US1928158A - Ladder - Google Patents

Description

Sept. 26, J, Q RUSE LADDER Filed Dec. 26, 1930 'fail Patented sept. 26, 1933 UNITED STATES A c c i A1,928,158 PATE-Nr osi-"rcs LADDER, John C. Ruse, Hlartville, Ohio Application December 26, 1930 serial No'. 504,730 5 claims. (o1. 22e-L64) i This invention relates to ladders,` and it has for its object to provide improvements devices for leveling the `ladder or an uneven supporting surface. y

Of the accompanyingV drawing, Fig; 1 isa front elevation of a'stepladder provided with my im- Drovements.` c

Fig. 2 is a side elevation thereofjpartly broken away and in section.

Fig. 3 is a vertical section on the line,3`l-3"of Fig. 1.

Fig. 4 is a detail side elevation, partly broken away, showing the adjustment clamp for one-of the extensiblerearlegs. l

, Fig. 5 is a section on the line V5%-5V of Fig. 4.

` Fig. 6 isa side elevation, partly broken away and in section, of theY upper part of the stepladder, showing itin partly folded condition.

Fig. '7 is a partial `vertical section showing a modification;

Referring at firstv to Figs. 1 to 6, I have illustrated Va stepladder ofthe inverted V-type comprising a front ladder member 10 consisting` of side rails: 1l, a top step or platform 12 affixed to saidrailsA by brackets 13 on its under side,

` and a series of lower steps 14, together with a rear prop or leg structurecomprising legs 15 ,individually hinged at 16 tothe platformfbrackets .13

and connectedvby crossed; diagonal braces 17.

At the lower `end of .the ladder member `10 I provide an automatic self-'leveling and gripping foot structure of which the footlmember con sists of a stout metal strip, 18 semi-circularly curved in the form o f a bow andhaving its ends bent horizontally outward, and also turnedflatwise, to provide supporting feet 19. This foot strip slides circumferentially through a pair of U-shaped brackets 20 affixed to 4the respective side rails 11 near their lower ends and projecting inwardly therefrom, and through a rmiddle guide and clamping bracket '2l affixed to the lower side of the lowermost step 14, to vary its angular relation to the ladder, in the plane of the latter, and thereby reciprocally to alter the height of the feet 19. The foot strip 18 is formed with an outwardly-bent middle rib or corrugation 22 for the purpose of stiffening it.

The middle bracket 21 is formed asa metallic loop having a pair of upwardly- convergent legsV 23, 24 Vtogether `constitutingonemember of an "automatic clutch 'for frictional wedging engageof the ladder, I providea bowed plate spring 26` having one end or both'ends slidably fixed to the under side of the lower step 14 just inv front of a metal tie-rod 27 which connects the side rails 11, saidspring bearing against the reinforcing rib22.v The presence ofA a spring is not essential in all cases, since the foot member generally `vtends to release itself when'the engaging pressure is removed.,

It is further necessary Vto adjust the rearv feet inorder tojlevel the ladder with a fullfour-point contact on an uneven surface, and to alter the .those at the front vcan also vary in the new combination of front and rear leveling supports which ingA plate 33 loosely mounted in theupper end of sleeve. 31 has lone wing bearingaganst the end of the leg section 29 and the other wing nearing against the side `rail 28.A For setting orreleas-` ing said clamping plate there is provided a rockshaft' 34 journaled in bearing apertures in the front and rear Walls of the sleeve, said shaft forming the pivot of a leverwhich has a short warm or cam member 35 formed by cranking or p bending the shaft for coaction with said clamping plate 33, and a long` arm 36 provided with an inwardlybent handle portion 37 ,at its upper end 'for turning the rock-shaft and acting as a stop ,against the side rail 28 when the arm 85 is turned -to its upward position as `shown in the drawing, in which position it sets the clamping plate 33 in frictional locking engagement with the rail 28 to hold the 'leg section 29 at a fixed adjustment.

`When 'the clamp `is thus locked, the downward pressure of the ladder through the rail A28 is Vexerted inthe direction Vof the clamp-setting action of the lever and hence tends to increase the Ytightness of locking. To release the clamp,

`the lever is turned downwardly through approximately a half circle. y

Upona cross-rod 38, connecting the side rails 28 'of theprop member near their upper ends, Y,

is ,pivoted a shelf 39 for supporting pails or other objectswhen the stepladder is in use. The side bars 40 of said platform are carried forwardly to rest against the,` lower side of the topmost of the series of lowerA steps 14 when said ladder unfolded, and are .connected by a front cross-bar 41 which may be used asv ahandle to manipulate l the shelf VA pair of links l42, pivoted at their for- 7o `lengthsof the rear legs to accommodate extreme ward ends upon a tie-rod 43 connecting the side rails of the ladder member 10, and pivoted at their rear ends at 44 to the bars 40 between the rod 38 and the cross-bar 41, serve to form, with said bars 40, a toggle by which, through manipulation of the shelf 39 from either end, the prop member 15 may be either brought forward into its folded relation against the rear side of the ladder member 10 'or unfolded and held in fixed relation thereto when the ladder is set up for operation, the toggle members in the latter case passing over center to a position slightly indicated in Fig. 2.

