Information
-
Patent Grant
-
6308412
-
Patent Number
6,308,412
-
Date Filed
Wednesday, December 31, 199726 years ago
-
Date Issued
Tuesday, October 30, 200122 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Rosenbaum; I Cuda
- Nguyen; T.
Agents
- MacMillan, Sobanski & Todd, LLC
-
CPC
-
US Classifications
Field of Search
US
- 280 796
- 280 795
- 029 8972
- 029 8973
- 029 897312
- 029 4211
- 029 428
- 029 897
- 072 58
- 072 61
- 072 62
- 228 177
- 228 178
-
International Classifications
-
Abstract
A method of manufacturing a vehicle frame assembly includes the initial steps of providing first and second side rails and providing first and second cross members. Each of the first and second cross members has first and second ends extending from a central portion. A desired torsional stiffness is determined for the first cross member. In response to this determination, the first and second ends of the first cross member are enlarged so as to achieve the desired torsional stiffness for the cross member. A similar process can be conducted for the second cross member. Then, the first ends of the first and second cross members are secured to the first side rail, and the second ends of the first and second cross members are secured to the second side rail to form a vehicle frame assembly.
Description
BACKGROUND OF THE INVENTION
This invention relates in general to vehicle frame components and in particular to an improved structure for a joint between a cross member and a side rail in a vehicle frame assembly, wherein the cross member has ends that are circumferentially enlarged relative to a central portion thereof, and wherein the enlarged ends extend to or through the side rail of the frame assembly.
Virtually all land vehicles in common use, such as automobiles and trucks, include a frame which serves as a platform upon which the remainder of the vehicle is built. Many vehicle frame structures are known in the art. Most of these known vehicle frame structures are formed from a number of individual metallic components which are permanently joined together. For example, a typical full perimeter vehicle frame assembly includes a pair of longitudinally extending side rails which are joined together at the front by a forward cross member, at the rear by a rearward cross member, and at intermediate locations by one or more intermediate or auxiliary cross members. The cross members not only connect the two side rails together, but also provide desirable lateral, vertical, and torsional rigidity to the vehicle frame assembly. In some vehicle frame assemblies, the side rails are formed from open channel structural members, i.e., structural members which have a non-continuous cross sectional shape (U-shaped or C-shaped channel members, for example). In other vehicle frame assemblies, the side rails are formed from closed channel structural members, i.e., structural members which have a continuous cross sectional shape (box-shaped or tubular channel members, for example). Regardless of the specific structure of the structural members, the side rails and cross members, once joined together, form a rigid frame for supporting the remaining portions of the vehicle thereon.
Typically, the cross members extend transversely relative to the two parallel side rails, and the ends of the cross members are permanently secured to the side rails at joints to form a generally rectangular vehicle frame assembly. In some instances, the joints between the cross members and the side rails are sufficiently strong that the ends of the cross members can be secured directly to the side rails, such as by welding, rivets, bolts, and the like. In other instances, the ends of the cross members are connected by brackets or similar reinforcing structures to the side rails. In these latter instances, it has been found that the use of such additional brackets or similar reinforcing structures adds undesirable cost and complexity to the vehicle frame assembly. Thus, it would be desirable to provide an improved structure for a joint between a cross member and a side rail in a vehicle frame assembly that eliminates the need for such brackets or similar reinforcing structures.
SUMMARY OF THE INVENTION
This invention relates to an improved structure for a joint between a cross member and a side rail in a vehicle frame assembly that eliminates the need for brackets or similar reinforcing structures to increase the strength thereof. The vehicle frame assembly includes a pair of longitudinally extending side rails and having at least one cross member extending transversely therebetween. The side rails are hollow members including inner and outer side walls. The ends of the cross member are enlarged circumferentially relative to a central portion thereof. Each of the enlarged ends extends to or through the side rail of the frame assembly and is secured thereto. In a first embodiment, the enlarged ends of the cross member extend through both the inner and outer walls of the side rails and are secured thereto, such as by welding. In a second embodiment, the enlarged ends of the cross member extend through only the inner walls of the side rail and are secured thereto, such as by welding. In a third embodiment, the enlarged ends of the cross member are disposed adjacent to the inner walls of the cross member and secured thereto, such as by welding.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view of a portion of a full perimeter or ladder type vehicle frame assembly in accordance with this invention.
