US3908260A

US3908260A - Method of making a truck ladder

Info

Publication number: US3908260A
Application number: US518468A
Authority: US
Inventors: Charles M Loomis; Gerald M Loomis
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-10-12
Filing date: 1974-10-29
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

Two pairs of transversely-aligned longitudinally-spaced veebottomed notches are formed in the opposite edges of the midportion of an elongated flat sheet metal blank, the opposite edge portions of which are then bent perpendicular to the central portion thereof to form an elongated channel member. This channel member is then bent transversely along the center lines of each pair of notches to form a top step integral with two parallel side rails which are then interconnected at and above their lower ends by a pair of fixed channel steps secured thereto in vertically-spaced parallel relationship. A wider foldable step is pivotally mounted on the side rails below the top step and carries a pair of centrally-bored attachment pins which initially guide a drill in drilling pilot holes in the truck body side wall for subsequent enlargement to receive the attachment pins which then secure the ladder to the truck body.

Description

United States Patent 1191 Loomis et a1.

1 1 METHOD OF MAKING A TRUCK LADDER [52] US. Cl. 29/434; 29/464; 29/476;

1 13/1 16 I [51] Int. Cl. B23? 11/00 [58] Field of Search 29/476. 464. 155. 469,

[56] References Cited UNlTED STATES PATENTS 720.891 2/1903 Chamberlain et a1. 182/206 X 1.621.696 3/1927 Vernet 29/434 1.836.354 12/1931 Abrams. 2.1 19.500 5/1938 Quigan.. 2.331.709 10/1943 Mayne 2.502.228 3/1950 Miller 182/93 1 1 Sept. 30, 1975 Nystrom 182/93 X Primary Eraminer-Charlie T. Moon [57] ABSTRACT Two pairs of transversely-aligned longitudinallyspaced vee-bottomed notches are formed in the opposite edges of the mid-portion of an elongated flat sheet metal blank, the opposite edge portions of which are then bent perpendicular to the central portion thereof to form an elongated channel member. This channel member is then bent transversely along the center lines of each pair of notches to form a top step integral with two parallel side rails which are then interconnected at and above their lower ends by a pair of fixed channel steps secured thereto in verticallyspaced parallel relationship. A wider foldahle step is pivotally mounted on the side rails below the top step and carries a pair of centrally-bored attachment pins which initially guide a drill in drilling pilot holes in the truck body side wall for subsequent enlargement to receive the attachment pins which then secure the ladder to the truck body.

9 Claims. 10 Drawing Figures 1 I METHOD OF MAKING A TRUCK LADDER This is a division of our co-pending application, Ser. No. 405,826, filed Oct. 12, 1973, for Truck Ladder.

SUMMARY OF THE INVENTION This invention particularly resides in the conversion of an elongated channel member with vee-notched flanges into a ladder top step integral with parallel side rails which are thereafter interconnected by channel lower fixed steps and an upper tiltable wider step possessing centrally-bored attachment pins the bores of which serve as drill guides for drilling truck body pilot holes which are subsequently enlarged to receive these attachment pins.

In the drawings,

FIG. lis a'front elevation, upon a reduced scale, of a truck ladder, according to one form of the invention;

FIG. 2 is a right-hand side elevation of the ladder shown in FIG. 1, with the upper and wider step in its extended position;

FIG. 3 is a vertical section taken along the line 3 in FIG. 1;

FIG. 4 is an enlargedhorizontal section through one of the side rails taken along the line 4-4 in FIG. 1;

FIG. 5 is an enlarged vertical section, taken along the line s s in FIG. 1;

FIG. 6 is an enlarged top planview of the folding upper step of the ladder shown in FIG. I, removed from the ladder;

FIG. 7 is a left-hand side elevation of the step shown in FIG. 6; I

FIG. 8 is an enlarged horizontal section taken along the line 88 in FIG. 1;

FIG. 9 is an enlarged top plan view of one of the stationary steps; and

FIG. 10 is a top plan view upon a reduced scale of the elongated sheet metal blank from which the top and side rails of the ladder are produced by subsequent bending operations.

Referring to the drawings in detail, FIG. 1 shows a truck ladder, generally designated 10, according to one form of the invention, as consisting generally of an integral top and side rail unit 12 of flanged channel crosssection to which are connected lower fixed steps 14 and an upper swinging step 16 pivoted to internal channel reinforcements 18. The top and side rail unit 12, as its name indicates, is composed of vertically-elongated parallel side rails or stiles 20 joined integrally at the upper comers 22 to the top member 24, the whole being formed in a single piece as described more fully below. Thus, the top member 24 serves as a bridge or cross member connecting the side rails 20 at their upper ends.

Each side rail 20 and the top member 24 are of channel cross-section (FIGS. 4 and 5), each side rail 20 having an end wall 26 which interconnects the side walls 28. The side walls 28 at their free edges are provided with narrow flanges 30 directed toward one another and separated from each other by a gap 32. Similarly, the top member 24 is provided with a top wall 34which interconnects opposite side walls 36 and the latter at their free edges are provided with narrow flanges 38 also directed toward one another and separated from one another by a gap 40. The top member 24 (FIG. 5) is also provided, in its top wall 34, with spaced holes 42 having upwardly-projecting frusto-conical rims 44 for providing an anti-slip constructionjThe side rails 20 and top member 24 are joined to one another at their corners 22 and also along the

oblique ends

46 and 48 respectively cut at angles of 45 degrees and welded or otherwise firmly secured to one another at the locations46 and 48 (FIG. I).

