US3691576A - Span structure - Google Patents

Abstract

The invention relates to a novel span structure as for ramps and bridges having a series of crossbeam members secured to an assembly of side elements which comprise an upper hollow longitudinal member capable of withstanding compression forces, a lower longitudinal runner element capable of withstanding tension forces, a vertical side element between the hollow member and the lower element, and a vertical stiffener element between the crossbeam and the lower element. The structure has uniform longitudinal flex and the side elements provide a column effect.

Description

United States Patent Miles et al.

[54] SPAN STRUCTURE [72] Inventors: Ray P. Miles, 8575 W. Melody Lane, Macedonia, Ohio 44056; Andrew F. Szucs, 4479 W. 226 St., Cleveland, Ohio 44126 22 Filed: Dec. 18, 1970 [21] Appl. No.: 99,368

Related US. Application Data [63] Continuation-in-part of Ser. No. 763,175, Sept.

27, 1968, Pat. No. 3,548,433.

[52] [1.8. CI. ..14/72, 14/73, 52/174 [51] Int. Cl ..F01d 15/12 [58] Field of Search ..14/17, 1, 73, 72,13,14; 52/174, 667, 664, 669

[56] References Cited UNITED STATES PATENTS 795,899 8/1905 Cunningham ..52/174 527,430 10/1894 Knights ..52/174 a 1 1 Sept. 19, 1972 60,205 12/ 1 866 Leopold ..14/17 2,390,194 12/1945 Tarof ..l4/73 X 2,336,622 12/1943 Le Tourneau 14/1 7 2,246,766 6/ 1941 Tarof ..14/73 X 2,266,543 12/1941 Francis ..l4/72 UX Primary Examiner-Jacob L. Nackenoff AttorneyMi1len, Raptes & White [5 7] ABSTRACT The invention relates to a novel span structure as for ramps and bridges having a series of crossbeam members secured to an assembly of side elements which comprise an upper hollow longitudinal member capable of withstanding compression forces, a lower longitudinal runner element capable of withstanding tension forces, a vertical side element between the hollow member andthe lower element, and a vertical stiffener element between the crossbeamand the lower element. The structure has uniform longitudinal flex and the side elements provide a column effect.

6 Claims, 5 Drawing; Figures PATENTEI] SEP l 9 I972 SHEET 1 UP 2 INVENTORS RAY P. MILES ANDREW E. sz cs BY 1 $12 ATTORNEYS PATENTEDSEP 19 I972 3.691. 576

sum am 2 This application is a continuation-impart of copending U.S. Pat. application, Ser. No. 763,175, filed Sept. 27, 1968, which issued as US. Pat. No. 3,548,433 on Dec. 22, 1970.

This invention relates to a novel structure adapted to span a distance between two points. More particularly, the invention relates to a novel structure for mobile yard rampsand the like.

Mobile yard ramp structures are adapted to facilitate loading and unloading of mobile carriers, such as rail road freight cars and the like, and also other types of carriers such as airplanes and large trucks. In general, the invention provides a structure which facilitates the loading and unloading of such vehicles and is further characterized by its ability to be easily towed along highways and easily maneuvered in the areas of use. In particular, the invention provides ramp structures which are capable of with standing heavy loads, such as loaded forklift trucks which travel up and down the ramp when in use.

Although, the novel structure of this invention will hereinafter be described with reference to a mobile yard ramp, the invention is not limited thereto. Thus, the novel structure is capable of being used to construct bridges and the like.

In general, amobile yard ramp fabricated according to this invention includes the novel ramp structure, a pair of wheels positioned approximately midway of the length of the ramp. A third wheel is provided longitudinally of the ramp and imparts stability to the ramp. When exact positioning of the ramp has been accomplished, the third wheel is withdrawn and that end of the ramp nearest the wheel comes into engagement with the ground.

In the copending application referred to heretofore, a motorized yard ramp is described and claimed, which is provided with power means for self-locomotion and is dirigible. The motorized ramp is provided with controls to enable an operator to move the ramp into a work position. The ramp is also provided with a retractable pair of wheels for limited vertical adjustment of the ramp. Although the ramp structure of this invention can be used with the motorized yard ramp, it is not limited thereto, and can be used to construct a yard ramp having no power locomotion means, as well as other types of ramp structures, bridges, and the like. A variety of advantages will become apparent to those skilled in the art from a consideration of the following.

In the drawings:

FIG. 1 is a plan view of a mobile yard ramp and illustrates, by the phantom lines, the maneuverability of the ramp;

FIG. 2 is a side elevational view of the mobile yard ramp of FIG. 1 with its pair of wheels and trailing third wheel, all in the lowermost position for ease in transporting the ramp, as by towing;

FIG. 3 is a fragmentary view of the elements involved in the basic construction of the structure of the ramp;

FIG. 4 is a fragmentary top elevation of the mobile yard ramp showing details of the structure of the ramp;

FIG. 5 is a section taken along 5-5 of FIG. 4.

