U.S. patent number RE30,154 [Application Number 05/845,256] was granted by the patent office on 1979-11-20 for joining.
This patent grant is currently assigned to Bose Corporation. Invention is credited to Arthur B. Jarvis.
United States Patent |
RE30,154 |
Jarvis |
November 20, 1979 |
Joining
Abstract
A joint is formed by pushing a grooved tenon into a
dovetail-shaped mortise containing a barbed wedge such that the
wedge is forced into the tenon groove, thereby spreading the tenon
to the dovetail shape of the mortise and anchoring the barbs into
the tenon, thus securing the joint and preventing the tenon and
mortise from separating.
Inventors: |
Jarvis; Arthur B. (Andover,
MA) |
Assignee: |
Bose Corporation (Framingham,
MA)
|
Family
ID: |
27110168 |
Appl.
No.: |
05/845,256 |
Filed: |
October 25, 1977 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
719942 |
Sep 2, 1976 |
04042307 |
Aug 16, 1977 |
|
|
Current U.S.
Class: |
403/290; 403/277;
403/381; 403/248 |
Current CPC
Class: |
F16B
12/04 (20130101); E04F 2201/041 (20130101); F16B
2200/40 (20180801); Y10T 403/535 (20150115); F16B
2200/30 (20180801); Y10T 403/4924 (20150115) |
Current International
Class: |
F16B
12/00 (20060101); F16B 12/04 (20060101); F16B
002/14 () |
Field of
Search: |
;403/381,290,248,251,249,409,297,277,268,267 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1045292 |
|
Jun 1953 |
|
FR |
|
22861 |
|
Oct 1900 |
|
CH |
|
Primary Examiner: Kundrat; Andrew V.
Attorney, Agent or Firm: Hieken; Charles
Claims
What is claimed is:
1. A joint comprising,
a first piece of material having a projection with a groove,
a second piece of material having a slot embraced by angled walls
with the width of the slot opening slightly greater than the width
of said projection and less than the slot width at its base,
and wedge means located within said slot and said groove, for
expanding said groove and urging said projection into engagement
with the walls beside said slot,
said wedge means being formed with a slit having an opening
adjacent to the base of said slot.
2. A joint in accordance with claim 1 wherein said wedge means is
formed with barbs on each side for engagement with inside walls of
said projection beside said groove.
3. A joint in accordance with claim 1 wherein the wedge means slit
is of triangular cross section with the triangular base at the base
of said slot.
4. A joint in accordance with claim 3 wherein the triangle height
is substantially 70% of the wedge means height. .Iadd. 5. A joint
comprising,
a first piece of material having a projection with a groove,
a second piece of material having a slot embraced by angled walls
with the width of the slot opening slightly greater than the width
of said projection and less than the slot width at its base,
and wedge means located within said slot and said groove and having
means defining a flat surface engaging the base of said slot for
expanding said groove and urging said projection into engagement
with the walls beside said slot,
said wedge means being formed with barbs on each side for
engagement with inside walls of said projection beside said groove
and being sufficiently resilient so that the span across said barbs
is reduced as said wedge means expands said groove and urges said
projection into engagement with the walls beside said slot.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates in general to joining two pieces of
solid material and more particularly concerns a novel joint that
may be rapidly and economically established to form a permanent
secure connectin between two parts. The invention is especially
useful in joining parts of a loudspeaker cabinet.
One method of joining wood parts comprises a moisture-expansive
wood wedge glued inside a straight-sided mortise. A disadvantage is
that the joint must remain immobile while the glue dries,
preventing immediate use of the joint, thereby appreciably
increasing the time and cost of assembly.
It is an important object of this invention to provide an improved
joint.
It is another object of the invention to achieve the preceding
object with a joint with substantially permanent holding power.
It is another object of the invention to achieve one or more of the
preceding objects independently of glue.
It is a further object of the invention to achieve one or more of
the preceding objects with a wide variety of materials.
It is still a further object of the invention to achieve one or
more of the preceding objects rapidly and economically.
SUMMARY OF THE INVENTION
According to the invention, one piece of solid material has a
grooved projection. A second piece of solid material has a
dovetail-shaped slot of outer width corresponding substantially to
the width of the projection on the first piece. A barbed wedge of
hard material, preferably metal or plastic, resides within the slot
with the wedge base on the slot base, the wedge top facing the
opening and points on the wedge sides facing the slot sides.