FIG. 2
is a perspective view of one of the cross members illustrated in FIG.
1
.
FIG. 3
is a sectional elevational view of a first embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
FIG. 4
is a sectional elevational view similar to
FIG. 3
of a second embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
FIG. 5
is a sectional elevational view similar to
FIG. 3
of a third embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
FIG. 6
is a sectional elevational view similar to
FIG. 3
of a fourth embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
FIG. 7
is a sectional elevational view similar to
FIG. 3
of a fifth embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
FIG. 8
is a sectional elevational view similar to
FIG. 3
of a sixth embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
FIG. 9
is a sectional elevational view similar to
FIG. 3
of a seventh embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
FIG. 10
is a sectional elevational view similar to
FIG. 3
of a eighth embodiment of a joint between the cross member and the side rail illustrated in FIG.
1
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, there is illustrated in
FIG. 1
a portion of a full perimeter or ladder type vehicle frame assembly, indicated generally at
10
, in accordance with this invention. The illustrated vehicle frame assembly
10
includes two longitudinally extending side rails
11
and
12
. As is well known, the side rails
11
and
12
preferably extend throughout most or all of the length of the vehicle. However, it is also known to provide side rails
11
and
12
that extend throughout only a portion of the length of the vehicle. Each of the side rails
11
and
12
is preferably formed from a single relatively long piece of material. Alternatively, each of the side rails
11
and
12
may be formed from two or more relatively short pieces of material that are secured together in a conventional manner, such as by welding.
The illustrated side rails
11
and
12
are hollow members having a generally rectangular or box-shaped cross sectional shape, as best shown in FIG.
3
. Thus, the illustrated side rails
11
and
12
each have an inner wall
21
and an outer wall
22
. This cross sectional shape is advantageous not only because it provides strength and rigidity, but also because it provides vertically and horizontally oriented side surfaces that facilitate the attachment of various brackets and mounts (not shown) used to support other components of the vehicle on the vehicle frame structure
10
. In the illustrated embodiment, the side rails
11
and
12
are formed from closed channel stock having a tubular or rectangular cross sectional shape. However, the side rails
11
and
12
may be formed from two pieces of U-shaped or C-shaped stock that are oriented so as to face inwardly toward one another and are secured together in a conventional manner, such as by welding. Typically, the side rails
11
and
12
are formed from steel or other suitable metallic materials. However, other materials, such as aluminum, composites (such as fiber matrix composites) or combinations thereof, may be used and shaped as desired using alternative methods, such as extrusion or pultrusion.
If tubular stock is used to form the side rails
11
and
12
, the tubular stock may be formed into a desired shape in any conventional manner. For example, hydroforming may be used to form the side rails
11
and
12
to have the illustrated generally rectangular cross sectional shape. Hydroforming is a well known process that uses pressurized fluid to deform, expand, or re-shape a tubular member into a desired shape. In a known high pressure hydroforming process, the tubular member is initially disposed between two die sections of a hydroforming apparatus which, when closed together, define a die cavity having a desired final shape. Although the die cavity is usually somewhat larger than the tubular member itself and non-circular in cross sectional shape, the closure of the two die sections may, in some instances, cause some mechanical deformation of the tubular member. Thereafter, the tubular member is filled with a pressurized fluid, typically a relatively incompressible liquid such as water. The pressure of the fluid is increased to a magnitude where the tubular member is expanded outwardly into conformance with the die cavity. As a result, the tubular member is expanded into the desired final shape. In a known low pressure hydroforming process, the tubular member is initially filled with fluid at a relatively low pressure. Then, the tubular member is disposed between two die sections of a hydroforming apparatus which, when closed together, define a die cavity having a desired final shape. The closure of the two die sections causes deformation of the tubular member to as to conform with the die cavity. As a result, the tubular member is re-shaped into the desired final shape. It should be noted that the sequence of steps in either of the hydroforming processes may vary from that specifically described herein.
