CO-MOLDED SHOE FOR A LADDER RAIL AND METHOD FOR FORMING SUCH SHOE

Abstract

A shoe for a rail of the ladder has a body with a bottom and a pair of sides in parallel relation to each other, and a tread co-molded to the bottom of the body. The bottom of the body can either be flat or generally U-shaped. The tread has a plurality of ribs formed on a surface thereof opposite the bottom of the body. The body is formed of a metallic material and the tread is formed of a polymeric material.

Claims

1. A shoe for a ladder rail, the shoe comprising: a body having a pair of side panels in parallel relation to each other and a bottom; and a tread co-molded to the bottom of said body.

2. The shoe of claim 1, said body having a generally U-shaped configuration, the bottom being curved and extending between said the pair of side panels, said tread conforming to a curvature of the bottom.

3. The shoe of claim 2, the bottom of said body having a plurality of slots formed therein, said tread being co-molded such that material of said tread extends into the plurality of slots.

4. The shoe of claim 3, said plurality of slots each having a generally T-shaped configuration with a bottom of the T-shaped configuration opening at the bottom of said body.

5. The shoe of claim 4, said plurality of slots being generally evenly spaced from each other at the bottom of said body.

6. The shoe of claim 2, the bottom of said body having a smooth curved and uninterrupted surface, the bottom having a first slot formed inwardly adjacent to one of said pair of side panels and a second slot formed inwardly adjacent to another of said pair of side panels, said tread having portions filling the first and second slots.

7. The shoe of claim 1, said tread having a plurality of ribs formed on a surface thereof opposite the bottom of said body.

8. The shoe of claim 7, each of said plurality of ribs extending across a width of said tread.

9. The shoe of claim 1, said tread being affixed to the bottom of said body without fasteners.

10. The shoe of claim 1, the bottom of said body being flat, said pair of sides extending upwardly from opposite sides of said bottom, said tread having an upper flat surface molded to the bottom of said body.

11. The shoe of claim 10, the bottom of said body having a channel formed therein, said tread being received in said channel.

12. The shoe of claim 11, said channel being defined by flanges extending downwardly from opposite sides of the bottom of said body.

13. The shoe of claim 10, said tread having a plurality of ribs formed on a surface thereof opposite the bottom of said body.

14. The shoe of claim 13, said plurality of ribs being evenly spaced from each other and extending transverse to a longitudinal axis of said tread.

15. The shoe of claim 10, the bottom of said body having a plurality of channels formed therein, said tread having material extending into the channels.

16. The shoe claim 1, said body being of a metallic material, said tread being of a polymeric material.

17. A method for forming a shoe for a rail of a ladder, the method comprising: forming a body having a pair of sides extending in parallel relation to each other and a bottom extending between the pair of sides; placing the body into a mold; flowing a polymeric material into the mold; and pressurizing the polymeric material in the mold so as to co-mold the polymeric material onto the bottom of the body so as to form a tread that is secured to the bottom of the body without fasteners.

18. The method of claim 17, the step of forming comprising: forming slots of the body at or adjacent to the bottom of the body, the step of pressurizing comprising: flowing the pressurized polymeric material into the formed slots.

19. The method of claim 17, the mold having channels formed on a wall thereof, the step of pressurizing comprising: flowing the polymeric material under pressure into the channel so as to form ribs at the bottom of the tread.

20. The method of claim 17, further comprising: removing the body with the tread affixed thereto from the mold.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0037] FIG. 1 is a bottom perspective view of a ladder shoe of one embodiment of the prior art.

[0038] FIG. 2 is an upper perspective view of the ladder shoe of the prior art of FIG. 1.

[0039] FIG. 3 is a perspective view of an alternative embodiment of the ladder shoe of the prior art.

[0040] FIG. 4 is a side elevational view of a ladder shoe in accordance with a first embodiment of the present invention.

[0041] FIG. 5 is a perspective view of a ladder shoe in accordance with a second embodiment of the present invention.

[0042] FIG. 6 is a perspective view of a third embodiment of the ladder shoe of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0043] Referring to FIG. 1, there is shown the ladder shoe 70 in accordance with a first embodiment the present invention. The ladder shoe 70 includes a body 72 having a pair of side panels 74 and 76. Side panels 74 and 76 extend in parallel relation to each other. The body 72 also has a bottom 78 that extends between the pair of side panels 74 and 76. A tread 78 is affixed to the bottom 78 of the body 72.

