US3491394A - Dockboard - Google Patents

Description

Jan. 27, 1970 R, L. LE .YCLEAR DOCKBQARD Filed Aug. 22. 1967 INVENTOR ROBERT L. LeCLEAR BY ,II

ATTORNEYS.

United States Patent 3,491,394 DOCKBOARD Robert L. Le Clear, Albion, Mich., assignor to T & S Equipment Co., Albion, Mich., a corporation of Michigan Filed Aug. 22, 1967, Ser. No. 662,408 Int. Cl. E01d 15/12 U.S. Cl. 14--72 1 Claim ABSTRACT OF THE DISCLOSURE A dockboard for spanning the gap between a railroad car, and a loading dock, including a main platform, a support structure and locking means for preventing shifting of the dockboard while in use. The locking means includes a support plate which is reinforced by channel means and a pivotally mounted locking member containing downwardly and rearwardly spaced teeth to abut the edge of the loading dock. Pivoting and guide pin means are made integral with the locking member and movable with respect to the support plate while being held against disassociation therefrom.

This invention relates generally to material handling equipment, and specifically to portable ramp means of the type which can be efiiciently utilized for bridging a gap between two spaced apart surfaces.

It is common practice for goods to be shipped in railroad cars, and for some means to be utilized to unload the railroad cars onto an adjacent platform or dock. Most desirably, the unloading is effected by so-called fork-lift trucks. In most instances, if not all instances, When a railroad car is adjacent a fixed platform, there is a gap between the car and the platform so that a fork lift truck cannot drive into the car unless some ramp is provided. It is the type of ramp used for this purpose with which the present invention is most directly involved.

There have been prior suggestions as to the manner in which the space between a fixed platform and a given railroad car could be spanned so as to permit the railroad car to be unloaded by a fork-lift truck driving therein from the adjacent platform. The suggested prior arrangements virtually all incorporated a platform member. The mere use of a platform member, however, was not itself suflicient because such member, if not fixed in position, would be movable and shiftable depending upon the forces exerted thereon by the fork lift truck entering or leaving the car with or without a load. Therefore, some of the prior arrangements incorporated a locking mechanism.

The basic concept underlying the use of a locking mechanism was, in some way, to maintain the platform member which spanned the pace between the railroad car and the fixed platform in a given position. Where the railroad cars were not loaded with contents completely up to the door line, the platform member could rest slightly inside the railroad car and slightly over the fixed platform. However, with the advent of so-called high cube railroad cars, the doors are slidable outside of the main floor surface of the car so that the cars could be loaded completely up to the door line. Thus, in this new type of car which is now finding widespread use, there is no floor space immediately adjacent the door within the car on which to rest the platform.

There thus was a need for a portable platform arrangement or dockboard which could be positioned between a fixed platform or dock and a high cube car so as to permit the contents thereof to be unloaded conveniently by a wheeled means such as a fork-lift truck. One of the objects of the present invention is to satisfy this need, and in this regard, it is a specific object hereof to achieve Patented Jan. 27, 1970 "ice the desired result by utilizing the door slide arrangement as a partial support for the portable platform mechanism.

Of equal importance, if not greater importance, is the technique by which the portable platform member is to be locked in position. When a fork-lift truck is operating to load or unload a railroad car or like item, the forces exerted on the platform mechanism are not only vertical forces of weight, but also lateral forces depending upon turns, weight distribution, and the like. It is thus essential that the means for securing the portable platform member in position be capable of withstanding lateral forces and torsional forces, as well as the normal weight, without di torting in any way.

Prior locking arrangements have not been capable of withstanding the miscellaneous forces to which they are subjected in many instances. In all prior locking arrangements which prove satisfactory and of which present knowledge is available, the locking member or support therefor had some structural weaknes which prevented its efficient utilization under varying load conditions.

Thus, another object of the present invention is to overcome such problems and provide a portable platform member or dockboard with a locking means as a part thereof, which locking means positions the platform member or dockboard in desired location, and maintains the same in that location without distortion of the locking component, irrespective of the forces to which it is subjected.

Even more specifically in this regard, it is an object hereof to provide a locking arrangement incorporating a locking member and a support plate therefor, wherein the locking member is pivotally movable through a given are by virtue of its mounting on the support plate, and wherein the support plate, while contoured and shaped to permit the desired pivotal movement, is specifically reinforced by connecting means so as to prevent distortion thereof.

Consistent with the preferred embodiment of the invention, the dockboard provided hereby includes a main platform, a support structure, and locking means secured to the support structure, which locking means has a locking plate member and a support member, with the locking plate member being solid and merely having pins therein and with the support member providing the pivot as well as an arcuate slot for controlled movement, but additionally, wherein the support member is reinforced by channel means connecting the same to the support structure of the unit.