One or more cross members, indicated generally at
13
, extend transversely between the side rails
11
and
12
to form the vehicle frame assembly
10
upon which the remainder of the vehicle is supported. In the illustrated embodiment, three of such cross member
13
are extend transversely at the front, center, and rear portions of the vehicle frame assembly
10
. However, any desired number of cross members
13
may be provided. Each of the cross members
13
is preferably formed from a single relatively long piece of material that extends completely between the side rails
11
and
12
. Alternatively, the cross members
13
may be formed from two or more relatively short pieces of material that are secured together in a conventional manner, such as by welding.
Referring now to
FIGS. 2 and 3
, it can be seen that the front and rear cross members
13
are hollow members having a generally circular cross section. Although the illustrated cross members
13
have a generally circular cross section, it will be appreciated that the cross members
13
may be formed to have any desired cross sectional shape, such as square, rectangular, or polygonal. Each of the cross members
13
is formed having a pair of ends
14
and
15
that are somewhat larger in dimension than a central portion
16
thereof In the illustrated embodiment, the central portion
16
has a relatively constant diameter, although such is not necessary. The outer diameter of the cross member
13
increases in transition regions
17
and
18
extending respectively between the ends of the central portion
16
and the two enlarged ends
14
and
15
of the cross member
13
. Preferably, the transition areas
17
and
18
taper gradually from the ends of the central portion
16
and the enlarged ends
14
and
15
of the cross member
13
. The enlarged ends
14
and
15
of the cross member
13
terminate in respective outer edges
19
. In the illustrated embodiment, the enlarged ends
14
and
15
have a relatively constant diameter, although again such is not necessary.
In the embodiment illustrated in
FIG. 3
, the outer dimension (the outer diameter in the illustrated cross member
13
having a circular cross sectional shape) of the enlarged ends
14
and
15
is maximized in response to several factors. One factor is the size of the inside wall
21
and the outside wall
22
of the side rails
11
and
12
. As is known in the art, sufficient surface area should be left on the inside wall
21
and/or the outside wall
22
of the side rails
11
and
12
to provide structural support and an area to secure the cross member
13
thereto, as will be explained below. Another factor is the size of the enlarged ends
14
and
15
which may, in turn, be limited by the size and clearances of other vehicle components which are adjacent the cross member
13
or to the side rails
11
and
12
. For example, if the central portion
16
has a outer circumference of about 3.00 inches, the circumference of the ends
14
and
15
could be about 3.75 inches. Preferably, the enlarged ends
14
and
15
are formed using a hydroforming process. Alternatively, other manufacturing methods which are known to those skilled in the art may be used to form a cross member
13
having ends
14
and
15
which are enlarged circumferentially relative to a central portion
16
thereof.
This invention contemplates that several cross member to side rail attachment configurations may be used to provide sufficient attachment or joint strength. In general, joint strength includes structural performance characteristics, such as stress distribution and magnitude, stiffness, and fatigue performance. In the first embodiment shown in
FIG. 3
, the enlarged end
14
of the cross member
13
extends through a pair of openings
20
a
and
20
b
formed through the inner wall
21
and the outer wall
22
of the side rail
12
. Similarly, the enlarged end
15
of the cross member
13
extends through a pair of openings (not shown) formed through the inner wall
21
and the outer wall
22
of the other side rail
11
. If the cross member
13
is generally straight as shown, the openings
20
a
and
20
b
formed through the side rail
12
will be generally transversely aligned with the openings formed through the side rail
11
. Alternatively, the cross member
13
may have a bend (not shown) formed therein such that it is does not extend generally straight In that instance, the openings
20
a
and
20
b
formed through the side rail
12
may be transversely offset from the openings formed through the side rail
11
.
The openings
20
a
and
20
b
are shaped to correspond to the cross sectional shape of the enlarged ends
14
and
15
of the cross members
13
and are slightly larger in size. Generally, the size of the enlarged ends
14
and
15
is maximized, while taking into consideration limitations associated with the manufacturing process and the size of the side rails
11
and
12
. In a preferred embodiment, the cross members
13
are formed using a hydroforming process. Using this type of manufacturing process, the enlarged ends
14
and
15
of a particular cross member
13
may have an outer size in the range of from about 5% to about 50% larger than the outer size of the central portion
16
thereof.
