US 3796410 A
A deflectable guiderail adapted for positioning at the end of a rack aisle to restrain handling equipment from damaging a rack upon such equipment entering or exiting the aisle.
Claims available in
Description (OCR text may contain errors)
I United States Patent 1 1 1111 3,796,410 Konstant I Mar. 12, 1974 [5 GUIDERAIL FOR STORAGE RACKS 1,921,653 8/1933 Boyer 293/74 1,452,875 4/1923 H831 256/1  Invent Amhm'y Mount 1,670,963 5/1928 Hart? 293/74 Prospect, 1,808,767 6/1931 D6G10f1a e! 211. 256/1 1,870,639 8/1932 Mueller 256/13.1 x  Asslgnee' Speedrack Skokle 2,236,175 3/1941 Hauck 256 1  Filed: June 22, 1972 2,776,116 1/1957 Brickman 256/131 [-21] 265229 Primary Examiner Dennis L. Taylor Attorney, Agent, or Firm-Fitch, Even, Tabin & 52 us. c1. 256/1, 256/13.1 Luedeka 1 ] Int. Cl. B6lf 9/00, E01f 9/00  Field of Search 256/], 13.1; 293/62, 63,
293/74, 75, 83, 69 R, 88; 267/139, 113, 116;  ABSTRACT 1 1 14/219; 61/43 A deflectable guiderail adapted for positioning at the end of a rack aisle to restrain handling equipment  Referen cit d from damaging a rack upon such equipment entering UNITED STATES PATENTS orex'tmg 3,710,524 1/1973 Seiz 256 131 x 10 Claims, 3 Drawing Figures Tq 1 56 45 11*1 1 1 1.3 1 1 31 2'3 23 I9 34 memmm 1 2 m4 BLT-86,410
GUIDERAIL FOR STORAGE RACKS The present invention relates to guiderails and is directed to guiderail assemblies which are positioned at the entrance to warehouse rack aisles.
Lift trucks are commonly employed to move goods in a warehouse. These trucks, often called order pickers, move in and out of the track aisles transporting items which are stored on the racks. The itemsare carried in front of the trucks on forks or booms which are an integral part of the trucks.
The rack aisles in which these trucks operate are usually narrow to make the maximum utilization of warehouse floor space. As a consequence, it is common for such equipment to strike the racks as the equipment moves into or out of the aisle. When such an accident occurs, the truck, the rack or both may be damaged.
It is therefore desirous to have guiderails or guardrails positioned at the entrances to these rack aisles which will restrain the handling equipment from striking the racks. For optimum efficiency, these guardrails should be capable of limited deflection movement, for if the handling equipment struck a rigid guardrail, the handling equipment could be damaged or the load, which the handling equipment may be carrying, couldbe jarred. Although these guardrails should allow for deflection, there should be a positive limit to the amount of deflection movement to stop the handling equipment prior to striking a rack if it has not yet altered its course. Further, these guardrails should possess an impact cushioning capability which will be effective in neutralizing impacts throughout a broad range of angles of incidence. As these guardrails are designed to deflect under an impact, they should also be constructed so as to return to their original position after the source of the impact has been removed, and the capabilities of the guardrail should permit repeated deflections to be sustained without losing its efficiency.
It is an object of this invention to provide an assembly for positioning at the entrance or exit to storage rack aisles which provides a deflectable guardrail.
It is another object of this invention to provide a guardrail assembly which protects a rack from impacts which may come from different directions of incidence.
It is another object of this invention to provide a resilient guardrail which becomes relatively rigid after a' predetermined amount of lateral movement.
These and other objects of the invention are more particularly set forth in the following detailed description and in the accompanying drawings, of which:
FIG. I is a plan view of a guardrail assembly formed in accordance with the present invention;
FIG. 2 is a side elevation view of the guardrail assembly of FIG. 1; and
FIG. 3 is stop motion plan view showing a pair of guardrail assemblies'as illustrated in FIG. 1 positioned at the entrance to a rack aisle with one assembly being depicted during the instant it is struck by a truck.
While the invention will be described in connection with a preferred embodiment, it will be understood that this is not intended to limit the invention to this particular embodiment.
