U.S. patent number 3,574,367 [Application Number 04/759,386] was granted by the patent office on 1971-04-13 for coupling.
Invention is credited to Johannes Jankowski.
United States Patent |
3,574,367 |
Jankowski |
April 13, 1971 |
COUPLING
Abstract
A coupling which comprises two clamping members insertable into
the open-ended chamber of a first element and two locking members
located between the clamping members and having hooks extending
through an aperture provided in a wall of a second element. A bolt
can move the locking members apart to thereby urge the clamping
members against the first element and to engage the hooks with that
side of the wall which faces away from the chamber. The clamping
members and the locking members are provided with cams and
followers or analogous tensioning devices which cooperate to urge
the hooks toward the clamping members when the locking members move
apart whereby the wall is pressed against the clamping members
and/or against the first element.
Inventors: |
Jankowski; Johannes (N/A,
IT) |
Family
ID: |
5684903 |
Appl.
No.: |
04/759,386 |
Filed: |
September 12, 1968 |
Foreign Application Priority Data
|
|
|
|
|
Jan 26, 1968 [DT] |
|
|
J35593X11/47a |
|
Current U.S.
Class: |
403/201;
403/DIG.10; 403/297; 403/343; 403/409.1; 403/322.1 |
Current CPC
Class: |
F16B
7/0473 (20130101); B62D 33/044 (20130101); E04F
11/1817 (20130101); E06B 3/98 (20130101); E06B
3/972 (20130101); E04B 2/76 (20130101); Y10S
403/10 (20130101); Y10T 403/76 (20150115); Y10T
403/591 (20150115); Y10T 403/557 (20150115); Y10T
403/68 (20150115); F16B 2200/205 (20180801) |
Current International
Class: |
B62D
33/00 (20060101); B62D 33/04 (20060101); E06B
3/972 (20060101); E04F 11/18 (20060101); F16B
7/04 (20060101); E04B 2/76 (20060101); E06B
3/96 (20060101); E06B 3/98 (20060101); F16b
007/04 () |
Field of
Search: |
;287/189.36 (C)/ ;287/54
(A)/ ;287/54 (B)/ ;287/54 (C)/ ;287/2,124,56 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
96,260 |
|
Jun 1960 |
|
NO |
|
403,207 |
|
Jun 1966 |
|
CH |
|
Primary Examiner: Callaghan; Thomas F.
Assistant Examiner: Kundrat; Andrew V.
Claims
I claim:
1. A coupling for establishing a connection between a structural
element which is provided with an open-ended chamber and an
apertured wall adapted to be placed adjacent to the open end of the
chamber so that one of its sides faces away from the element,
comprising a clamping unit having two clamping members in the
chamber of the structural element; a locking unit comprising a pair
of locking members disposed between said clamping members and
movable between first and second positions in which they are
respectively located at a first and a second distance from each
other, said locking members having front portions insertable
through the apertured wall in the first positions and overlying the
one side of the wall in the second positions thereof; actuating
means for moving the locking members between said positions; and
tensioning means provided on said members to urge said front
portions toward said clamping members in response to movement of
locking members toward said second positions.
2. A coupling as defined in claim 1, wherein said tensioning means
comprises cams provided on the members of one of said units and
followers provided on the members of the other unit and each
engaging with one of said cams during at least a portion of
movement of said locking members toward second positions.
3. A coupling as defined in claim 1, wherein said tensioning means
are at least slightly spaced from said front portions.
4. A coupling as defined in claim 1, wherein at least one member of
at least one of said units is deformable and undergoes deformation
in response to movement of locking members toward said second
positions.
5. A coupling as defined in claim 4, wherein said deformable member
is one of said clamping members.
6. A coupling as defined in claim 1, wherein said tensioning means
comprises abutments pairs of abutments provided on each of said
clamping members and the adjoining locking members.
7. A coupling as defined in claim 2, wherein said tensioning means
comprises sloping cam faces.
8. A coupling as defined in claim 1, wherein the members of one of
said units are of arcuate shape in the first positions of said
locking members and consist of deformable material so that they can
undergo deformation and flatten out in response to movement of
locking members toward said second positions.
9. A coupling as defined in claim 1, further comprising fastener
means connecting said clamping members to each other so that both
said clamping members can be inserted into the structural element
as a unit.
10. A coupling as defined in claim 1, further comprising means for
connecting said locking members to each other, at least in the
first positions thereof, so that the thus connected locking members
can move as a unit with reference to the structural element.
11. A coupling as defined in claim 1, wherein the members of at
least one of said units are integral with each other.
12. A coupling as defined in claim 1, further comprising means for
biasing at least one of said locking members to first position.
13. A coupling as defined in claim 12, wherein said biasing means
comprises resilient elements each interposed between one of said
locking members and one of said clamping members.
14. A coupling as defined in claim 1, wherein said tensioning means
comprises first groups of teeth provided on said clamping members
and second groups of teeth provided on said locking members, each
second group of teeth engaging one first group of teeth at least
during a portion of movement of said locking members to second
positions.
15. A coupling as defined in claim 14, wherein said tensioning
means further comprises cooperating cams and followers provided on
said locking members and the adjoining clamping members, said
followers being disengaged from the respective cams in response to
engagement between said first and second groups of teeth.
16. A coupling as defined in claim 1, wherein said clamping members
are provided with unevennesses which bear against the structural
element at least in response to movement of locking members to said
second positions.
17. A coupling as defined in claim 1, wherein at least one of said
clamping members is fixed to the structural element.
18. A coupling as defined in claim 1, wherein at least one of said
clamping members is integral with the structural element.
19. A coupling as defined in claim 1, wherein said clamping members
comprise front portions which bear against the apertured wall in
the second positions of said locking members.
20. A coupling as defined in claim 19, wherein the front portions
of said clamping members are flush with the open end of the chamber
in the structural element in the second positions of said locking
members.
21. A coupling as defined in claim 19, wherein the front portions
of said clamping members extend beyond the open end of the chamber
in the structural element in the second positions of said locking
members.