The relationship between the size of the enlarged ends
14
and
15
of the cross member
13
relative to the size of the central portion
16
can be significant in determining the relative torsional stiffness of the vehicle frame assembly
10
. It has been found that by varying the relationship between these sizes, the torsional stiffness of the cross member
13
can be adjusted to provide a desired torsional stiffness to the vehicle frame assembly. These relative sizes can be expressed in any conventional units, such as perimeter, diameter, and the like. Specifically, if the size of the enlarged ends
14
and
15
of the cross member
13
is relatively close to the size of the central portion
16
, the torsional stiffness of the cross member
13
will be increased. As the size of the enlarged ends
14
and
15
of the cross member
13
is increased relative to the size of the central portion
16
, the torsional stiffness of the cross member
13
will be decreased. Similarly, the wall thickness of the enlarged ends
14
and
15
and the central portion
16
of the cross member
13
can be significant in determining the relative torsional stiffness of the vehicle frame assembly
10
. It has been found that the torsional stiffness of the cross member
13
increases with the wall thickness of the enlarged ends
14
and
15
and the central portion
16
thereof.
As best shown in
FIG. 3
, the cross member
13
is inserted in the openings
20
a
and
20
b
such that the enlarged end
14
passes through the inside wall
21
of the side rail
12
until its outer edge
19
extends slightly beyond with the outside wall
22
of the side rail
12
. The cross member
13
is then secured to the side rail
12
, such as by welding
23
. The welding
23
may extend completely about the enlarged end
14
of the cross member
13
or may extend discontinuously thereabout. Preferably, the welding
23
is made between the inside wall
21
of the side rail
12
and the enlarged end
14
of the cross member
13
and also between the outside wall
22
of the side rail
12
and the enlarged end of the cross member
13
, although such is not necessary. Alternatively, is the cross member
13
may be secured to the side rail
12
using other known methods, such as adhesives. The other enlarged end
15
of the cross member
13
can be secured to the side rail
11
in a similar manner.
Referring now to
FIG. 4
, there is illustrated a second embodiment of a joint between a cross member and a side rail of the vehicle frame assembly
10
in accordance with this invention. In this embodiment, a modified side rail
30
is provided in lieu of the side rail
12
. The modified side rail
30
is formed having an inside wall
31
and an outside wall
32
. Respective openings
33
a
and
33
b
are formed through the inside wall
31
and the outside wall
32
of the side rail
30
. The outside wall
32
further has a relatively short flange portion
32
a
formed about the opening
33
b
. A modified cross member, indicated generally at
35
, is provided in lieu of the cross member
13
. The modified cross member
35
includes a central portion
36
, a transition portion
37
, and an enlarged end
38
. The enlarged end
38
of the cross member
35
extends through the openings
33
a
and
33
b
and through the flange portion
32
a
. The openings
33
a
and
33
b
and the flange portion
32
a
are shaped to correspond to the cross sectional shape of the enlarged end
38
of the cross member
35
and is slightly larger in size. The cross member
35
is then secured to the side rail
30
, such as by welding
39
. The flange portion
32
a
improves the welding process and can facilitate assembly of the cross member
35
with the side rail
30
.
Referring now to
FIG. 5
, there is illustrated a third embodiment of a joint between a cross member and a side rail of the vehicle frame assembly
10
in accordance with this invention. In this embodiment, a modified side rail
40
is provided in lieu of the side rail
12
. The modified side rail
40
is formed having an inside wall
41
and an outside wall
42
. Respective openings
43
a
and
43
b
are formed through the inside wall
41
and the outside wall
42
of the side rail
40
. The opening
43
a
formed through the inside wall
41
is relatively small in size, while the opening
43
b
formed through the outside wall
42
is relatively large. The outside wall
42
further has a relatively short flange portion
42
a
formed about the opening
43
b
. A modified cross member, indicated generally at
45
, is provided in lieu of the cross member
13
. The modified cross member
45
includes a central portion
46
, a first transition portion
46
a
, an enlarged intermediate portion
47
, a second transition portion
47
a
, and a further enlarged end
48
. The enlarged end
48
of the cross member
45
extends through the flange portion
42
a
and through the opening
43
b
formed through the outside wall
42
. The intermediate portion
47
extends through the opening
43
a
formed through the inside wall
41
. The opening
43
b
and the flange portion
42
a
are shaped to correspond to the cross sectional shape of the enlarged end
48
of the cross member
45
and are slightly larger in size. Similarly, the opening
43
a
is shaped to correspond to the cross sectional shape of the intermediate portion
47
of the cross member
45
and is also slightly larger in size. The cross member
45
is then secured to the side rail
40
, such as by welding
49
.
