US2886344A - Tow bar - Google Patents

Description

12, 1959 J. M. BEACH ET AL 2,886,344

TOW BAR Filed Oct. 10, 1955 2 Sheets-Sheet l mmvrox. JOHN M; 51mm? BY f M- W ZEPB R) y 1959 J. M. BEACH ETAL 2,886,344

TQW BAR Filed Oct. 10, 1955 2 Sheets-Sheet 2 INVENTOR. JOHN M. 5640/"? BY JAMES w BR/IDBURY TOW BAR John M. Beach and James W. Bradbury, Dayton, Ohio;

said Bradbury assignor to said Beach Application October 10, 1955, Serial No. 539,418

7 Claims. (Cl. 280482) This invention relates to a tow bar and more particularly to a tow bar for towing a trailing vehicle by a tractor, although not necessarily so limited.

Various types of tow bars and hitches have been used forconnecting a trailer, airplane, farm machinery, earthmoving equipment, et cetera, to a tractor. These have been made out of various types of materials, some of them being made from wood and others from metal. 7 An object of this invention is to provide a tow bar made from hollow metallic members, so designed as to have great strength; but at the same time to be light in weight, economical to produce and efiicient.

Another object of this invention is to provide a tow bar which has telescoping members permitting the length of the tow bar to be adjusted as desired.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of opera tion, as will become more apparent from the following description.

In the drawings,

Figure l is a perspective view of a tow bar.

Figure 2 is a top plan View.

Figure 3 is a side elevational view.

Figure 4 is a cross sectional view taken substantially on the line 44 of Figure 3.

Figure 5 is a perspective view of a modification of the tow bar.

Figure 6 is a top plan view of an inner telescoping member of the modification.

Figure 7 is a top plan view of an outer telescoping member of the modification.

Figure 8 is a cross sectional View, taken substantially along the line 8-8 of Figure 7.

Figure 9 is a cross sectional view, taken substantially along the line 9-9 of Figure 7.

Figure vl0 is a cross sectional view, taken substantially along the line 1010 of Figure 6.

Figure 11 is a cross sectional view of a pin assembly for locking together the two telescoping members.

Referringto the drawings in detail, the reference character 10 indicates the main body of a tow bar. This body simulates an ellipse in cross sectional area, as clearly shown in Figure 4. The forward end of this bar is welded to a hollow toroidal ring, that is, a doughnut-shaped ring, 12. This ring 12 is made from two halves 14 and 16. The two halves 14 and 16 are welded together along an outer seam 18 and an inner seam 20. The cross sectional area taken through one side of the ring or loop 12 is circular.

The contour of member 10 is identical to the outline of a section taken on a line AA of the toroidal member 12. The main body 10 is a drawn steel tubular member, drawn to a shape corresponding to the shape of the section of the toroidal member 12 taken on the section line A-A. One end of the tubular member terminates in a plane perpendicular to the longitudinal axis of member 10. This end of the tubular member overlies the contiguous surface of the toroidal member 12, so that a portion of member 12 projects into the tubular member 10 as shown in dotted lines in Figure 2. Member 10 is welded to member 12 along the welded seam 22 lying on one plane. This arrangement results in a strong juncture between members 10 and 12.

The end of member 10 opposite the toroidal member 12 is welded to a tubular member 30. The diameter of the tubular member 30 is approximately equal to the maximum vertical thickness of member 10. The tubular member 30 may be somewhat longer than the maximum width of member 10. The length of member 30 depends entirely upon the nature of the load to be towed. The tubular member is welded to member 10 along an arcuate seam 32.

A pair of bushings 34 are each provided with a rabbet upon which an end 36 of the tubular member 30 projects. The bushings 34 are welded to the tubular member along a circular weld 40. The bushings 34, together with the tubular member 30, define a. pivotal axis for the tow bar which is parallel to the major elliptical axis of the member 30.

The resulting structure is light in weight, due to the shape of the main body of the tow bar. It is strong and cannot easily be deflected, especially laterally. The hollow toroidal ring provides a strong eye that is light in weight and is easily connected to a coupling member on the tractor.

In the modification disclosed in Figures 5 to '10, a hollow tubular member 54 having an elliptical cross section, is welded to a hollow toroidal ring 52, as described hereinbefore. Passing through the tubular member in a direction normal to the plane of the toroidal ring 52 are a pair of holes 54 and 56, one near each end of the tubular member 50. The holes 54 and 56 are lined with a spool 58 as indicated in Figure 10. As clearly seen in Figure 10, the margins of the holes 54 and 56 have been spun over the end of the inner ends of the spools 58, so as to hold the spools in position. The end of the tubular member 50 opposite the toroidal ring 52 is closed with an oval-shaped planar cap 60 welded in place.

A second tubular member 62, similar in length to the tubular member 50, but having a slightly larger oval crosssection, is adapted to telescope over the first tubular member 50. Encircling one end of the tubular member 62 is a belt 64 having a projection 66 to which is welded an eye 68 for engaging a chain 70. A second belt 72 encircles the tubular member 62 a short distance from the first belt 64. Both belts 641 and 72 are welded in place. The belt 72 has a pair of oppositely disposed projections 74 and 76, which are penetrated by a hole 78, which also penetrates the tubular member 62, as shown in Figure 9.

Welded to and closing the end of tubular member 62 opposite the belts 64 and 72 is a U-shaped coupler 80, having a pair of coaxial holes 82 and 84, one located in each straight leg of the U-shaped coupler, so as to accept a coupling shaft or pin (not shown), to which the tubular member 62 may be pivotally attached. As clearly illus trated in the drawing, the'pivotal axis defined by the coupler is parallel to the major elliptical axes of the members 50 and 62. The elliptical welded seam joining the U-shaped coupler 80 to the tubular member 62 is strengthened by a brace 86 welded inside the tubular member 62 and also welded to the U-shaped coupler 80.