The present invention is concerned with a guardrail assembly to protect the entrances and exits to storage rack aisles. A rack aisle is the space between two vertical storage racks, both of which are to be protected. A guardrail assembly is designed to be emplaced adjacent that corner of both the racks nearest the aisle entrance. Thus, these guardrail assemblies are deployed in pairs, a right hand guardrail assembly at the corner of one rack and a left hand" guardrail assembly at the corner of the other rack. The two assemblies are mirrorimages of each other, and only the left hand guardrail assembly is hereinafter described.
In the drawings there is illustrated a preferred embodiment of a guardrail assembly (hereinafter some times referred to as the assembly) denoted as 11 which possesses features of the present invention. Very generally, the assembly 11, comprises a base 13 and a guardrail 15; the base 13 cooperating with the guardrail 15 to mount and support the guardrail for limited swinging or deflection movement in a predetermined direction.
The base 13 is a flat rigid plate, formed from steel or the like and generally L-shaped in plan, having a major let 17 and a minor leg 19. The base 13 is adapted to be placed flat against the floow of a warehouse and may be formed from a single piece of material, or the major leg 17 and the minor leg 19 may be separate pieces that are joined by welding. One of the minor legs elongated vertical edges is denoted as the base front edge 21 for purposes of reference. The base 13 is drilled to provide five holes 23 which extend through the plate and are utilized with appropriate bolts for anchoring the base to the floor. These holes are spaced throughout the length of both legs of the base and are arranged to provide an effective transmission of shear and moment forces to floor of the warehouse.
Fixed to one corner of the upper surface of the base 13 is an upstanding bracket 27 which has four bolt holes 29 arranged in vertically aligned pairs. The bracket 27 is preferably made of a rigid metal plate, such as steel, and is welded tothe base 13. The bracket 27 is uniformly recessed a predetermined distance from the base front edge 21. Welded to the bracket 27 and the base 13 are two triangular supporting gussets 31 which are preferably made of a rigid metal, such a steel plate.
Extending from the left hand end of the support bracket 27 is an upstanding, movement-limiting abutment 33 which is welded to the base surface. The abutment 33 is positioned at an angle A to the front surface of bracket 27, which in thepreferred embodiment is about 15, and thus extends awayfrom the base front edge 21 toward the rear of the base at this angle A. The abutment 33 is made of a rigid metal plate, such as steel. The illustrated bracket 27 and the abutment 33 are formed from a single piece of plate stock which is bent to provide the desired angular relationship although separate pieces might be used. The single piece of plate stock used to form the bracket 27 and the abutment 33 is bent to gradually define the angle A between the two surfaces so as to provide an angular transition surface 35. The purpose of this transitional surface 35 will become apparent hereinafter. A reinforcing triangular gusset 34 is welded to the base 13 and the rear of the abutment wall 33.
A vertically aligned stiffener 36 extends along the upper. surface of the base 13 from the free end of the abutment 33 to the rearmost portion of the base 13. The bottom edge of the stiffener .36 is welded to both the base major 17 and minor 19 legs. The rearmost portion 37 of the stiffener 36 is bent generally at a angle and is generally flush with the rearmost vertical edge of the major leg 17. An upstanding generally V- shaped plate 38 is welded to the end of the stiffener 36 to form a quadrangular loop 39 in conjunction with the rear stiffener portion 37 and the stiffener 36, which loop 39 is located adjacent the rearmost portion of base leg 17. The stiffener 36 is preferably formed from a single piece of plate stock which is bent to form the bracket 27, the abutment 33 and the stiffener 36; however separate pieces may be used and welded together.
The guardrail 15 of the assembly is an upstanding plate of curb height which, in the preferred embodiment, is a leaf spring made of a tempered spring steel. While the guardrail 15 is preferably a resilient metal plate, a hinged rigid metal plate might be used, with the desired resilience being achieved by means of ancillary springs. in the preferred embodiment, the guardrail l5 is about 6 inches high.
When viewed from the top in FIG. 1, the guardrail 15 has in right to left sequence: a shank portion 41, an intermediate portion 43 and an arcuate portion 45. [n the shank portion 41 there are four bolt holes 47 which register with the bolt holes 29 in the bracket 27. The intermediate portion 43 is a straight line extension of the shank portion 41, and its rear surfaces in conjunction with the front surface of abutment 33 defines the aforementioned angle A of about 15. The arcuate portion 45, as viewed from the top, has a constant radius of curvature, the center of curvature being along a vertical line. v
The shank portion 41 of the guardrail 15 is rigidly attached to the bracket 27 by four plow bolts 51, or the like, and is elevated from the floor along its entire length a distance slightly in excess of the thickness of the base 13. The free terminus of the arcuate portion overlays the major leg 17 at a central location thereon.