22. A coupling as defined in claim 1, wherein said actuating means
comprises an actuating member which is accessible, through an
opening in the structural element.
23. A coupling as defined in claim 1, wherein said actuating means
comprises an externally threaded actuating member which meshes with
one of said locking members and is rotatable to thereby move the
other clamping member away from said one clamping member.
24. A coupling as defined in claim 1, wherein said actuating means
comprises an explosive charge which can be set off by heating to
thereby move the locking members to said second positions.
25. A coupling as defined in claim 1, wherein said front portions
are arranged to extend through a rounded aperture of the wall in
first positions of said locking members.
26. A coupling as defined in claim 1, wherein the clamping members
have convex outer faces so that they can be fitted into a chamber
of substantially circular outline.
27. A coupling as defined in claim 1, wherein said clamping members
have concave front face adapted to engage a convex second side of
the wall in the second positions of said locking members.
28. A coupling as defined in claim 1, wherein the apertured wall
forms part of an intermediate element by means of which the
structural element is connectable with at least one second
structural element.
29. A coupling as defined in claim 28, wherein the intermediate
element is a body of circular or polygonal outline.
Description
BACKGROUND OF THE INVENTION
The present invention relates to couplings in general, and more
particularly to improvements in couplings which can establish
separable or permanent connections between identically or
differently dimensioned and/or configurated structural elements.
Still more particularly, the invention relates to couplings which
can be utilized to establish connections between rods, bars, tubes,
pipes, cylinders, sleeves, hollow or solid profiled stock, flat
bodies and/or other types of elements which can form component
parts of furniture, scaffolds, room dividers, shelves, racks,
frames and/or many others,
It is already known to employ in the manufacture of furniture
couplings of the type which are installed in one element and
comprise movable locking members adapted to engage another element
and to thus establish a connection between the two elements. A
drawback of such couplings is that the connections are unstable,
i.e., the two interconnected elements are normally free to pivot,
wobble or to otherwise move relative to each other. This is
undesirable when a coupling is used to connect parts of chairs,
beds, sofas, tables or other pieces of furniture. Moreover, all
components or many components of conventional couplings must be
machined or otherwise finished with a high degree of precision, and
the same applies for the dimensioning and finish of elements which
are connected to each other by such couplings. This is especially
necessary when a conventional coupling is employed in assembling
parts of frames cannot mirrors, panels or the like. Also, presently
known couplings cannot compensate for deviations in dimensions of
structural elements from a given norm.
Certain other types of conventional couplings employ eccentrics,
screws or bolts which must be driven into or moved firmly against
the structural elements to thereby insure the establishment of
rigid and reliable connections between two or more elements. A
drawback of such couplings is that, in order to properly hold a
screw or bolt or to resist the pressure of an eccentric, the walls
of the structural elements must have a certain minimum thickness
and a certain minimum rigidity which automatically eliminates such
couplings from use in connection with a wide variety of parts.
Moreover, the holes or bores for the screws or bolts must be
drilled and tapped at predetermined locations which contributes to
the manufacturing cost and necessitates the use of precision tools.
It is often difficult or impossible to drill holes at the locale of
use, especially if the elements which are to be joined by a
coupling cannot be cut to size at the manufacturing plant. Proper
determination of the location of holes, recesses or the like at the
place of assembly necessitates the use of complicated equipment and
must be carried out by skilled labor in a time-consuming
operation.
SUMMARY OF THE INVENTION
It is an object of my invention to provide a novel and improved
coupling which can be used to establish rigid connections between
prefabricated parts, which can be installed and/or taken apart in a
manufacturing plant or workshop as well as at the locale of use by
resorting to simple and readily available tools, and which can be
used for connection of rugged, bulky and thick-walled as well as of
lightweight and thin-walled structural elements.
Another object of the invention is to provide a coupling which is
designed in such a way that the force with which two or more
elements are connected to each other can be changed at the will of
the operator and which can compensate for at least some
inaccuracies in the machining and/or dimensioning of elements which
are being connected to each other.
A further object of the invention is to provide a coupling which
can be installed or disengaged by exertion of a small force.
An additional object of the invention is to provide a coupling
which may but need not utilize threaded parts and wherein such
threaded parts need not engage with the elements which must be
connected to each other.
Still another object of the invention is to provide a coupling
which can be installed by persons having little experience or
skill, which can establish a connection that cannot be readily
terminated or weakened in normal use, and which is at least nearly
completely concealed when properly installed to furnish a
connection between two or more structural elements.
A concomitant object of the invention is to provide a coupling
whose components are automatically moved into firm and reliable
engagement with each of the two structural elements when the
coupling is properly installed and applied to join the elements to
each other.
An ancillary object of the invention is to provide a coupling which
can be installed or removed within short periods of time.
Briefly stated, the improved coupling is utilized to establish a
temporary or permanent connection between a structural element
which is provided with an open-ended chamber and an apertured wall
adapted to be placed adjacent to the open end of the chamber so
that one of its sides then faces away from the structural element.
The coupling comprises a clamping unit having two clamping members
in the chamber of the structural element (such clamping members may
be inserted into or they may form temporarily or permanently fixed
or integral parts of the structural element), a locking unit
comprising a pair of locking members disposed between the clamping
members and movable between first and second positions in which
they are respectively located at a first and at a second distance
from each other, the locking members having preferably hook-shaped
or claw-shaped front portions insertable through the apertured wall
in the first positions and overlying the one side of such wall in
the second positions of locking members, actuating means for moving
the locking members between the first and second positions, and
tensioning means provided on the members to urge the front portions
toward the clamping members in response to movement of locking
members toward second positions.
The tensioning means may comprise cooperating integral portions of
the locking and clamping members, and such portions are preferably
remote from the front portions of locking members. For example, the
tensioning means may comprise cams provided on the clamping members
and followers provided at the rear ends of locking members and
engaging the respective cams, at least during a portion of movement
of locking members from first to second positions. Such cams and
followers insure that the wall is urged toward the structural
element on movement of locking members toward second positions and
bears against the front ends of clamping members and/or against the
structural element to thus prevent wobbling, pivoting or other
undesirable movements of the wall with reference to the structural
element or vice versa.
