U.S. patent application number 13/418632 was filed with the patent office on 2013-09-19 for invisible butt joint fastener.
This patent application is currently assigned to Jian Wang. The applicant listed for this patent is Jian Wang. Invention is credited to Jian Wang.
Application Number | 20130239509 13/418632 |
Document ID | / |
Family ID | 49156369 |
Filed Date | 2013-09-19 |
United States Patent
Application |
20130239509 |
Kind Code |
A1 |
Wang; Jian |
September 19, 2013 |
INVISIBLE BUTT JOINT FASTENER
Abstract
A fastener for connecting two structural pieces over abutting
surfaces with no or minimum exposure of the fastener itself. Each
fastener comprises a male and a female member to be fixed into
abutting surfaces of the structural pieces to be connected. The
tongue of the male member can be inserted into and slide inside the
socket of the female member when the two structural pieces slide
against each other along the abutting surface. The socket surface
is partially covered with raised ribs, that can catch the ribs on
the male tongue when the tongue is at the locking position but not
at the releasing position. All the ribs are slopped relative to the
sliding direction to convert part of the sliding action into a
pulling action, so as to create a preload between the structural
pieces when connected.
Inventors: |
Wang; Jian; (Sunnyvale,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wang; Jian |
Sunnyvale |
CA |
US |
|
|
Assignee: |
Wang; Jian
Sunnyvale
CA
|
Family ID: |
49156369 |
Appl. No.: |
13/418632 |
Filed: |
March 13, 2012 |
Current U.S.
Class: |
52/704 |
Current CPC
Class: |
A47B 2230/0081 20130101;
F16B 12/125 20130101 |
Class at
Publication: |
52/704 |
International
Class: |
E04B 1/38 20060101
E04B001/38 |
Claims
1. A fastener for joining structural pieces over abutting surfaces,
comprising a) a male member, which further comprising a tongue for
extending from a mating surface of a first structural piece to be
connected, and a plurality of outward-facing ribs on surface of
said tongue running generally alongside said mating surface of said
first structural pieces, and, b) a female member, which further
comprising a generally slotted socket for receding from a mating
surface of a second structural piece to be connected, and said
socket further comprising a ribbed section covered with a plurality
of inward-facing ribs running generally alongside said mating
surface of said second structural piece for engaging said
outward-facing ribs on said tongue, and a flat section for allowing
said tongue to be inserted into or extracted from freely,
therefore, said tongue may be locked inside said socket in a
locking action, which is sliding from said flat section to said
ribbed section of said socket, and unlocked in a releasing action,
which is sliding from said ribbed section to said flat section of
said socket.
2. The fastener of claim 1, wherein, a) said outward-facing ribs of
said tongue comprising a rail edge, which faces and inclines
towards said mating surface of said first structural piece at a
small lead angle along said opening action direction, and b) said
inward-facing ribs of said socket comprising a rail edge, which
faces against and inclines towards said mating surface of said
second structural piece at said small lead angle along said opening
action direction, therefore, said rail edge of outward-facing ribs
of said tongue can glide against said rail edge of inward-facing
ribs of said socket to pull said male member and said female member
closer in said locking action.
3. The fastener of claim 1, wherein said male member comprising an
elastic retaining clip, normally extending from but can be
depressed into said mating surface of said first structural piece,
and is located relative to said tongue so that when said tongue is
fully locked into said ribbed section of said socket, said
retaining clip springs right into said flat section of said socket
to restrict said opening action.
Description
BACKGROUND
[0001] Butt joint is one of the simplest wood joints both in terms
of construction and appearance. Many modern furniture used
mechanical fasteners, such as the cam-dowel described in German
Auslegeschrift 2625182 and U.S. Pat. No. 4,131,376, to recreate the
simple look; however, each fastener has to expose certain
tightening/releasing interface, and hiding the interface inside a
furniture may not aways be feasible. These fasteners also typically
require two interconnected holes, which are harder than single hole
to drill.
[0002] The present invention is a butt joint fastener, designed
with the objectives to eliminate or minimize its visibility, and
simplify the making and assembling of furniture. The new fastener
is primarily designed to be used in groups to connect structural
pieces so that they can all be locked in one sliding action between
the two pieces along the abutting surfaces, rather than being
tightened individually like traditional fasteners, thus no exposure
to the fastener is needed as the tightening and releasing forces
are directly applied to the structural pieces instead of the
fasteners. The fastener requires only one groove on the abutting
surface of the structural piece, and can be routed out relatively
easily.
SUMMARY
[0003] A fastener for connecting two structural pieces over
abutting surfaces is presented. Each fastener comprises a male and
a female member. A series of such fasteners are typically fixed
into the abutting surfaces of the structural pieces to be
connected, with the two members on opposite structural pieces and
leaving only the tongues of the male members sticking out of the
abutting surfaces. The male tongue can slide inside the female
socket when the two structural pieces slide against each other
along the abutting surface, and the socket surface is partially
covered with raised ribs, that can catch the ribs on the male
tongue when the tongue is at the locking position but not at the
releasing position. All the ribs are slopped relative to the
sliding direction to convert part of the sliding action into a
pulling action, so as to create a preload between the structural
pieces when connected. The lead angle between the ribs and the
abutting surface is small, so friction can keep the fastener from
sliding open even when a pulling force perpendicular to the
abutting surface is applied, but an optional elastic retaining clip
may further prevent the joint from accidental sliding open.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a perspective partial section view of the
preferred embodiment of the fastener.