In the operation of my invention, when the ladder member 10 is elevated to take its weight off the foot member 18, thelatter will be automaticallyreleased from gripping engagement with the .wedge legs 23` and 24 of the middle guide-bracket 21, and said member 18 may then be freely slid through the guides 20, 21 to vary the height of the feet 19 reciprocally with reference to said ladder member. Upward pressure on either of said feetwill automatically bring 'the' other one down to the supporting surface and thus 'adjust the foot member to said surface while the steps are held substantially horizontal. Hence 'this devicev accommodates itself automatically to any slopes or irregularities within Vits range, When downward pressure on the bracket 21 is restored, its wedges automatically lock against the edges of the member 18, by bodily sliding movement of the ladderand its brackets 20 and 21, relative to the member 18, in or longitudinally of the common plane `of the ladder and member 18, and clamp the latter against further movement.

The prop member 15 having been unfolded to the position shown in Fig. 2 by manipulation of the shelf 39 and its toggle, the other two feet of the ladderat the lower ends of the leg sections 29 may then be brought to'a bearing on the groundby causing the ladder to lean at the proper angle and adjusting the height of either'v or both of said leg sections if necessary, this adj ustment being quickly performed by loosening the clamps in the sleeve 3l, sliding the section 29 Y and resetting said clamp. While the adjustments at the front and the rear of the ladder are independently performed, the adjustable foot devices, having general characteristics as described, cooperate in the leveling lof the ladder in 'a shorter time and with less effort than has heretofore been required under similar conditions. Thus, in painting ya building, cleaning windows, etc., it is sometimes desired to straddle a hedgeor bushes with the V-type of stepladder herein Vi1- lustrated. The operator can automatically level his front portion with the self-adjusting footy member 18 and havingV done so, he can bring the prop member 15 into contact with the ground and adjustthe height'of either of the leg sections l39 if necessary. Often the sliding of one of said leg sections until it reaches the Vground after the other one has been placed on the ground,-

and clamping thereof, will be the only manual adjustment required.

My invention, embodied in a` stepladder subo stantially as described, provides for easy adjust,-

ment tov a 4-point bearing under almost any ground conditions' which may be encountered, as well as on stairways and other indoor or outdoor situations, and when leveled it is firmly held in the proper adjustment. After being used, the ladder can be quickly restored to its folded condition, in the desired length.

My improved self-adjusting and self-clamping out of lineas foot member may also be employed with other forms of ladders including the single or ordinary rung type, and in the modification illustrated in Fig. 7 I have represented such an application. In vthis case 11a indicates one of the side rails and 14a the lower rung step of a single ladder. 18 is a circumferentially-slidable, semi-circular foot member of the same construction as shown in Figs. 1, 2 and 3, having Vfeet 19 at the ends thereof and mounted in side guides 2O on the ladder rails. A modified middle guide 2la for the member 18 in this instance is formed by a pair of duplicate bracket plates 45 connected by bolts 46, 47 above and below the member 18. Said plates have intermediate upwardly-convergent, wedging portions 48 for gripping engagement with the edges of V'the strip 18 when bracket 21a is depressed by the weight of the ladder, and their upper ends are formed with clamping jaws 49 curved to conform to the ladder rung 14a for gripping the latter.

Various other modifications could be made within the scope of my invention, and I do not desire to limit said invention except as required by the claims hereof and the prior art.

I claim:

1. The combination, with a ladder, of a clutch "device, a bow-shaped member longitudinally slid- VVfor attaching it vto the ladder, a bow-shaped member having end feet and slidingly adjustable with reference to said brackets to vary the, relative elevation of said feet,A ,said brackets being bodily .slidable downwardly on said member, in the plane of the member, for clutch engagement, one of said brackets including a clutch' device'engaging "the member by such bodily sliding movement, and

clutch-releasing spring means associated with the middle bracket and bearing downwardly on the bow-shaped member.

3."Ih'e combination, with a ladder composed yoi? side 'rails and cross steps, of a pair of guides atth'elowe'r ends of Vsaidside rails, a clutch mem- 4 ber xedly attached 'to 'the lower step, and a vsubstantially semi-circular foot member sli'dable cir- 4cumferentially through said guides and adapted.

to'be gripped by the clutch member 'when subject 't'o the weight of the ladder.

4. The combination, with a ladder, of a pair of guide'sthereon, an intermediate bracket on-said ladder, having upwardly convergent wedging portions, and a substantially semi-circular foot mem- 'berslidable through said guides and bracket and provided with feet at its ends, said member hav- 'i'ng its edges gripped by said wedging portions when subject to the weight of the ladder.

, 5. A ladder including a side rail, a leg section longitudinally 'slidable thereon rand having' a clamping sleeve 'embracing said side rail, a friction clamp carried in said sleeve andfengaging the rail,'saidrclarnp comprising an L-shaped grip- 'pingplate loosely mounted inthe sleeve and having Wingsfbe'aring respeetively against a lateral "face of the Side rail andan end face of the leg section-and a lever 'pivoted on the sleeve for op- J OHN C. RUSE.

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