The guardrail 15, mounted on the base 13 as described, is able to deflect, under force, rearwardly toward the center of the base until the intermediate portion comes in contact with the abutment 33. More specifically, an exterior force delivered to the front surface of guardrail 15 will primarily effect swinging, lateral movement of the intermediate portion 43. As this occurs, the angular relationship between the intermediate portion 43 and the abutment 33 will change, steadily causing angle A to approach zero as a limit. As the guardrail 15 is a spring, it resists the aforementioned movement with a constantly increasing internally created force. If the exterior force is sufficient to cause the intermediate portion 43 to contact the abutment wall 33, the intermediate portion 43 becomes a rigid curb preventing further lateral movement thereof. The intermediate portion 43 does not bend sharply at the juncture between the bracket 27 and the abutment 33 rather, it bends gradually, slowly coming into surface to surface contact with succeeding portions of the transition surface 35. This gradual bending of the guardrail l5 minimizes stress within the guardrail as it is bent. Should an external force be acting against the arcuate portion 45 after the intermediate portion 43 becomes rigid, the arcuate portion is still capable of spring resisted lateral deflection rearward.
After the external force has been removed, the guardrail 15 will return to its original position under the force provided by the inherent resiliency of the guardrail itself. In an alternate embodiment, a rigid post may be positioned adjacent the forward surface of the guardrail 15 in its unstressed position to insure the guardrail does not swing outward in a forward direction beyond its original position.
As the exterior force, in most instances, will be striking the guardrail 15 a substantial vertical distance above the floor, a moment force is created which tends to lift or rotate the front portion of the assembly upward. The stiffened major leg 17 of the base, which is rigidly anchored to the warehouse floor, provides an effective means to counteract this lifting force. The major leg 17 of the base 13 is spaced from the impact force and thus substantially increases the axis of rotation of the assembly 11 as well as providing a wider and more stable foundation for the assembly. Further, the L-shaped configuration of the base 13 provides this stabilization without obtruding into the area in which the racks themselves are located. The stiffener 36 provides increased strength to the minor leg 18 to minimize the possibility that the minor leg 19 would bend under the aforementioned forces.
In the preferred embodiment, the assembly 11 is positioned in the corner defined by two elongated rigid rack protecting curbs 53 and which are aligned perpendicular to each other (the racks which are supported by the columns 7l are not shown). The surface of the intermediate portion 43 of the guardrail 15 is positioned tangent to an imaginary extension of the vertical surface of curb 55. The arcuate portion 45 is tangent at one point to an imaginary extension of the vertical surface of curb 53. For maximum rigidity it is preferred that the assembly. 1 1 be rigidly connected to the curbs 53 and 55. In the preferred embodiment, one of the gussets 31 is welded to curb 55 and the stiffener portion 37 is welded to the curb 53.
When placed at the entrance or exit of a rack aisle, the assembly protects the racks from being struck by handling equipment. Any blow delivered to the guardrail 15 will cause the intermediate portion 43 to be deflected rearward with increasing resistance to movement until it is forced against the abutment wall 33 therebymaking that portion of the guardrail a rigid curb. During this deflection, the point of contact between the guardrail ]5 and a laterally moving external force creating agent (an order picker) is constantly changing. Simultaneously the angle of incidence of the external force is decreasing. As the angle of incidence decreases, the resultant force which deflects the spring is decreased. The combination of these factors will cause the order picker to be guided away from the guardrail 15 and into the rack aisle in all but the most severe instances. For an order picker moving generally toward the shank portion of the guardrail, the guiding effect is additionally effective because, as the point of contact moves towards the shank, the effective moment arm of the external force is decreased. In this re-' gard, an order picker approaching the assembly 11 from a location outside the rack aisle is restrained from striking the free terminus of the arcuate portion 45 and forcing it into the aisle as the loop 39 shields it from such an impact.