Referring now to
FIG. 6
, there is illustrated a fourth embodiment of a joint between a cross member and a side rail of the vehicle frame assembly
10
in accordance with this invention. In this embodiment, a modified side rail
50
is provided in lieu of the side rail
12
. The modified side rail
50
is formed having an inside wall
51
and an outside wall
52
. Respective openings
53
a
and
53
b
are formed through the inside wall
51
and the outside wall
52
of the side rail
50
. The opening
53
a
formed through the inside wall
51
is relatively large in size, while the opening
53
b
formed through the outside wall
52
is relatively small. The inside wall
51
further has a relatively short flange portion
51
a
formed about the opening
53
a
. A modified cross member, indicated generally at
55
, is provided in lieu of the cross member
13
. The modified cross member
55
includes a central portion
56
, a first transition portion
56
a
, an enlarged intermediate portion
57
, a second transition portion
57
a
, and an end
58
that is somewhat smaller than the intermediate portion
57
but larger than the central portion
56
. The end
58
of the cross member
55
extends through the opening
53
b
formed through the outside wall
52
. The intermediate portion
57
extends through the flange portion
51
a
and the opening
53
a
formed through the inside wall
51
. The opening
53
b
is shaped to correspond to the cross sectional shape of the end
58
of the cross member
55
and is slightly larger in size. Similarly, the opening
53
a
is shaped to correspond to the cross sectional shape of the flange portion
51
a
and the intermediate portion
57
of the cross member
55
and are also slightly larger in size. The cross is member
55
is then secured to the side rail
50
, such as by welding
59
.
Referring now to
FIG. 7
, there is illustrated a fifth embodiment of a joint between a cross member and a side rail of the vehicle frame assembly
10
in accordance with this invention. In this embodiment, a modified side rail
60
is provided in lieu of the side rail
12
. The modified side rail
60
is formed having an inside wall
61
and an outside wall
62
. An opening
63
is formed through the inside wall
61
of the side rail
60
. A modified cross member, indicated generally at
65
, is provided in lieu of the cross member
13
. The modified cross member
65
includes a central portion
66
, a transition portion
67
, and an enlarged end
68
. The enlarged end
68
of the cross member
65
extends through the opening
63
formed through the inside wall
61
and terminates in the interior of the side rail
60
. The opening
63
is shaped to correspond to the cross sectional shape of the enlarged end
68
of the cross member
65
and is slightly larger in size. The cross member
65
is then secured to the side rail
60
, such as by welding
69
.
Referring now to
FIG. 8
, there is illustrated a sixth embodiment of a joint between a cross member and a side rail of the vehicle frame assembly
10
in accordance with this invention. In this embodiment, a modified side rail
70
is provided in lieu of the side rail
12
. The modified side rail
70
is formed having an inside wall
71
and an outside wall
72
. An opening
73
is formed through the inside wall
71
of the side rail
70
. The inside wall
71
further has a relatively short flange portion
71
a
formed about the opening
73
. A modified cross member, indicated generally at
75
, is provided in lieu of the cross member
13
. The modified cross member
75
includes a central portion
76
, a transition portion
77
, and an enlarged end
78
. The enlarged end
78
of the cross member
75
extends through the opening
73
formed through the inside wall
71
and the flange
71
a
and terminates in the interior of the side rail
70
. The opening
73
and the flange
71
a
are shaped to correspond to the cross sectional shape of the enlarged end
78
of the cross member
75
and are slightly larger in size. The cross member
75
is then secured to the side rail
70
, such as by welding
79
.