The novel features which are considered as characteristic of the
invention are set forth in particular in the appended claims. The
improved coupling itself, however, both as to its construction and
its mode of operation, together with additional features and
advantages thereof, will be best understood upon perusal of the
following detailed description of certain specific embodiments with
reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a central longitudinal sectional view of a coupling which
embodies one form of my invention and whose parts are shown in a
starting position prior to establishment of a rigid but separable
connection between two hollow structural elements;
FIG. 2 is a similar central longitudinal sectional view of a second
coupling whose parts are also shown in a starting position;
FIG. 3 is a central longitudinal sectional view of two different
couplings which are employed to connect two structural elements to
a common intermediate element, a portion of a third coupling which
connects the intermediate element with a third structural element
being shown in front elevational view;
FIG. 4 is a central longitudinal sectional view of a fourth
coupling;
FIG. 5 is a central longitudinal sectional view of a fifth
coupling;
FIG. 6 is a central longitudinal sectional view of a sixth
coupling;
FIG. 7 is a central longitudinal sectional view of a seventh
coupling;
FIG. 8a is a central longitudinal sectional view of a further
coupling wherein the parts are shown in positions they assume prior
to establishment of a rigid connection between two hollow
structural elements;
FIG. 8b is a similar sectional view but showing the parts of the
coupling in intermediate positions;
FIG. 8c is a similar view but showing the parts of the coupling in
their final or operative positions;
FIG. 9a is a perspective view of a first locking member in the
coupling of FIGS. 8a--8c; and
FIG. 9b is a similar perspective view of a second locking member in
the coupling of FIGS. 8a--8c.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown a coupling which is
employed to establish a rigid but readily separable connection
between a first structural element 1 and a wall 10 which forms part
of a second structural element 11. The element 1 is hollow and is
provided with an internal chamber 2 at least one end of which is
open and which accommodates the two main units 3, 4 of the
coupling. The unit 3 is a clamping or retaining unit and comprises
two clamping members 12, 13. The other unit 4 is a locking or
connecting unit and comprises two locking members 5, 6. The front
portions of the locking members 5, 6 form two hooks or claws 7, 8
which extend through an opening or aperture 10a in the front end
wall 10 of the structural element 11 and into an internal
compartment or chamber 10b of this element. A spreading or
actuating member, here shown as a screw or bolt 9, is employed to
move the locking members 5, 6 apart and to thereby cause the hooks
7, 8 to engage the inner side of the end wall 10, i.e., that side
of the wall 10 which faces away from the open end of the chamber 2.
The bolt 9 also causes (indirectly) the locking members 6 to move
in a direction to the left, as viewed in FIG. 1 and to thereby form
a rigid link between the clamping members 12, 13 and the end wall
in order to prevent movements of the element 1 with reference to
the element 11 or vice versa. The elements 1, 11 may constitute two
hollow profiled rods or bars which form part of a piece of
furniture, for example, two portions of a chair or table. The
improved coupling serves to connect the elements 1, 11 to each
other in such a way that the end wall 10 is at least substantially
normal to the longitudinal direction of the element 1.
The clamping members 12, 13 are of identical size and shape and are
loosely connected to each other by a rivet 14 or an analogous
fastener. These clamping members respectively comprise straight
portions or legs 15, 16 whose rear or inner (left-hand) end
portions are suitably bent to be located rather close to each other
and to accommodate the shank of the fastener 14. The legs 15, 16
are provided with U-shaped slits and the portions within the
confines of such slits are bent to form two inwardly extending
substantially V-shaped tensioning cams or abutments 17, 18 which
are mirror symmetrical with reference to the central longitudinal
symmetry plane of the coupling. The faces of the cams 17, 18 are
respectively shown at 19 and 20; these cam faces slope inwardly and
forwardly, i.e., toward the structural element 11 and can be
engaged by abutment or followers 25, 26 adjacent to the rearmost or
innermost portions of the locking members 5, 6. The bights of the
cams 17, 18 respectively extend into cutouts or windows 23, 24
provided in the locking members 5, 6 in front of the followers 25,
26.
The outer sides of the legs 15, 16 are provided with ribs,
serrations, teeth or analogous unevennesses 22 which can penetrate
into the adjoining surfaces in the chamber 2 of the structural
element 1 to thus prevent lengthwise displacement of the clamping
unit 3. Two leaf springs 27, 28 are respectively inserted between
the members 5, 12 and 6, 13 to bias the serrations 22 against the
adjoining surfaces of the structural element 1 and to
simultaneously urge the locking members 5, 6 toward each other,
namely, to first positions in which the locking members are
disposed substantially centrally between the legs 15, 16 of the
clamping members 12, 13.
A sidewall or panel of the element 1 is formed with an opening or
aperture 29 which affords access to the slotted head of the
actuating bolt 9 so that the latter can be engaged by a suitable
tool. The spaces between the aforementioned U-shaped slits of the
legs 15, 16 provide additional openings or apertures 30, 31 the
former of which registers with the opening 29 and enables an
operator to place the stem of the bolt 9 into mesh with the
clamping member 5 which latter is formed with a tapped hole 32. The
length of the openings 29, 30 is selected in such a way that the
hooks 7, 8 of the locking members 5, 6 can be introduced into the
compartment 10b while at the same time enabling the operator to
move the hooks 7, 8 into the chamber 2 so that the entire coupling
is then accommodated in the element 1. The locking member 5 has a
bent over rear end portion of tip 21 which can engage the rear end
face of the locking member 6 to move the latter toward the element
11 when the operator engages the bolt 9 and pushes the hook 7 of
the locking member 5 through the opening 10a and into the
compartment 10b. An internal partition 33 of the element 11 limits
the extent to which the hooks 7, 8 can penetrate into the element
11.