The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description. Such description refers to the annexed drawings presenting a preferred and illustrative embodiment of the invention. In the drawings:

FIGURE 1 is a perspective view of a dockboard in use in accordance with this invention;

FIGURE 2 is a side view of the locking means of this invention;

FIGURE 3 is a side view from the rear of the locking means of this invention; and

FIGURE 4 is a top plan view of one end of the dockboard of FIGURE 1, including the locking means according to this invention with parts in section.

Referring to the drawings, there is shown in FIGURE 1 thereof a dockboard for high cube railcars in accordance with the preferred embodiment of this invention generally designated 10, a railcar 11, and a loading platform 13 partially broken away. The dockboard 10 includes a main platform or ramp generally designated 12, lifting handles generally designated 14, side guard rails generally designated 16, a supporting structure generally designated 18 and the locking means generally designated 20.

' Attention is drawn to FIGURE 1 wherein loading dock 13 is 'depicted'broken away so as to better illustrate the overall construction of the dockboard 1h}. The front edge of the loading dock 13;,is understood to continue along ex tension line F adjacent to which locking means 20, as hereinafter described in morepdetail, iSEShOWIl.

The main platform 12 comprises a substantially planar top surface 50 mounted between the side guard rails 16 and upon the supporting framework -18 which includes end members 19, front member 21, a rear member 23 and cross bracing members (not. shown). The main platform 12 is either rectangular in shape or'flared, tapering inwardly at the ends toward the rear. 7

..The rear member 23 of the supporting framework 18 projects downwardly a sufiicient distance that it will rest on, and engage, the bottom door-slide flange of a high cube rail car 11 and the main platform 12 will rest flush with the fioor surface of the car. In a dockboard for conventional rail cars according to this invention the rear portion of the main platform 12 will rest directly on the car floor.

The lockingzmeans 20, shown in FIGURES 2 and 3, comprises a locking member 22, a support plate 24, a guide pin 26 and a pivot pin 28: The locking member 22 contains a plurality of teeth at its forward end, said teeth 30 being stepped downwardly and readwardly and being of sufficient size so that a selected one of said teeth 30 will abut the edge of the loading platform 13 according to the size of the gap 15 (FIGURE 1), thereby supporting the dockboard and insuring against unwanted movement. The support plate 24- is fixediy mounted, as by welding, to the frame 18 by channel pieces 34. Channel pieces 34 reinforce support plate 2 and prevent structural weaknesses from manifesting themselves therein. The locking member 22 is pivotally mounted on support piate 24 by means of pivot pin 28 located in the upper rear portion of the locking member 22 and the support plate 24. The pivot pin 28 is fixedly secured to the locking member 22, becoming an integral part thereof, and rotatably secured to the support plate 24. The support plate 24 also contains an arcuate siot 32 in which cooperating guide pin 26 slideably engages. Guide pin 26 is fixedly secured to, and therefor integrai with, locking member 22 and, along with the arcuate slot 32, defines the I limits of travel of locking member 22 when it pivots about pivot pin 28. Due to this unique integral construction, locking member 22 is free of structural weakness.

Referring to FIGURE 4 the locking means is shown in part of a flared dockboard in accordance with this invention. Guide pin 26 and pivot pin 28 are fixedly attached to locking member 22 at and 42 respectively. This is done by any suitable means such as welding. Guide pin 26 is secured in support plate 24 by any suitable means which will allow guide pin 26 to slide in the arcuate slot 32 but which will prevent removal of guide pin 26 such as by a washer 36 welded to guide pin 26. Similarly, pivot pin 28 is secured to the support plate 24 as by washer 38 welded to pivot pin 28 such that pivot pin 28 is free to rotate but may not be pulled loose. While a space is shown between attaching means 40, 42 and support plate 24 it is clear that such a space is sufliciently small that wobble does not occur, or it may be considered to represent a bearing surface.

Lifting handles 14 are mounted in tandem onto the main platform 12 in a known manner and remain in a vertical position when rotated across their center point. They are spaced such that the forks of a fork-lift truck will engage them in order to transport and position the dockboard. When the lifting handles 14 are rotated back across their center point they retract rearwardly, toward the car, into the grooves 52 so as not to interfere with loading or unloading operations. The lifting handles 14 can be manually retracted into the openings 52, or by contact with the first fork-lift truck or other vehicle to cross the dockboard. A finger-hole 54 is positioned in each of the openings 52 so that the lifting handles can be grasped and raised by hand. The lifting handles 14 are positioned about the center of the main platform 12 so as to maintain proper balance when handlingthe dockboard with a fork= lift truck.