Referring now to the drawings, a mobile yard ramp constructed in accordance with this invention is defined by a generally rectangular and elongated ramp having sheet metal surface end portions 10. The sides of the ramp are denoted by the numeral 12 and upper rim portion 14 extend generally throughout the length of the ramp. Numeral l6 denotes a grating strip having serrated edges, the strips mounted together to define a main surface portion 18 of the ramp having extremely high friction qualities. This enables high traction between the ramp and any loading or unloading vehicle travelling thereon. The grating members 16 may be held in parallel relationship by transversely extending rod members 22, as shown at FIG. 3.

The ramp structure is constructed as shown in FIGS. 3 and 4. A series of crossbeam members 20 are welded to an assembly of longitudinal side web elements 12 and upper elements 14 at spaced longitudinal portions. The lower portions of side elements 12 are secured to longitudinal runner elements 24 and to vertical stiffener elements 26. The elements .26 are also secured to the underside of transverse beam members 20 and to runner elements 24.

The elements 12-, 14, 24, and 26 secured together, as by welding, provide a structure for the ramp which has a column effect. A load on grating 16 with resultant bending of beams 20 will cause no twisting or tipping of the column and beams 20 will remain substantially perpendicular to the column. There will be uniform longitudinal flex along the entire column from one end to the other under load with element 14 taking the compression forces and element 24 taking the tension forces.

Element 14 is a hollow member of generally rectangular cross section as shown or any other suitable geometric cross section known in. the art, as for example, tubular, capable of withstanding the bending forces when a load is applied to the grating.

The elements 12, 14, 20, 24, and 26, as stated, are suitably welded together to produce a unitized construction. Alternatively, other suitable fastening means known in the art can be used, such as rivets. There is no strain on the fastening means since all the welds subject to the greatest stresses are in compression under load conditions.

The numeral 30 denotes eitherone of two wheels as in the form of conventional tires which are mounted on the ends of axle 32. The numeral 34 denotes in general a prime mover or power source, such as a gasoline engine, and is mounted generally midway of one of the transverse beam elements 20. The power source 34, through suitable shafts and gearing, is for the purpose of moving the ramp into a work position and/or supplying power to hydraulic means for vertical adjustment of the ramp as more fully described in the copending parent application, Ser. No. 763,l75, referred to heretofore.

The numeral denotes a third wheel positioned an appreciable distance from the wheel 30 and suitably mounted on the underside of the :ramp and preferablymidway thereof. The third wheel is adapted to be positioned in a solid extended position as shown in FIG. 2 when the ramp is being moved, or in a retracted position when the ramp is in a work position with one end resting on the ground. The wheel is manually operable to either position by a handle 116.

What is claimed is:

l. A span structure useable as a bridge or ramp comprising a series of crossbeam members each end of which is secured perpendicularly to an assembly of longitudinal side elements, said elements comprising:

a. an upper hollow longitudinal element capable of withstanding compression forces and functioning as a curb element,

b. a lower longitudinal element capable of withstanding tension forces,

0. a vertical web element connecting said upper and lower elements,

d. a vertical stiffener element connected to said web element, to said lower element, and to the underside of said crossbeam member,

e. said crossbeam member end portion connected to said web element and to said hollow longitudinal element. 2. The span structure of claim 1 wherein said series of crossbeams have an overlay of grating strip.

3. The span structure of claim 1 wherein said upper element has a substantially rectangular cross-section.

4. The span structure of claim 1 wherein said upper element has a substantially tubular cross-section.

5. The span structure of claim 1 wherein said vertical stiffener element is perpendicular to said web element.

6. The span structure of claim 1 wherein said hollow longitudinal element is connected to the upperside of said crossbeam member.

Claims (6)

1. A span structure useable as a bridge or ramp comprising a series of crossbeam members each end of which is secured perpendicularly to an assembly of longitudinal side elements, said elements comprising: a. an upper hollow longitudinal element capable of withStanding compression forces and functioning as a curb element, b. a lower longitudinal element capable of withstanding tension forces, c. a vertical web element connecting said upper and lower elements, d. a vertical stiffener element connected to said web element, to said lower element, and to the underside of said crossbeam member, e. said crossbeam member end portion connected to said web element and to said hollow longitudinal element.

2. The span structure of claim 1 wherein said series of crossbeams have an overlay of grating strip.

3. The span structure of claim 1 wherein said upper element has a substantially rectangular cross-section.

4. The span structure of claim 1 wherein said upper element has a substantially tubular cross-section.

5. The span structure of claim 1 wherein said vertical stiffener element is perpendicular to said web element.

6. The span structure of claim 1 wherein said hollow longitudinal element is connected to the upperside of said crossbeam member.

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