The operation is as follows:
In the first step, the main units 3, 4 of the coupling are inserted
into the element 1 so that the hooks 7, 8 are accommodated in the
chamber 2. The leaf springs 27, 28 bias the locking members 5, 6 to
the illustrated first positions. Introduction of the coupling into
the chamber 2 can be effected by resorting to a tool which engages
the head of the actuating bolt 9 and is caused to push the locking
member 5 in a direction to the left, as viewed in FIG. 1. The
locking member 5 engages the cam 17 of the clamping member 12 and
the latter shifts the clamping member 13 by way of the fastener 14.
The spring 28 entrains the locking member 6. The element 11 is then
placed against or close to the end face of the element 1 and the
tool which engages the actuating bolt 9 is caused to push the
locking members 5, 6 to the positions shown in FIG. 1, i.e., the
hooks 7, 8 are fully accommodated in the compartment 10b. The tip
21 of the locking member 5 engages and pushes the locking member 6
when the bolt 9 is caused to move in a direction to the right.
During such shifting, the inner end of the bolt 9 need not engage
the locking member 6, i.e., it suffices if the bolt extends into
but not beyond the tapped hole 32 of the locking member 5. The
hooks 7, 8 are then adjacent to the outer side of the partition 33
in the element 11.
In the next step, the operator rotates the bolt 9 in a sense to
move the locking members 5, 6 apart and to thus deform the leaf
springs 27, 28. This moves the hooks 7, 8 away from each other and
into registry with the inner side of the end wall 10. As the
operator continues to rotate the bolt 9, the followers 25, 26 slide
along the faces 19, 20 of the cams 17, 18 and cause the locking
members 5, 6 to move in a direction to the left so that the hooks
7, 8 engage the inner side of the wall 10. Such engagement between
the hooks 7, 8 and wall 10 takes place after the followers 25, 26
move the clamping members 12, 13 in a direction to the right and
into abutment with the outer side of the end wall 10. As the bolt 9
continues to move the locking members 5, 6 away from each other,
the followers 25, 26 cause the serrations 22 to penetrate into the
element 1 and to thus prevent any lengthwise displacement of the
clamping members 12, 13. The inclination of faces 19, 20 on the
cams 17, 18 is such that the followers 25, 26 can spread the hooks
7, 8 into registry with the inner side of the end wall 10, that the
clamping members 12, 13 are caused to abut against the outer side
of the end wall 10, that the hooks 7, 8 engage the inner side of
the end wall 10, and that the serrations 22 penetrate into the
element 1. This completes the installation of the coupling which
then provides a rigid but readily separable connection between the
elements 1 and 11.
In order to release or disengage the coupling, the operator simply
turns the bolt 9 in a sense to permit the springs 27, 28 to return
the locking members 5, 6 to the first positions shown in FIG. 1.
The hooks 7, 8 then register with the opening 10a and can be
withdrawn from the compartment 10b. In the coupling of FIG. 1, the
cams 17, 18 and followers 25, 26 constitute a tensioning device
which serves to urge the hooks 7, 8 toward the clamping members 12,
13 in response to rotation of the actuating bolt 9 in a sense to
move the locking members 5, 6 away from first positions. This
tensioning device is remote from the hooks 7, 8.
The units 3, 4 may consist of metallic or plastic material.
FIG. 2 illustrates a second coupling which provides a separable
connection between two hollow structural elements 34 and 35. These
elements are of rectangular outline and are joined end to end. The
element 35 has an end wall 35a provided with an opening or aperture
35b communicating with an internal chamber or compartment 35c. The
adjoining end of the chamber 34a in the element 34 is open and one
of the sidewalls 54 of the element 34 is provided with an elongated
opening or aperture 56.
The coupling of FIG. 2 comprises a clamping unit 36 and a locking
unit 37. The clamping unit comprises two clamping members 39, 40
and the locking unit 37 comprises two locking members 46, 47. The
front portions of the locking members 46, 47 form hooks 46a, 47a
similar to the hooks 7, 8 shown in FIG. 1. The rear portions of the
clamping members 39, 40 are loosely connected to each other by a
fastener 38. The numerals 40a, 41 denote the U-shaped front end
portions or tensioning cams of the clamping members 39, 40 and
these tensioning cams 40a, 41 are respectively provided with
flanges 42, 43 which are substantially normal to the longitudinal
direction of the element 34. Furthermore, the cams 40a, 41 have
sloping or inclined faces 44, 45 which correspond to the cam faces
19, 20 shown in FIG. 1.
The locking members 46, 47 have followers 48, 49 which can
cooperate with the faces 44, 45 of tensioning cams 40a, 41. The
inner or rear end portions 50, 51 of the locking members 46, 47 are
bent outwardly and away from each other to form retainers for a
pair of resilient elements here shown as helical expansion springs
52, 53 operating between the clamping members 39, 40 and the median
portions of locking members 46, 47. The springs 52, 53 tend to bias
the locking members 46, 47 toward each other to thereby maintain
the hooks 46a, 47a at the front ends of these locking members in
registry with the opening 35b. At the same time, the springs 52, 53
bias the serrated or toothed external surfaces of clamping members
39, 40 against the internal surfaces of sidewalls 54 of the element
34.
The locking member 47 has a boss or enlargement which is provided
with a tapped hole to take the stem of an actuating bolt 55 whose
head is accessible through the aforementioned opening 56 and a
registering opening 57 in the clamping member 40.
The operation of the just described coupling is clearly analogous
to that of the coupling shown in FIG. 1. When the actuating bolt 55
is rotated in a sense to move the locking members 46, 47 apart
(from first to second positions), the followers 48, 49 cooperate
with the faces 44, 45 of tensioning cams 40a, 41 to draw the hooks
46a, 47a of the locking members into engagement with the inner side
of the end wall 35a, to move the flanges 42, 43 into abutment with
the outer side of the end wall 35a, and to force the serrations of
clamping members 39, 40 into the material of the adjoining
sidewalls 54. Thus, the clamping members 39, 40 are rigidly secured
to the element 34, the followers 48, 49 urge the flanges 42, 43
against the outer side of the end wall 35a, and the followers
simultaneously urge the hooks 46a, 47a of the locking members 46,
47 against the inner side of the end wall 35a to thus prevent any
movement of the elements 34, 35 with reference to each other. In
this embodiment of my invention, the tensioning device including
the cams 40a, 41 and followers 48, 49 is spaced from, but is not
very remote from the hooks 46a, 47a. At least one of the clamping
members 12, 13 and/or at least one of the locking members 5, 6 may
consist of an elastic material which is deformed in response to
movement of locking members from first to second positions.