When the tubular member 62 is telescoped over the tubular member 50, the hole 78, penetrating the tubular member 62, may be registered with either the hole 54 near the toroidal ring 52 in the tubular member 50, or the hole 56 near the opposite end of the tubular member 50. The two tubular members 50 and 62 may be locked together in one of two positions by passing a pin, such as a hollow pin 88, through the aligned holes 78 and 54 to form a short tow bar or 78 and 56 to form along tow bar.

An elongate spring wire clip 90 and a washer 92 are used to position and retain the pin 88 within the aligned holes. The spring wire clip 90 has a loop 94 at one end having a diameter larger than the diameter of the hollow pin 88 and resilient flared out portions or ends 96 at the other end. The clip 90 can be projected through the washer 92 and the hollow pin 88 by compressing the flared ends 96. The flared ends 96 spread out after they have passed through the pin 88, thereby securing the clip 90 and the washer 92 to the pin 88. Notches 98 in the pin 88 engage the flared portions 96, so that the clip 90 cannot be removed from the pin 88 without first compressing the flared ends 96. When the pin 88 and clip 90 have been inserted in a pair of aligned holes, as for example, holes 78 and 56, the flared out portions 96 spread apart to hold the assembly in place. The pin assembly can be removed from the tow bar by pulling on the loop 94 of the clip 90. This action does not, however, separate the clip 90 and the pin 88, for the reason that the notches 98 are in engagement with the flared ends 96 of the clip 99. The chain 70 is linked to the clip 90 to prevent loss of the clip and pin assembly.

This modification has the advantage that a relatively long tow bar, which is both strong and light in weight, can be collapsed to nearly half its original length for storage and shipping.

Although the preferred embodiments of the device have been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described our invention, we claim:

1. In a tow bar, a pair of telescoping oval-shaped tubular members, one member having a hole directed normal to its longest axis, the other member having two holes similarly directed, it being possible to register the hole in the one member with either of the holes in the other member, a pin projectable through the registered holes so as to lock said tubular members together, the length of the telescoped members so locked being determined by the location of the holes, a toroidal hollow ring attached to an end of one of the telescoping members and a coupler attached to an end of the other telescoping member, the toroidal ring and the coupler being at oppositeends of the tow bar.

2. A tow bar including a pair of telescoping oval-shaped tubular mmbers, the inner of said telescoping tubular members having a plurality of spaced pairs of opposing aligned apertures in the wall thereof, each pair of apertures being aligned along the shortest diameter of said member, a plurality of spool elements secured within said inner member and extending parallel to the shortest diameter of said inner member, there being one spool element aligned with each said pair of apertures, the outer of said telescoping tubular members having a pair of opposing apertures in the wall thereof aligned along the shortest diameter thereof, the construction and arrangement being such that the apertures in said outer member may be placed in registry with any pair of aligned apertures in said inner member, and pin means projectable through said registered apertures for locking said tubular members in fixed telescoping relation.

3. The tow bar according to claim 2 wherein the marginal portions of said inner member adjacent the apertures therein are swaged inwardly into the spool elements aligned therewith.

4. A tow bar comprising a hollow elongate body substantially elliptical in cross section, first means disposed at one end of said body for engaging a towing vehicle, and second means disposed at the opposite end of said body for pivotally securing said body to a vehicle which is to be towed, said second means defining a pivotal axis for said body which is substantially parallel to the major elliptical axis thereof.

5. The tow bar according to claim 4 wherein said first means comprises a hollow toroidal ring fitting into one end of said body and protruding into the interior thereof, said toroidal ring being disposed in the plane of the major elliptical axis of said body.

6. A tow bar comprising an elongate tubular body substantially elliptical in cross section, a hollow toroidal ring having a maximum diameter exceeding the length of the major elliptical axis of said body and a thickness equal substantially to the length of the minor elliptical axis of said body, said ring being seated in one end of said body in the plane of the major elliptical axis thereof and being joined thereto by a welded seam, a coupling member welded to the opposite end of said body, said cou pling member including means for effecting pivotal attachment of said body to a vehicle which is to be towed, said last named means defining a pivotal axis which is parallel to the major elliptical axis of said body.

7. A tow bar comprising a pair of mated telescoping tubular members each having a substantial elliptical cross section, means for locking said members in fixed telescopic relation to provide a rigid elongate body, a toroidal ring secured to one end of one of said members in the plane of the major elliptical axis thereof, a coupling member for pivotally engaging a vehicle to be towed secured to one end of the other of said members, said toroidal ring and said coupling member beingdisposed at opposite ends of said rigid body, said coupling member defining a pivotal axis which is parallel to the major elliptical axis of said body.

References Cited in the file of this patent UNITED STATES PATENTS 1,290,813 Weaver Jan. 7, 1919 1,434,512 Thoennes Nov. 7, 1922 1,517,238 Stresau Nov. 25, 1924 1,536,751 Barnes May 5, 1925 1,846,567 Murray Feb. 23, 1932 1,951,151 Hopkins Mar. 13, 1934 1,974,966 McClure Sept. 25, 1934 2,061,269 Coakley Nov. 17, 1936 2,174,922 Kuiper Oct. 3, 1939 2,179,439 Trow Nov. 7, 1939 2,433,631 Sherman Dec. 30, 1947 2,451,698 Swinehart Oct. 19, 1948 2,457,745 Suess Dec. 28, 1948 2,497,234 Mylie Feb. 14, 1950 2,518,816 Powers Aug. 15, 1950 FOREIGN PATENTS 856,738 Germany Nov. 24, 1952

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