Referring now to
FIG. 9
, there is illustrated a seventh embodiment of a joint between a cross member and a side rail of the vehicle frame assembly
10
in accordance with this invention. In this embodiment, a modified side rail
80
is provided in lieu of the side rail
12
. The modified side rail
80
is formed having an inside wall
81
and an outside wall
82
. An opening
83
is formed through the inside wall
81
of the side rail
80
. The inside wall
81
further has a relatively short flange portion
81
a
formed about the opening
83
. A modified cross member, indicated generally at
85
, is provided in lieu of the cross member
13
. The modified cross member
85
includes a central portion
86
, a transition portion
87
, and an enlarged end
88
. The enlarged end
88
of the cross member
85
extends about the flange
81
a
. The flange
81
a
is shaped to correspond to the cross sectional shape of the enlarged end
88
of the cross member
85
and are slightly smaller in size. The cross member
85
is then secured to the side rail
80
, such as by welding
89
.
Referring now to
FIG. 10
, there is illustrated an eighth embodiment of a joint between a cross member and a side rail of the vehicle frame assembly
10
in accordance with this invention. In this embodiment, a modified side rail
90
is provided in lieu of the side rail
12
. The modified side rail
90
is formed having an inside wall
91
and an outside wall
92
. A modified cross member, indicated generally at
95
, is provided in lieu of the cross member
13
. The modified cross member
95
includes a central portion
96
, a transition portion
97
, and an enlarged end
98
. The enlarged end
98
of the cross member
95
extends into abutment with the inside wall
91
. The cross member
95
is then secured to the side rail
90
, such as by welding
99
.
In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiments. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.
Claims
- 1. A method of manufacturing a vehicle frame assembly comprising the steps of:(a) providing first and second side rails; (b) providing first and second cross members, each of the first and second cross members having first and second ends extending from a central portion; (c) determining a desired torsional stiffness for the first cross member; (d) in response to said determination, enlarging the first and second ends of the first cross member so as to achieve the desired torsional stiffness for the cross member; and (e) securing the first ends of the first and second cross members to the first side rail and the second ends of the first and second cross members to the second side rail to form a vehicle frame assembly.
- 2. The method defined in claim 1 wherein said step (d) is performed by hydroforming.
- 3. The method defined in claim 1 wherein said step (d) is performed by increasing the perimeter of the first and second ends of the first cross member.
- 4. The method defined in claim 1 wherein said step (d) is performed by increasing the size of the first and second ends of the first cross member from about 5% to about 50%.
- 5. The method defined in claim 1 wherein said step (d) is performed by decreasing the wall thickness of the first and second ends of the first cross member.
- 6. The method defined in claim 1 wherein said step (e) is performed by forming an opening through each of the first and second side rails and inserting the first and second ends of the first cross member respectively through the openings.
- 7. The method defined in claim 6 wherein said step (e) is performed by forming a flange about each of the openings and inserting the first and second ends of the cross member within the flanges.
- 8. The method defined in claim 6 wherein said step (e) is performed by forming a flange about each of the openings and inserting the first and second ends of the cross member about the flanges.
- 9. The method defined in claim 1 wherein said step (e) is performed by forming first and second openings through each of the first and second side rails and inserting the first and second ends of the first cross member respectively through the first and second openings.
- 10. The method defined in claim 9 wherein said step (e) is performed by forming a flange about the first openings formed through the first and second side rails and inserting the first and second ends of the cross member within the flanges.
- 11. The method defined in claim 9 wherein said step (e) is performed by forming a flange about the first openings formed through the first and second side rails and inserting the first and second ends of the cross member about the flanges.
- 12. The method defined in claim 7 wherein said step (e) is performed by forming the first and second openings having different sizes.
- 13. The method defined in claim 1 wherein said step (e) is performed by disposing the first and second ends of the cross member in abutment with the first and second side rails.
- 14. The method defined in claim 1 wherein said step (e) is performed by welding.
US Referenced Citations (15)
Foreign Referenced Citations (1)
Number |
Date |
Country |
691329 |
May 1953 |
GB |