FIG. 3 illustrates the manner in which two or more hollow profiled
structural elements can be connected to each other through the
intermediary of a cubelike or dicelike intermediate or connecting
element 62. The illustration shows two profiled structural elements
60, 61 which are connected to each other by way of the intermediate
element 62, and this illustration further shows a portion of a
coupling which connects the intermediate element 62 with a further
profiled structural element similar to the structural element 60 or
61.
The couplings which connect the structural elements 60, 61 to the
intermediate element 62 are of identical design and therefore, only
one of these coupling (namely, that between the elements 61 and 62)
will be described in full detail. The intermediate element 62 has
six walls each of which is formed with a round inlet opening or
aperture 81 adapted to receive the hooks or claws 79, 80 of one of
the couplings. Each coupling comprises two U-shaped clamping
members 63, 64 and two locking members 73, 74. The clamping members
63, 64 have suitably bent inner or rear end portions 65 which are
loosely connected to each other by a fastener 66. The flanges 67,
68 at the front ends of clamping members 63, 64 abut against the
outer side of the adjoining apertured wall of the intermediate
element 62 when the coupling is in operative position. The rear
flanges 69, 70 of the clamping members 63, 64 are adjacent to the
end portions 65 and constitute two tensioning cams provided with
slots 71, 72 for the followers 75, 76 of the locking members 73,
74, respectively. These followers respectively engage with the
camming edges 77, 78 of the tensioning cams 69, 70. The hooks 79,
80 respectively constitute the front portions of the locking
members 73, 74. Circular openings or apertures 81 in the walls of
the intermediate element 62 are preferred at this time because such
apertures can be readily machined by resorting to available tools
or machines. It will be seen that the hooks 79, 80 are bounded by
arcuate (convex surfaces) having radii of curvature similar to the
radii of apertures 81.
Helical springs 82, 83 are inserted between the clamping members
63, 64 and the adjoining locking members 73, 74 to bias the hooks
79, 80 toward each other and into registry with the respective
aperture 81. Openings or slots 85, 86 in a sidewall of the element
61 and in the clamping member 63 permit passage of the stem of an
actuating bolt 84 which meshes with the locking member 73 and can
move the latter away from the locking member 74 to thereby engage
the hooks 79, 80 with the inner side of the adjoining apertured
wall of the intermediate element 62 and to cause the followers 75,
76 to slide along the camming edges 77, 78 in order to force the
serrated outer sides of clamping members 63, 64 into the adjoining
internal surfaces of the structural element 61. The stem of the
actuating bolt 84 extends through the openings 85, 86 with at least
some clearance.
When the coupling is properly applied, the hooks 79, 80 engage the
inner side of the wall of the intermediate element 62, the flanges
67, 68 engage the outer side of such wall opposite the hooks 79,
80, the serrated portions of clamping members 63, 64 engage the
adjoining internal surfaces of the structural element 61, and the
springs 82, 83 store energy.
It will be noted that the coupling between the elements 61, 62 can
provide a rigid connection between such elements even though the
element 61 need not abut against the element 62. In other words,
the flanges 67, 68 of the clamping members 63, 64 can extend beyond
the open end of the element 61 to bear against the adjoining outer
side of the element 62. FIG. 3 further shows that the width of the
gap between the elements 60, 62 exceeds the width of the gap
between the elements 61, 62. The width of each such gap can be
determined in advance by properly selecting the initial axial
position of clamping members 63, 64 with reference to the
respective element 60 or 61. The openings 85 preferably resemble
elongated slots so that they permit lengthwise displacement of
actuating bolts 84 and of the remaining parts of corresponding
couplings. The surfaces flanking such openings or slots 85 need not
take up any stresses. The feature that the couplings of FIG. 3 can
be properly applied even if the element 60 or 61 does not abut
against the intermediate element 62 is of particular importance in
establishment of connections between elements which are not
machined with utmost precision. Thus, and particularly since the
width of the gap between the elements 60, 62 need not be the same
as that between the elements 61, 62, a shorter-than-average element
60 can be properly coupled to the element 62 together with an
element 61 of average length.
The heads of actuating bolts 84 need not extend beyond the elements
60, 61. As a matter of fact, and when such actuating bolts are
driven home to spread the locking members 73, 74 apart, their heads
may be located entirely within the confines of openings 86 in the
corresponding clamping members 63.
If the intermediate element is a hollow sphere or a hollow cylinder
(i.e., if its outline is circular rather than polygonal), the front
faces of flanges 67, 68 on the clamping members 63, 64 can be of
concave shape so that they can bear flush against a convex outer
side of a spherical or cylindrical intermediate element when the
actuating member 84 causes the locking members 73, 74 to the second
positions shown in FIG. 3.
The coupling of FIG. 4 is designed to provide an exceptionally
strong connection between two structural elements 87, 88, namely, a
connection whose strength approximates or even exceeds that of a
riveted joint. The difference between this coupling and the
previously described couplings is that the leaf springs or helical
springs are dispensed with and that the clamping members 89, 90 are
mounted in the open-ended chamber of the hollow element 87 in such
a way that they cannot be shifted toward or away from the element
88. As shown, the clamping members 89, 90 are respectively provided
with outwardly extending projections or protuberances 91, 92 which
are received in holes or recesses 93, 94 formed in adjoining walls
of the element 87. The front end faces 95 of the clamping members
89, 90 are flush with the end face of the element 87.