[0005] FIG. 2 is a parallel side view of the preferred embodiment
of the fastener.
[0006] FIG. 3 is a typical application of the fastener, where a
series of the fastener are used to butt join two structural
pieces.
[0007] FIG. 4 is a lockable embodiment of the fastener.
[0008] FIG. 5 is the typical application of the lockable
embodiment.
[0009] FIG. 6 is a perspective view of a curved embodiment of the
current invention.
DETAILED DESCRIPTION OF THE DRAWINGS
The Preferred Embodiment--FIGS. 1 Through 3
[0010] FIG. 1 is a perspective view of the preferred embodiment of
the current invention, with the female member drawn in section. The
male member has a generally elongated body 10 with a head end 11, a
tail end 12, a fore-face 13, a tongue 14 extending from the
fore-face 13, and a series of raised ribs 15 on the surface of the
tongue 14. The female member has an elongated body 20 with a head
end 21, a tail end 22, a fore-face 23, a socket 24 indenting into
the fore-face 23, and a series of raised ribs 25 on part of the
inner surface of the socket 24 near the head end 21.
[0011] FIG. 2 shows the same preferred embodiment in parallel
projection from a side. The male tongue 14 can be inserted into the
rib-free region of the socket 24 near the tail end 22, and slide
towards the head end 21 to get locked inside. The unlocking process
is just opposite the locking process, and both processes are shown
with the arrow-ended line in the FIG. 2. The male ribs 15 runs with
a small lead angle between the rail edge 150 and the fore-face 13,
inclining towards the fore-face 13 near the tail end 12. The rail
edge 250 of the female rib 25 also runs with a lead angle matching
that of the rail edge 150. The two rail edges 150 and 250 can glide
against each other to pull the two members closer together in the
locking action. The male member fore-face 13 has a small hump near
the tail end 12 to form a retaining clip 130 that may clip to the
inside wall of the female socket 24. Due to the natural elasticity
of the material, the retaining clip 130 does totally prevent the
tongue 14 from sliding out of the socket 24, but does make
accidental releasing much harder.
[0012] The FIG. 3 shows the typical application of the fastener in
connecting two structural pieces 30. The bodies 10 and 20 are
pre-glued into grooves, leaving only the male tongues 14 extending
out of the abutting surface. All fasteners are lined up in a row so
all male tongues 14 can be inserted into female sockets 24
simultaneously, and be locked with one sliding action between the
two structural pieces 30.
Alternatives--FIGS. 4 Through 6
[0013] The lead angle between the ribs 15/25, or more specifically
the rails 150/250, and their respective fore-faces 13/23 is small,
so friction can keep the fastener from sliding open even when a
pulling force perpendicular to the abutting surface is applied to
the locked fastener; therefore, the retaining clip 130 can be
eliminated in applications where no side-way forces are expected on
a joint.
[0014] On the other hands, when side-way motion is frequent or
severe, a more secure lock such as the latch 16 in FIG. 4 may be
needed. The latch 16 is designed to be higher than the retaining
clip 130 above the fore-face 13, so the latch 16 cannot be opened
by side-way forces alone when locked inside the female socket 24.
The only way to unlock the latch is to push it directly down
towards the body 10. A gap 161 between the bottom of the latch 16
and the male body 10 allows the latch to bend down, and a narrow
waist 160 makes the bending easier. The sides of the latch are
beveled 162 to allow easier tool access to the top of the latch
160. As shown in the FIG. 5, a screw driver 40 is inserted from the
side of the latch, through a channel 31 in the structural piece 30,
to push the latch 16 down when unlocking is needed. Although the
fastener is not totally invisible in this case, the exposure is
still minimal comparing to traditional fasteners.
[0015] Butt joints are used not only for connecting straight edges
of structural pieces. FIG. 6 showed a curved embodiment of the
current invention that can be used to connect curved edges, which
are often seen in trade-show display construction. A moderate
degree of flexibility can also be achieved with certain plastic
materials without making the fastener overly stretchy.
[0016] The FIG. 6 also showcased several minor variations to the
preferred embodiment. The ribs 15 on both sides of the male tongue
14 are connected at the head end 11. In fact, they can be connected
at the tail end 12 too, or broken somewhere as long as gliding on
female rib 25 is not interfered, or even leaving one entire side of
the tongue flat. The same is true for female ribs 25 as well. Many
of the detailed features of the ribs 15/25 shown in the FIG. 1
through FIG. 5, such as the rounded endings and the chamfered
non-rail edges, are more for a smooth looking than for any
function, can be eliminated as shown in the FIG. 6.
[0017] The male body 10 and female body 20 may be glued into
structural pieces 30 as shown in the FIG. 3; however, other means
of fastening are equally valid with straightforwards modifications
to them. For example, the female body 20 may include holes at the
bottom to be screwed into grooves, or the male body 10 may be made
thinner with screw holes on it.
* * * * *