Shown in FIG. 3 is an illustrative order picker? 59 entering a rack aisle which is protected by left and right hand guardrail assemblies 11 and 61 respectively. The order picker" has a vertically movable boom 63 which extends well forward of the truck cab 65. Fittedaround the frame of the truck is a bumper 67. The bumper extends forward of the cab portion of the truck to envelop an imaginary vertical extension of the boom 63. Fitted at the four corners of the bumper are horizontally aligned rotatable guide wheels 69 which project outwardly from the bumper. These wheels are positioned to contact the guardrail before any other part of the truck has struck the protected rack (not shown).
The order picker 59 and the assembly 11 are shown in stop motion to show the relationship of the guardrail 15 to the wheel 69 when the order picker 59 has caused the guardrail 15 to be deflected rearward. The guide wheel 69 is in contact with the guardrail l5, and the forces created by the deflection of the guardrail l5 and the momentum of the order picker 59 are resolved at the point of contact between the wheel 69 and the guardrail 15. The ability of the wheel 69 to rotate aids in resolving these forces, and in the illustrated situation, the order picker would move in the direction R away from the edge of the rack (not shown) and its supporting colums 71.
Thus, the present invention provides an assembly for placement at the entrance or exit of a rack aisle which will protect the racks from impacts from divergent directions. An impact striking the guardrail 15 will cause it to be deflected rearward against resistance until a predetermined deflection has been achieved at which point the guardrail 15 becomes rigid. Upon removal of the impact load the guardrail will automatically return to its original position. The assembly is well suited for receiving and sustaining repeated impact loads from divergent directions with no decrease in efficiency.
While various of the features of the present invention are particularly set forth in the disclosure, it is not intended to limit the scope of the invention which is defined in the following claims.
What is claimed is:
l. A guardrail assembly adapted to be mounted on a horizontal supporting surface, said guardrail assembly comprising a base adapted to be fixed to the horizontal supporting surface having upstanding rigid bracket means mounted thereon, elongated horizontally extending leaf spring means of curb height supported at its one end by said upstanding bracket and adapted to permit horizontal swinging movement of the remainder thereof in a rearward direction, said leaf spring means being constructed to resist swinging movement in said rearward direction with increasing force, and
rigid abutment means fixedly connected to said base engageable by said leaf spring means intermediate its ends after limited swinging movement thereof in said rearward direcion so as to cause said intermediate portion of said leaf spring means to define a rigid curb when in engagement with said abutment.
2. A guardrail assembly in accordance with claim 1 wherein the opposite end portion of said leaf spring means is free and is curved in plan in said rearward direction.
3. A guardrail assembly in accordance with claim 2, wherein said bracket is in surface contact over a substantial distance with the rearward surface of said leaf spring means.
4. A guardrail assembly in accordance with claim 2 wherein means is included extending generally rearward from said abutmentand opposing displacement of said base upward from the'horizontal supporting surface.
5. A guardrail assembly in accordance with claim 4 wherein said displacement-opposing means includes a vertical plate portion rigidly attached to and extending rearward from said abutment.
6. A guardrail assembly in accordance with claim 5 wherein said vertical plate portion is located so as to block further deflection of said curved end portion of said leaf spring means after said end portion deflects a predetermined amount following engagement between said abutment and said intermediate portion.
7. A guardrail assembly adapted to be mounted on a horizontal supporting surface, said guardrail assembly comprising a base adapted to be fixed to the horizontal supporting surface having an upstanding rigid bracket mounted thereon,
an elongated horizontally extending leaf spring of curb height supported at its one end by said upstanding bracket, the opposite end portion of said leaf spring being free to allow horizontal swinging movement thereof in a rearward direction, and
rigid abutment means fixedly connected to said bracket means engageable by said leaf spring intermediate its ends after limited swinging movement thereof in said rearward direction so as to cause said intermediate portion of said leaf spring to act as a rigid curb when in engagement with said abutment.
8. A guardrail assembly in accordance with claim 7, wherein upstanding second abutment means is in cluded disposed generally adjacent the free end portion of said leaf spring and blocking such contact by a lift truck with said end portion that would deflect said leaf spring in a forward direction.
9. A guardrail assembly in accordance with claim 8 wherein a vertical stiffener portion rigidly attached to said abutment extending generally rearward therefrom opposes displacement of said base upward from the horizontal supporting surface.
10. A guardrail assembly in accordance with claim 9 wherein said vertical stiffener portion is located so as to block further deflection of said curved end portion of said leaf spring after said end portion deflects a predetermined amount following engagement between said abutment and said intermediate portion.