- The side rails 20'are also joined to one another at their lower ends and at a location spaced above the lower ends by the" fixed steps 14. The latterare also of channel cross-section with top walls 50 (FIG. 9) which interconnect side walls 52 -(FIG.' 3) from the lower edges of which narrow flanges 54 project toward one another leaving a space or gap 56 therebetween. Each of the fixed steps 14 at the opposite ends of its top wall 50 is provided with end extensions 58-which project outward from thedotted'lines 60 through the gaps 32 and lower or '

upper notches

62 or 64 formed in the flanges '30'of the side rails 20 (FIG. 10) into the interiors 66 thereof, where they are welded or otherwise secured in place.

The dimensions of the

notches

62 and 64 are similar to those of the end extensions 58 of the fixed steps 14 in order to pass therethrough. Each of the fixed steps 14, like the top member 24, is provided with laterallyspaced holes 68 (FIG. 9) having frusto-conical upwardly-projecting rims 70 for anti-slip purposes.

Each elongated internal channel reinforcement 18 (FIG. 8) has an end wall or web 72 interconnecting opposite side walls 74 but, unlike the side rails 20, top member 24 and fixed steps '14, has only a single flange 76. The channel reinforcements 18 (FIGS. 1 and 3) extend from slightly above the upper fixed step 14 to a location above the swinging step 16. The swinging step 16 (FIGS. 6 and 7) has a horizontal plate portion punched at staggered intervals with holes 82 having frusto-conical anti-slip rims 84 and drilled near its rearward edges with holes 86 in which are mounted ladderattaching pins 88 with central drilling guide holes 87 therethrough for drilling pilot holes in the side rail or outer edge of the truck floor outside the sides or side boards of the truck bed. These pilot holes are then used to drill holes the size of the ladder-attaching pins 88 which are inserted therethrough and locked in place by cotter pins (not shown) through transverse holes 89 near the ends of the pins 88. Depending from the forward edge of the plate portion 80 is a narrow flange 90 (FIG. 7) while from its opposite ends rise end flanges 92. Each end flange 92 is drilled'(FIG. 8) near its inclined forward edge 94 with a hole 96 in which is mounted a headed pivot pin 98, the head 100 of which is welded or otherwise firmly secured to its respective end flange 92. The end walls or webs 72 of the reinforcements 18 are provided with coaxial holes 102 adapted to receive the opposite ends of a support rod 104 extending thereacross immediately behind the front flange 90 when the swinging step 16 is in its horizontal or operative position. The forward flanges 30 of the side rails 20 are provided with notches 106 (FIG. 10) aligned with the holes 102 to afford clearances for the adjacent ends of the rod 104. The end walls or webs 72 of .the reinforcements 18 are also provided with holes 108 adapted to be aligned with one another to receive the pivot pins 98 during assembly, as described

notches

64 and 106 are punched or otherwise formed extending inward from the opposite edges 112 of the blank 110. Partially V-shaped and partially rectangular or parallel notches 114 are also formed in the same manner in longitudinally-spaced relationship inward from the opposite edges 112 with their V-

shaped portions

46 and 48 at forty-five-degree angles to the edges 112 and at ninety-degree angles to one another. The rectangular

outer portions

116, 118 are formed simultaneously with the V-

shaped portions

46, 48, so that the outline of each notch 114 thus resembles the end view of an ordinary barn. Either at this time or previously, the holes 42 with their frusto-conical rims 44 are formed in the central section 120, which ultimately becomes the top member 24 of the ladder 10.

The blank 110 is then subjected to bending operations along longitudinal bending lines running between the corners of the end notches 62 to form the flanges 30 at right angles thereto in a direction away from the plane of the paper in the drawing. This is conveniently done by rolling operations in a conventional rolling mill, as is well understood by those skilled in the metalworking arts. The shallow channel member thus formed is subjected to a second and similar rolling operation at the depth of the inner vertices ofthe notches 114 along bending lines parallel to the previouslymentioned bending lines, thereby forming the side walls 28 of the channel member having the end wall 26 and flanged configuration shown in FIG. 4.

- The thus-formed flanged channel member is then subjected to transverse bending operations along bending lines extending between the vertices of the notches 114, whereupon the

side edges

46 and 48 come together as shown in FIG. 1 to form the integral top and 1 side rail unit 12 of flanged channel cross-section previotherwise secured in position.