The locking members 96, 97 of the coupling shown in FIG. 4 are
U-shaped and respectively comprise front flanges or hooks 98, 99
and rear flanges 102, 103 each of which constitutes a follower. The
rear followers 102, 103 respectively cooperate with camming edges
104, 105 of the clamping members 90, 89, and the front followers or
hooks 98, 99 cooperate with camming edges 106, 107 flanking an
opening or aperture 108 in the end wall 88a of the element 88.
The locking member 97 has a tapped hole for an actuating bolt 109
which can be introduced through registering openings 110, 111
respectively provided in a sidewall of the element 87 and in the
clamping member 89. When the bolt 109 is rotated in a sense to move
the locking members 96, 97 apart, the hooks 98, 99 urge the end
wall 88a against the end faces 95 of clamping members 89, 90 and
the followers 102, 103 bear against the camming edges 104, 105 to
prevent withdrawal of projections 91, 92 from the respective
recesses 93, 94. In this embodiment of my invention, the tensioning
device comprises the followers 102, 103 and camming edges 104,
105.
It is clear that the clamping members 89, 90 can form integral
parts of the element 87 or that they can be permanently or
detachably affixed to this element. If the clamping members 89, 90
are integral with the element 87, the latter is simply provided
with internal camming edges 104, 105 and with the opening 110 for
the actuating bolt 109. If the material of the element 87 is
sufficiently rigid, the front end faces 95 of the clamping members
89, 90 need not abut against the end wall 88a. Furthermore, the
position of protuberances 91, 92 and recesses 93, 94 can be
reversed, and the connections between the element 87 and clamping
members 89, 90 can be established in a number of other ways, for
example, by grooving, by serrations similar to those shown at 22 in
FIG. 1, by keys, wedges and/or the like. It is also clear that the
couplings of FIGS. 1--4 can be utilized with equal advantage to
establish rigid but readily separable connections between solid
structural elements. In other words, and referring to FIG. 4, the
element 87 can be a solid piece of wood, metal or plastic which is
merely formed with an internal open-ended chamber or compartment
just large enough to accommodate the members 89, 90 and 96, 97.
Also, it suffices if the element 88 is formed with a relatively
shallow recess adjacent to the opening 108 and just deep enough to
permit entry of the hooks 98. 99.
FIG. 5 illustrates a further coupling serving to connect two hollow
or partially hollow structural elements 114, 115. These elements
are similar to the elements 1, 11 of FIG. 1. The coupling comprises
two clamping members 116, 117 and two locking members 118, 119. An
actuating bolt 120 is employed to spread the locking members 118,
119 apart and to thereby move the hooks or claws 127, 128 against
the innner side of an apertured end wall 115a of the element 115.
The bolt 120 extends through openings 121, 122 respectively
provided in a sidewall of the element 114 and in the clamping
member 116, and meshes with the locking member 118. Helical
expansion springs 123, 124 are respectively inserted between the
members 116, 118 and 117, 119 to bias the clamping members 116, 117
against the adjacent internal surfaces of the element 114 and to
simultaneously bias the locking members 118, 119 toward each other.
When the springs 123, 124 are free to expand, a projection 125 of
the locking member 118 extends into a complementary recess 126 of
the locking member 119 to establish a temporary connection between
the locking members. The positions of the projection 125 and recess
126 can be reversed. The projection 125 entrains the locking member
119 when the locking member 118 is shifted axially or lengthwise by
way of the actuating bolts 120, for example, to withdraw the hooks
127, 128 from the element 115. The end wall 115a of the element 115
has internal surfaces 129, 130 provided with camming edges 133, 134
which cooperate with sloping conical faces 131, 132 of the hooks
127, 128 to draw the end wall 115a against the adjoining end face
of the element 114 when the actuating bolt 120 is rotated in a
sense to move the locking members 118, 119 away from each
other.
The inner or rear end portions of locking members 118, 119 are
formed with followers 135, 136 which slide along tensioning cams
137, 138 of the clamping members 116, 117 when the locking members
begin to move away from each other. The followers 135, 136 cause
the clamping members 116, 117 to move in a direction to the right
and to bear against the outer side of the end wall 115a.
The clamping members 116, 117 and the locking members 118, 119 are
respectively provided with aligned rows of teeth 139, 140 which
respectively form two paris of tensioning racks adapted to engage
with each other when the locking members continue to move apart in
response to rotation of the actuating bolt 120. The flanks of teeth
139, 140 are less inclined than the sloping faces of followers 135,
136. This insures that the teeth 139 engage with the respective
teeth 140 when the locking members 118, 119 are moved sufficiently
away from each other, i.e., the teeth 139, 140 then take over from
the followers 135, 136 and relieve the pressure between these
followers and the cams 137, 138. This is of advantage because the
stresses developing between the members 116, 117 and 118, 119 are
distributed uniformly along a substantial part of the overall
length of the coupling. Furthermore, the teeth 139, 140 cooperate
with each other in such a way that the members 116--119 are not
subjected to appreciable bending or buckling stresses. It can be
said that the teeth 139, 140 constitute a second tensioning device
which is effective when the first tensioning device 135--138
effects a predetermined lengthwise displacement between the members
116, 117 and 118, 119 in response to continuing movement of locking
members away from each other. The outer sides of clamping members
116, 117 may but need not be provided with serrations or analogous
unevennesses.
FIG. 6 shows two hollow profiled structural elements 201, 202 which
are connected to each other by a coupling including two clamping
members 203, 204 and two locking members 205, 206. The clamping
members 203, 204 respectively comprise two relatively movable
portions or sections 207, 208 and 209, 210 which are articulately
connected to each other by rivets 211, 212 and leaf springs 213,
214. The free rear ends of springs 213, 214 extend inwardly beyond
the locking members 205, 206 and are connected to each other by a
rivet 215' or an analogous fastener. The springs 213, 214 are
stressed in such a way that their front end portions tend to bias
the locking members 205, 206 against each other, that their median
portions tend to bias the front sections 207, 209 of the clamping
members 203, 204 toward the adjoining internal surfaces of the
element 201, and that the rear sections 208, 210 remain spaced from
such internal surfaces. The sections 208, 210 engage with outwardly
extending flanges or followers 205a, 206a of the locking members
205, 206; these followers extend through openings 215, 216 provided
in the leaf springs 213, 214. The outer sides of the sections 207,
209 are toothed, knurled, milled or serrated, as at 217, 218, so
that they can bite into the adjoining portions of the element 201.