While the main platform 12 is described without an additional lip member thereon it is toQbe understood that the same may be provided without departing from the spirit or scope of this invention.

Having considered in detail the construction of .the preferred embodiment of the inventive dockboard, attention is now drawn to the preferred mode of use. When the dockboard 10 is lifted by afork lift truck by means of lifting handles 14, the lockingamembers 22 drop to the lower limit of their travel as determined by arcuate slot 32 and the cooperating guide pin 26. Obviously, when the dockboard 10 is lowered into the proper position spanning the gap 15 between rail car 11 and loading dock 13, a corresponding one of the teeth 30 on each locking member 22 first engages and abuts the front edge F of loading dock 13. As the dockboard 10 further is lowered, the locking members 22, along with their pivot pins 28, pivot upwardly with respect to the support plates 24 and other members gvhich are fixed to support structure 18, When the dockboard 10 has finally been positioned the locking members 22 firmly abut the front edge F of the loading dock and effectively prevent unwanted movement. The fork-lift truck then disengage-s from the lifting handles 14 and proceeds to either load or unload freight from the car.

It is therefore clear that this invention provides a dockboard including a floor or platform means, a supporting frame means beneath the floor means, including a support means at opposite lateral sides of the floor means and a locking means. The locking means includes a support plate at each lateral side of the dockboard having a pivot pin accommodating opening therein and as shown in FIGURE 2, also having an arcuate slot having its center line determined by a radius from the center of the said opening. Latching members are provided in the form of plates 22 having radially spaced seats as at 30 for self-selective abutment with an edge of a gap to be spanned by the dockboard, see F, FIGURE 1. A pivot pin 28 extends perpendicularly inwards of one face of each latching member at a location spaced from the seats or teeth 30. A second pin 26 extends perpendicularly inwards from the same face of the latching members in spaced relation to the first pin and at a location determined by the radial distance between the center line of the arcuate slot and the center of the pivot pin accommodating opening in the adjacent support plate. Means are provided that rigidly secure the pins to the latching members to maintain the pins in parallel relation. Further, as shown, the pins are transversely and longitudinally dimensioned to be accommodated within and proiect through and beyond the openings and slots respectively, so as to provide a pivot bearing relation between each pin 28 and its associated opening and a guiding relation between each pin 26 and the associated slots 32. Means are rigidly secured to the ends of each pin inwardly of the support plate to prevent disassociation of said pins from the openings and slots respectively. Reinforcing means are provided that extend inwards of the support plates at least one opposite sides of the slots and which are rigidly secured to the support means to connect the support plates and associated latching members to the dockboard and to assist rigidifying the support plates to prevent warping thereof, a responsive to heavy lateral thrusts occasioned during extended use of such a dockboard.

Thus, it will be seen that a preferred embodiment has been particularly described consistent with the aforementioned objects of this invention. This embodiment is to be considered illustrative and in no way limiting.

What is claimed is:

1. A dockboard including a floor means, a supporting frame means beneath said floor means and including a support means at opposite lateral sides of said floor means, a locking means comprising a support plate having a pivot pin accommodating opening therein and also having an arcuate slot therein having its center line determined by a radius from the center of said opening, a latching member comprising a plate having radially spaced seats for self-selective abutment with an edge of a gap to be spanned by the dockboard, a pivot pin extending perpendicularly inward of one face of said latching member plate at a location spaced from said seats, a second pin extending perpendicularly inward of said one face of said latching member plate in spaced relation to said first pin and at a location determined by the radial distance between the center line of said arcuate slot and the center of said pivot pin accommodating opening, means rigidly securing said pins to said latching member plate to maintain said pins in parallel relation, said pins being transversely and longitudinally dimensioned to be accommodated within and project through and beyond said opening and slot respectively, so as to provide a pivot bearing relation between said first pin and said opening and a guiding relation between said second pin and said slot, means rigidly secured to the ends of said pins inwardly of said latching member plate to prevent disassociation of said pins from said opening and slot respectively, and reinforcing means extending inwards of said support plate at least on opposite sides of said slot and rigidly secured to one of said support means to connect said support plate and latching member plate to said dockboard and to assist in rigidifying said support plate to prevent warping thereof responsive to heavy lateral thrusts occasioned during extended use of such a dockboard.

References Cited UNITED STATES PATENTS 1,131,783 3/1915 Howard 1472 2,083,178 6/1937 Woodruff 14-72 2,337,138 12/1943 Van Berg 14-72 2,521,349 9/1950 Diamond 14-72 3,238,548 3/1966 Christensen 14-72 JACOB L. NACKENOFF, Primary Examiner

Images