frame Within which is placed and held a dust bottom 24, the latter being set into the frame with its edges situated in grooves 26 formed in the inner edges of the rails 20-20 and 22-22.

In accordance with the invention `the intermediate partition members I6 are secured in vertically spaced relation so that the exposed edge surfaces 28 of lthe front frame rails 20 will be flush with the forward vertical edge surfaces 30 of the case end members I0. This is accomplished herein by rabbeting horizontal, vertically spaced mortises or grooves 34 (Fig. 2) ineach case end. Each mortise has an open or entrance end 34 at the rear 'edge 32 of the case end and extends therefrom forwardly toward the front edge 30 terminating in a .closed or blind end 44 at a predetermined distance from the front edge 30 and has a locking portion which serves to unite the parts and a supporting portion fwhich serves to carry the load. The supporting portion 36 constitutes the major portion of the mortise, is of substantially rectangular cross section (Fig, 4) and has a bottom 38 andvertically spaced parallel side walls 40. The locking portion 42 is situated at the forward end of the mortise and has, as shown in Fig. 45, a flat bottom 38 forming a continuation of the bottom 38, reentrant side walls 42 and an end wall 44' inclined inwardly from the bottom and the parallel sides 40, the end wall being semicircular. Ihe supporting portion 38 ofthe mortise is made wide enough to receive the lateral edge of the intermediate partition member I6 therein with a freesli'cling fit, that is vwith sufficient clearance so that swelling and shrinking ofthe parts will not cause binding. Alternatively if a narrow mortise is desired, the lateral edge of the intermediate portion may be rabbeted off on one or both sides to fit freely into the mortise.

'Ihelateral edges of the intermediate members constitute tenons for engagement with the aforesaid mortises, each of which is divided into two portions, a locking portion and a supporting portion for engagement with the locking and supporting portions thereof. The locking portion is formed by rabbeting each end of the front rail 20 to provide a dovetail tongue having sloping front and side walls 52 and 52 corresponding in inclination to the reentrant walls 42 and 44'. ns illustrated in Fig. 8, the inclined front wall 52 of the locking portion is spaced from the front edge 28 of the rail a distance commensurate with the spacing of the inclined wall 44 at the end of the mortise from the front edge 30 of the case end so that when the members are assembled the surfaces 28 and 30 will be flush. It is to be understood, however, that the surfaces need not necessarily be flush 4 with each other but that they may be situated in any desired relation to each other. The end or edge of the locking portion is planed off so that it is shorter than the corresponding edge of the supporting portion 60. The supporting portion 68 is substantially rectangular in crosssection, having parallel surfaces which may be the normal top and bottom surfaces of the side rail or may be cut into the surfaces thereof by rabbeting to make this portion thinner if the mortise is of smaller dimensions.l In any event, the supporting portion 60 should be thin enough to afford a free fit into the mortise. A notch 58 is cut in the supporting portion 60 behind the lockingv portion to provide a clearance space for the junction between the rectangular and reentrant portions 3B and 42 of the mortise.

To assemble the parts adhesive is applied to the reentrant walls 42 and 44 of the mortise and to the inclined walls 52-52 of the tenon, the partition member I8 is placed substantially at right angles to the surface of a case end I0 with its forward edge 28 at the rear entrance to the mortise 34, and is then slid along the mortise until the front wall 52 is engaged with the closed reentrant wall 44 of the mortise. It is to be observed that since the inclined walls 52 of the locking portion 50 are set back from the surface of the supporting portion 60 and that it is not as long as the portion 60, no part of the locking portion 50 rubs against the bottom or walls of the rectangular portion of the mortise, and hence, when the tenon is entered into the mortise, the glue appliedY to the locking portion will not be scraped off onto the bottom or walls of the mortise andy be llost or effect cementing where it is not desired. In this connection it is important that no glue be applied to any part of the side walls or bottom of the mortise in the supporting portion thereof.

Important aspects of the foregoing construction are that the parts may easily be assembled and will interlock so as to hold their respective positions during hardening or setting of the cementing` material without employing clamps; that a positive interlocking of the parts is effected by engagement of the locking elements which prevents separation of 'the parts even though the cement may ultimately dry out to such an e'xtent as to become ineffective; that the cemented part of the joint is comparatively small so that expansion therein is comparatively small and hence there will be little opportunity for unequal expansion of the joint and possible disruption thereof. The greater part of the joint will be free to come and go with weather conditions and hence will not disturb or distort the article as a whole.

It is to be understood that the present disclosure is for purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

l. In an article of furniture a joint connecting two parts in abutting relation, without interposition of adjunctive elements, characterized in that one member has formed in it a mortise of given depth extending inwardly from one edge and terminating short of any other edge, a major portion of rsaid mortise being of rectangular cross section and the remainder near the terminal end having` inclined re-entrant walls, that the other member has at its abutting end an integrally formed tenon, a portion of which is of rectangular cross section and is slidably engaged Within the rectangular portion of the mortse and another portion of which has a dovetail cross section, the inclined walls of which are the converse of that portion of the mortise having the re-entrant Walls and is situated therein and a body of bonding material uniting the inclined walls of the dovetail portion of the tenon with the inclined Walls of the mortise, said rectangular portion of the mortise and tenon being free of bonding 10 material and free to come and go relative to each other.

2. A joint according to claim 1, wherein the extremity of the dovetail portion or the tenon terminates short of the plane of the bottom of 15 the mortise.

HOWARD E. JOHNSON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PAILNTS Number Name Date 24,361 Smith June 7, 1859 115,725 Frayer June 6, 1871 260,703 Moore et al. July 4, 1882 1,378,197 Schwab May 17, 1921 FOREIGN PATENTS Number Country Date 659,522 France Feb. 5, 1929

Images