Preferably the wedge is formed with a slot of generally triangular
cross section facing the slot base. According to the invention, the
grooved projection of the first piece is forced into the slot of
the second piece to urge the wedge into the groove of the projetion
so that the wedge spreads the groove open until the sides of the
projection engage the walls of the dovetail-shaped slot while the
wedge point becomes embedded in the groove of the projection,
preventing the groove from closing and locking the projection into
the slot to establish a mechanically secure permanent joint without
glue. If desired, glue or other material may be first introduced
into the slot to form a substantially fluid-tight joint.
Numerous other features, objects and advantages of the invention
will become apparent from the following specification when read in
connection with the accompanying drawing in which:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional view of the components of the joint before
joining according to the invention;
FIG. 2 is a sectional view of the completed joint according to the
invention; and
FIG. 3 is a perspective contracted view of an exemplary wedge
according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference now to the drawing and more particularly FIG. 1
thereof, there is shown a sectional view of the components of the
joint according to the invention. A piece 11 of solid material,
which may be wood, plastic or other suitable material, has a
grooved projection or tongue 12. A second piece 13 of solid
material, which may be wood, plastic, metal or other suitable
material, has an angled slot or mortise 14 of trapezoidal cross
section with outer width slightly greater than the width of
projection 12 and less then the width of the base of slot 14. A
barbed wedge 15 formed with a triangular groove 21 facing the base
of slot 14 rests on this base with its top facing slot 16 of
projection 12 and its barbed sides facing the sides of slot 14. The
width of wedge 15 at the top and across the barbs is respectively
less and greater than the width of groove 16.
Referring to FIG. 2, there is shown a sectional view of the
completed joint. Urging pieces 11 and 13 together forces projection
12 into slot 14 and wedge 15 into groove 16 of projection 12. As
pieces 11 and 13 move together, wedge 15 expands groove 16, causing
the sides of projection 12 to engage the walls of slot 14.
Coincidently barbs, points or tynes 17 of wedge 15 embed themselves
in the walls of projection 12 inside groove 16, keeping groove 16
expanded and locking projection 12 into slot 14. .Iadd.Wedge 15 is
formed with means defining a flat surface 15' that engages the base
of slot 14. .Iaddend.
Referring to FIG. 3, there is shown a contracted perspective view
of wedge 15. Slit 21 of triangular cross section helps insure that
wedge 15 may expand to spread projection 12 into engagement with
the walls beside slot 14 while narrowing to relieve pressure as
projection 12 encounters resistance from the walls beside slot 14.
This arrangement helps prevent fracture of pieces 11 and 13. Wedge
15 is preferably shaped so that the angle between the walls beside
slot 21 are two degrees to five degrees wider than the angle
between the walls beside slot 14 to insure that barbs 17 bite into
the sides of groove 16 in projection 12. The latter angle is
typically 14.degree.. The height of triangular slot 21 is typically
70% of the height of wedge 15. Wedge 15 may be of any length.
If desired, a bonding or sealing agent may also be used in groove
16 and/or slot 14, such as glue, to establish a substantially
fluid-tight seal and/or increase the strength of the joint. Wedge
15 may be made of metal, plastic or other suitable material,
preferably at least as hard as the material of pieces 11 and 13 so
that barbs 17 will deform the walls beside groove 16. Wedge 15 may
extend for substantially all or a fraction of the length of
projections 12 and slot 14. Alternatively, a number of wedges 15
may be spaced along the length of the joint.
A feature of the invention is that it provides a stable permanent
joint that may be handled immediately and requires no holding
fixtures. The result is more rapid and economical assembly. The
invention may be used to join a wide variety of materials at a wide
variety of angles.
In a specific embodiment of the invention joining wooden pieces of
a loudspeaker cabinet, typically 3/4-inch baraboard that may be
veneered, projection 12 is typically 0.37 inches wide, groove 16 is
typically 0.125 inches wide, the height of projection 12 is
typically 11/32 inch, the height of groove 16 is typically 8/32
inch, the depth of groove 14 is typically 0.39 inches and its top
and bottom widths are typically 0.38 inches and 0.50 inches,
respectively. The width of barb 15 at its base is typically 0.17
inches and across the barbs 17 is typically 0.23 inches.
There has been described novel apparatus and techniques for joining
two pieces of solid material economically and rapidly in a joint
characterized by substantial stability and permanence. Numerous
other departures from and modifications of the specific embodiments
described herein may now be practiced by those skilled in the art
without departing from the inventive concepts. Consequently, the
invention is to be construed as embracing each and every novel
feature and novel combination of features present in or possessed
by the apparatus and techniques herein disclosed and limited solely
by the spirit and scope of the appended claims.
* * * * *