This element is formed with an opening 217a in registry with an
opening 218a in the clamping section 207 to permit insertion of an
actuating bolt 219 which meshes with the locking member 205 and can
move the locking members away from each other. The hooks 205b, 206b
at the front ends of the locking members 205, 206 then engage the
inner side of an apertured end wall 202a of the element 202
substantially in the same way as described in connection with the
preceding FIGS.
FIG. 6 shows the coupling in idle position. The hooks 205b, 206b
extend into the compartment 202b of the element 202 and begin to
move apart as soon as the actuating bolt 219 is rotated in a sense
to move the locking members 205, 206 away from each other. The
followers 205a, 206a shift the sections 207, 209 by way of sections
208, 210 so that the front end faces of the sections 207, 209 bear
against the outer side of the end wall 202a. As the bolt 219
continues to move the locking members 205, 206 away from each
other, the followers 205a, 206a cause the sections 208, 210 to
pivot toward the adjoining internal surfaces of the element 201 and
to thereby press the sections 207, 209 against the end wall 202a.
Buckling of the clamping members 203, 204 is prevented by leaf
springs 213, 214 and also because the one-piece locking members
205, 206 are then located close to the inner sides of the
respective sections 207, 208 and 209, 210.
It is clear that the fastener 215' can be omitted if the leaf
springs 213, 214 are integrally connected with each other or if
they are formed as a one-piece spring. Furthermore, the
configuration of clamping members 203, 204, locking members 205,
206 and/or springs 213, 214 can be changed in a number of ways
without departing from the spirit of my invention. For example,
each of the clamping sections 208, 210 can be articulately coupled
to or made integral with the adjoining locking member. Also the
sections 207, 209 can be fixed to or made integral with the element
201.
In this embodiment of my invention, the sections 208, 210 and
followers 205a, 206a together constitute a tensioning device
composed of two pairs of abutments which urge the hooks 205b, 206b
toward the clamping members 203, 204 when the actuating bolt 219
causes the locking members 205, 206 to move away from each other.
Such movement of locking members 205, 206 causes a flattening or
lengthening of clamping members 203, 204, i.e., the originally
arcuate or curved clamping members are caused to increase their
length when the sections 208, 210 pivot with reference to the
sections 207, 209.
In the embodiment of FIG. 7, two hollow structural elements 201A,
202A can be connected to each other by a coupling wherein two rigid
or slightly deformable locking members 223, 224 cooperate with a
clamping unit 222 whose clamping members 220, 221 constitute two
elastically deformable leaf springs. These leaf springs are
integral with each other and resemble a substantially U-shpaed body
provided with two tensioning prongs or cams 225, 226 which engage
followers 223a, 224a at the inner or rear ends of the locking
members 223, 224. The median portions of leaf springs 220, 221 form
two pairs of bulges which respectively engage the internal surfaces
of the element 201A and the outer sides of the locking members 223,
224. The followers 223a, 224a extend rearwardly through a cutout
227 in the clamping unit 222, such cutout being formed by slitting
and subsequent bending of the resulting tensioning prongs 225, 226.
Openings in the element 201A and leaf spring 220 permit insertion
of an actuating bolt 228 which meshes with the locking member 223
and can engage the locking member 224.
The operation of this coupling is similar to that of the coupling
shown in FIG. 6. The hooks 223b, 224b of locking members 223, 224
can engage that side of the wall 202B of the element 202A which
faces away from the open-ended chamber of the element 201A.
Referring now to FIGS. 8a--8c and 9a--9b, there is shown a further
coupling 232 which can be utilized to establish a connection
between two hollow structural elements 230, 231 so that the element
231 is normal to the element 230. FIGS. 8a, 8b and 8c respectively
illustrate the coupling 232 in a starting or idle position, in an
intermediate position and in a final or operative position. FIGS.
9a and 9b show two locking members 234, 233 which constitute the
locking unit of the coupling 232. The clamping unit includes two
elastically deformable clamping members each of which comprises two
leaf springs 235, 235' and 236, 236'. The front portions 237, 238
of the locking members 233, 234 form two hooks and the rear
portions of these locking members are reinforced, as at 239, 240.
These reinforced rear portions 239, 240 are respectively provided
with knife edges 241, 242 and with pairs of slots or grooves which
respectively accommodate the rear end portions of leaf springs 235,
235' and 236, 236'. When not accommodated in the element 230, the
front end portions of springs 235, 235' and 236, 236' extend away
from the respective locking members 233, 234 in a manner as shown
in FIGS. 9b and 9a so that they are spaced from the hooks 237,
238.
The locking members 233, 234 are respectively provided with bosses
243, 244 located between the leaf springs 235, 235' and 236, 236';
these bosses are respectively adjacent to the reinforced portions
239, 240 and extend forwardly toward the hooks 237, 238. The front
portions of the bosses 243, 244 are formed with transversely
extending knife edges 245, 246 respectively located at the level of
knife edges 241, 242. The boss 244 of the locking member 234 has a
tapped through bore to mesh with the stem of an actuating bolt 247
which extends outwardly through an opening 250 of the element
230.
When the coupling 232 is loosely inserted into the open-ended
chamber of the element 230, the reinforced end portions 239, 240 of
the locking members 233, 234 are hingedly or pivotally coupled to
each other. The front ends of the leaf springs 235, 235' and 236,
236' bear against the internal surfaces of the element 230 and
maintain the hooks 237, 238 close to each other (FIG. 8a). The
articulate connection between the reinforced end portions 239, 240
is established by transversely extending semicylindrical fulcra 249
provided on the locking members 233, 234 and extending into
complementary sockets or flutes 248. Each fulcrum 249 extends into
the socket 248 of the other locking member and can turn therein
through a predetermined angle to thus permit movement of hooks 237,
238 away from each other about the common axis of the fulcra 249.