[0044] In the first embodiment shown in FIG. 4, the body 72 has a generally U-shaped configuration. The bottom 78 is curved and extends between the pair of side panels 74 and 76. The tread 80 has a curvature conforming to a curvature of the bottom 78. The bottom 78 of the body 72 has a plurality of slots 82 formed therein. The tread is co-molded such that the material of the tread extends into the plurality of slots 82. In this embodiment of the present invention, the plurality of slots 82 each have a generally T-shaped configuration such that a bottom of the T-shaped configuration opens to the bottom surface 84 of the bottom 78 of the body 72. The plurality of slots 82 are generally evenly spaced from each other at the bottom 78 of the body 72.

[0045] The tread 80 has a plurality of ribs 86 formed on a surface thereof opposite to the bottom 78 of the body 72. Each of the plurality of ribs 86 extends across a width of the tread 80. It can be seen that the tread 80 is affixed to the bottom 78 of the body 72 without fasteners. In the present invention, the body 72 is formed of a metallic material and the tread 80 is formed of a polymeric material.

[0046] FIG. 5 shows an alternative embodiment of the ladder shoe 90 in accordance with the present invention. As with the previous embodiment, the ladder shoe 90 includes a body 92 having side panels 94 and 96 extending in parallel relation to each other. The body 92 also has a bottom 98 extending between the pair of side panels 94 and 96. A tread 100 is affixed to the bottom 98 of the body 92.

[0047] It can be seen in FIG. 5 that the bottom 98 of the ladder shoe 90 has a smooth curved and uninterrupted surface. A first slot 102 is formed inwardly adjacent to the side panel 94 and a second slot 104 formed at a bottom of the second side panel 96. The tread 100 has portion filling each of the slots 102 and 104. Once again, the tread 100 is co-molded to the bottom 98 of the body 92. The tread 100 has a plurality of ribs 106 formed of a surface thereof opposite to the bottom 98 of the body 92. Each of the plurality of ribs 106 extends across a width of the tread 100. Once again, the tread 100 is affixed to the bottom 98 without fasteners.

[0048] FIG. 6 is shows a further embodiment of the ladder shoe 110 of the present invention. The ladder shoe 110 includes a body 112 having a pair of side panels 114 and 116 that extend in parallel relationship to each other. The body 112 includes a bottom 118 that extends between the pair of side panels 114 and 116. The bottom 118 is flat. The pair of side panels 114 and 116 extend upwardly from opposite sides of the bottom 118. The tread 120 has an upper flat surface affixed to the bottom 118 of the body 112.

[0049] In FIG. 6, it can be seen that the bottom 118 has a channel 122 formed therein. The tread 120 is received within the channel. This channel 122 is defined by flanges extending outwardly from opposite sides of the bottom 118 of the body 112. The tread 120 has a plurality of ribs 124 formed on a surface thereof opposite to the bottom 118 of the body 112. The plurality of ribs 124 are evenly spaced from each other and extend transverse to a longitudinal axis of the tread 120. The bottom 118 also includes a plurality of channels 126 that open at the bottom of the body 112. The tread has material extending into these channels 126. Once again, the body 112 is formed of a metallic material and the tread 120 is formed of a polymeric material.

[0050] The process of the present invention, for each of the above-stated embodiments, includes forming the body, placing the body into a mold, flowing a polymeric material (as used for the tread) into the mold, and pressurizing the polymeric material in the mold so as to co-mold the polymeric material onto the bottom of the body so as to form a tread that is secured to the bottom of the body without fasteners. Slots can be formed in the body of the bottom of the body and then the pressurized polymer is flowed into these formed slots. The mold can have channels formed in the wall thereof. The polymeric material is flowed into the mold under pressure and into the channel so as to form ribs at the bottom of the tread. Following the formation of the shoe, the shoe is removed, with the tread affixed thereto, from the mold.

[0051] In the present invention, the tread is secured to the shoe without fasteners. This eliminates the extensive processes used in the mechanical fastening of the shoe to the body. The co-molding of the tread to the body assures that the tread is strongly secured to the shoe. Furthermore, the co-molding of the tread to the body without the use of fasteners avoids the possibility of the fasteners extending beyond the ribs of the tread and ultimately causing a marring of an underlying surface. The process of the present invention greatly reduces the costs associated with the manufacturing of the shoe and greatly expedites the manufacturing of the shoe. Additionally, the aesthetic appearance of the shoe is improved since mechanical fasteners are not exposed at the tread of the shoe.

[0052] The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction or in the steps of the described method can be made is the scope of the present invention without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.