, Meanwhile, as these bending operations proceed, the opposite ends of the support rod 104 are aligned with the holes 102 in the reinforcements 18 and the pivot pins 98 are aligned with their respective holes 108, so that, as the bending nears its end, the ends of the rod 104 enter their holes 102 while the pivot pins 98 enter their holes 108. At the same time, the upper fixed step 14 is also aligned with its notches 64 (FIG. in the flanges 30 of the side rails 20, so that as the bending .thereof near its end. the opposite ends 58 of the upper fixed step 14 enter the interiors 66 of the side rails so as to become seated therein. The lower fixed step 14 is then welded into place in the lower notches 62, and the ladder 10 becomes completely assembled as shown in FIG. 1.

Alternatively, the welding of one or both of the headed pivot pins 98 can be deferred until the ladder has otherwise been assembled as described above, after which the pivoted upper step 16 is moved into its proper position between the side rails, as one of the previously-welded pivot pins 98 is pushed into its respective hole 108 in the end wall 72 of its respective retainer 18, whereupon the loose remaining pivot pin 98 is pushed through the then-aligned

opposite holes

96 and 108 and welded to the adjacent end flange 92.

We claim:

l A method of making a multiple-step ladder adapted to be attached to a truck body, said method comprising forming from sheet metal an elongated paralleledged blank, forming two pairs of transversely-aligned veebottomed notches in the opposite edge portions of said blank, said pairs of notches being formed equidistant from the opposite ends of said blank at locations corresponding to the intended locations of the ends of the top step of the ladder, bending the thus-notched opposite edge portions of said blank perpendicular to the remainder thereof along parallel longitudinal bending lines through the centers of said notches to form a channel member having a central wall and parallel side walls,

bending said channel member along transverse bending lines through each pair of said transverselyaligned notches into a central top step member and a pair of parallel ladder side members perpendicular to said top step member and integral therewith,

preparing a plurality of lower step members with lengths corresponding substantially to the distance between said central walls of said opposite side members,

and securing the opposite end portions of said lower step members to said opposite side members within the channels thereof and in spaced parallel relationship to said top member.

2. A method of making a multiple-step ladder, according to claim 1, wherein said vee-bottomed notches have parallel outer edge portions, and wherein said bending of said opposite edge portions is performed on bending lines passing through the junctions of said veebottomed notch portions and said parallel edge portions.

3. A method of making a multiple-step ladder, according to claim 2, including the additional step of bending the outer longitudinal edge portions of said side walls toward one another into co-planar flanges with a gap therebetween.

4. A method of making a multiple-step ladder, ac-

cording to claim 1, including the additional step of fixedly securing said lower step members to said opposi-te side members.

5. A method of making a multiple-step ladder, according to claim 3, including the additional step of inserting the opposite ends of said lower step members through the gaps in their respective adjacent side members, and also through the parallel-edged outer portions of their respective adjacent notches.

6. 'A method of making a multiple-step ladder, according to claim 1, including the additional step of pivotally mounting an upper step member on said opposite side members for tilting motion between positions respectively co-planar with and perpendicular to said opposite side members.

7. A method of making a multiple-step ladder, according to claim 6, including the additional step of mounting truck body attachment elements upon said upper step member in projecting relationship therewith, said elements being adapted to be secured to the truck body.

8. A method of making a multiple-step ladder, according to claim 7, including the additional step of providing drill guide bores in said attachment elements cording to claim 1, including the additional step of forming said lower step members in channel configuration prior to securing said lower step members to said opposite side members.

Claims

1. A method of making a multiple-step ladder adapted to be attached to a truck body, said method comprising forming from sheet metal an elongated parallel-edged blank, forming two pairs of transversely-aligned vee-bottomed notches in the opposite edge portions of said blank, said pairs of notches being formed equidistant from the opposite ends of said blank at locations corresponding to the intended locations of the ends of the top step of the ladder, bending the thus-notched opposite edge portions of said blank perpendicular to the remainder thereof along parallel longitudinal bending lines through the centers of said notches to form a channel member having a central wall and parallel side walls, bending said channel member along transverse bending lines through each pair of said transversely-aligned notches into a central top step member and a pair of parallel ladder side members perpendicular to said top step member and integral therewith, preparing a plurality of lower step members with lengths corresponding substantially to the distance between said central walls of said opposite side members, and securing the opposite end portions of said lower step members to said opposite side members within the channels thereof and in spaced parallel relationship to said top member.

2. A method of making a multiple-step ladder, according to claim 1, wherein said vee-bottomed notches have parallel outer edge portions, and wherein said bending of said opposite edge portions is performed on bending lines passing through the junctions of said vee-bottomed notch portions and said parallel edge portions.

4. A method of making a multiple-step ladder, according to claim 1, including the additional step of fixedly securing said lower step members to said opposite side members.

6. A method of making a multiple-step ladder, according to claim 1, including the additional step of pivotally mounting an upper step member on said opposite side members for tilting motion between positions respectively co-planar with and perpendicular to said opposite side members.

8. A method of making a multiple-step ladder, according to claim 7, including the additional step of providing drill guide bores in said attachment elements adapted to precisely align a rotary drill while drilling pilot holes in the truck body for subsequent enlargement into fastener holes for ladder supporting fasteners.

9. A method of making a multiple-step ladder, according to claim 1, including the additional step of forming said lower step members in channel configuration prior to securing said lower step members to said opposite side members.