The just described pivotal connection between the locking members
233, 234 was designed with a view to insure that both locking
members can be machined by resorting to a single tool or to a
single set of tools.
In FIG. 8a, the major part of the coupling 232 is accommodated in
the open-ended chamber of the element 230. The inner sides of the
locking members 233, 234 bear against each other under the action
of leaf springs 235, 235' and 236, 236' which are stressed in
response to insertion into and engagement with the element 230. The
free forward ends of the leaf springs bear against the outer side
of the element 231. This is achieved by shifting the locking
members 233, 234 by way of the actuating bolt 247. The opening 250
in the element 230 is large or long enough to permit such sidewise
displacement of the bolt 247.
When the operator rotates the bolt 247 to move the hooks 237, 238
away from each other, the locking members 233, 234 pivot about the
common axis of fulcra 249 and assume the intermediate positions
shown in FIG. 8b. The hooks 237, 238 engage the inner side of the
end wall 251 of the structural element 231. The knife edges 245,
246 of the bosses 243, 244 begin to penetrate into the adjoining
surfaces of the element 230 to thereby arrest the locking members
233, 234 against lengthwise displacement with reference to the
element 230. The leaf springs 235, 235' and 236, 236' undergo
gradually increasing deformation (compare FIGS. 8a and 8b).
The operator then continues to rotate the actuating bolt 247 so as
to move the locking members 233, 234 to the positions shown in FIG.
8c. The reinforced portions 239, 240 of the locking members are
spaced from each other, i.e., each fulcrum 249 is remote from the
respective socket 248. The leaf springs 235, 235' and 236, 236' are
subjected to maximal deforming stresses and bear against the end
wall 251 to thereby cooperate with the hooks 237, 238 in
maintaining the element 230 in a fixed position with reference to
the element 231. The knife edges 241, 242 have penetrated into the
element 230. The axis of the actuating bolt 247 makes with the
element 230 an acute angle during movement of the locking members
233, 234 from the starting positions of FIG. 8a to the final
positions of FIG. 8c, but such axis is normal or nearly normal to
the element 230 in the positions shown in FIGS. 8a and 8c. In FIGS.
8a--9b, the rear end portions of springs 235--236' and the
reinforced portions 239, 240 together constitute a tensioning
device which urges the hooks 237, 238 toward the leaf springs when
the actuating bolt 247 moves the locking members 233, 234 from
first positions (FIG. 8a) toward second positions (FIG. 8c).
In each of the illustrated embodiments, the actuating bolt merely
serves as a means for moving the locking members with reference to
each other. Therefore, this actuating bolt need not be supported by
the respective structural element and/or by the clamping unit of
the corresponding coupling. Consequently, the openings or passages
provided for the actuating bolt in the corresponding structural
element and in the adjoining clamping member need not be machined
with a high degree of precision and the areas of such openings can
be readily selected in such a way that the entire coupling can be
withdrawn into or partially expelled from the element in which the
major part of the coupling is accommodated prior to connection to
the other element. It is further clear that the improved coupling
can be used to connect two or more structural elements of circular
or oval outline and/or to connect an element of substantially
circular outline with an element of polygonal outline. In other
words, the coupling can be used for connection of rods, bars,
tubes, sleeves, cylinders, pipes or the like. The clamping members
are then preferably provided with convex outer faces so that they
can be properly fitted into a chamber of substantially circular
outline.
Another important advantage of the improved coupling is that it can
be inserted into a structural element at the locale of sue so that
elements to be connected thereby can be transported in dismantled
condition. All that is necessary to provide one of the elements
with an aperture which can permit passage of hooks at the forward
ends of the locking members and to further provide such one element
with a wall (such as the wall 10 of FIG. 1) which can be engaged by
the hooks in response to movement of corresponding locking members
with reference to each other. The coupling can be inserted into the
other element (e.g., the element 1 of FIG. 1) at the manufacturing
plant or at the locale of use. If the hollow structural element 11
of FIG. 1 does not have an end wall 10, an apertured end wall can
be affixed thereto by resorting to rivets, screws, nails or other
types of fasteners. Furthermore, the end portion of the element 11
shown in FIG. 1 (or of the corresponding elements shown in FIGS.
2--8c) can be of spherical or semispherical outline. As stated
before, the intermediate element 62 of FIG. 3 can also resemble a
cylinder, a sphere or another body of other than polygonal outline.
The element 1 (or the corresponding elements shown in FIGS. 2--8c)
should be provided with an open-ended internal chamber to
accommodate the coupling prior to and during connection to the
adjoining element. The bolts shown in FIGS. 1 to 9b constitute but
one form of actuating means which can be utilized in my coupling.
For example, such bolts can be replaced by suitable wedges which
are forcibly introduced between the locking members. Furthermore,
one can resort to eccentrics which are inserted between the locking
members to move them apart in response to angular displacement from
a starting position. Still further, it is possible to employ in the
coupling an actuating means which includes a explosive charge
adapted to be ignited by remote control (e.g., by heating) to
thereby move the locking members with reference to each other. Such
types of actuating means can be employed if it is desirable to omit
the openings shown in the drawings for introduction and
manipulation of the bolts. The locking members are then designed in
such a way that they automatically remain in spaced-apart positions
which they assume in response to ignition or detonation of the
explosive charge. The charge can be ignited or detonated by
resorting to electrical resistance heating. Encapsulated liquid gas
can be used as a substitute for an explosive charge. All such
modifications are so obvious that they will be readily understood
upon perusal of the preceding description without necessitating
reference to additional drawings.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can, by applying current
knowledge, readily adapt it for various applications without
omitting features which fairly constitute essential characteristics
of the generic and specific aspects of my contribution to the art
and, therefore, such adaptations should and are intended to be
comprehended within the meaning and range of equivalence of the
claims.
* * * * *