US2205869A - Extension leg - Google Patents

Description

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J. G. WAKEMAN 2,25,869

EXTENS ION LEG Filed June 29, 1939 2 Sheets-Sheet 2 Z5 S11/vanto@ IZMz/eman.

Patented `lune 25, 194@ UTED STATES FATENT OFFICE 7 Claims.

This invention relates to certain new and useful improvements in extension legs.

The primary object of the invention is to provide an extension leg or leveling device especially designed for use with or attachment tol ladders, the construction thereof being such that the same is capable of use with articles of furniture of diiierent types,` such as tables and tripods or other supporting elements.

A further object of the invention is to provide an extension attachment for the legs of a ladder that are easily and quickly adjustable for changing the relative length of the side rails or legs of a ladder so that the same may be positioned in a true upright position irrespective of the unevenness of the ground or other support upon which the ladder is placed.

With the above and other objects in View that will become apparent as the nature of the invention is better understood, the same consists in the novel form, combinations and arrangement of parts hereinafter more fully described, shown in the accompanying drawings and claimed.

In the drawings:

Figure 1 is a fragmentary front view of a -ladder equipped with the extension legs, one of said legs being lowered for the support of the ladder in a vertical position;

Figure 2 is a fragmentary vertical cross-sectional view taken on line 2-2 of Figure 1, showing the extension legs secured to the inner side of the side rail of the ladder;`

Figure 3 is an enlarged inner side view of the side rail of the ladder showing a part of the extension leg rigidly secured to the side rail of the ladder;

Figure 4 is a cross-sectional view taken on line 4-fl of Figure 3;

Figure 5 is a vertical longitudinal sectional view taken on line 5-5 of Figure l, showing the movable part of the extension leg wedgingly engaged with the stationary part of the extension leg that is secured to the side rail of the ladder;

Figure 6 is a fragmentary longitudinal sectional view taken on line 6 6 of Figure 2;

Figure 7 is a longitudinal sectional view, similar to Figure 5 with the cover plate of the wedge devices removed and with the latter positioned to permit extensible movement of the extension legs;

Figure 8 is a cross-sectional view taken on line 8-8 of Figure 2; and

Figure 9 is a longitudinal sectional view of the tensioned roller operating pin equipped with a lubricating wick.

Referring more in detail to the accompanying drawings, thereference character lli designates the side rails of a ladder connected in the usual manner by the cross steps or rungs il, an extension leg designated in general by the reference character i2 being attached to the inner face or side of the lower end of each side rail I0.

Each extension leg is formed of two parts designated in general by the reference characters i3 and lf3 respectively, the part i3 being rigidly secured to a rail i8 of the ladder tvhile the part ifi is slidably associated with the part i3. The part l 3 of the extension leg as shown more clearly in Figures 3, 4 and 8, comprises an elongated plate l5 of the same width as the rail lil of the ladder and is secured to the inner face of the rail by means of screws i6 having their heads flush with the upper face of the plate l5, each longitudinal side edge of the plate l5 is turned inwardly as shown in Figures 4 and 8 to provide a guide channel l l with which the slidable part M of the extension leg is associated in a manner presently to be described. A longitudinally extending rib i8 perpendicularly rises from the base plate i5 for purposes presently to appear.

The movable part lli of the extension leg l2 cooperates with the plate l5 to form a casing or housing and includes an elongated outer wall I9 having longitudinal side walls 28 extending at right angles thereto, the free edge of each side wall 20 being bent outwardly at right angles to provide side edge flanges 2i slidable in the guide channels Il as shown in Figure 8. A longitudinally extending rib22 is carried by the inner face of the outer wall i9 and constitutes a brace or support for the rib I 8 carried by the stationary plate i5. The cross wall 23 is carried by the upper end of the wall i9 between the side walls 20 and has an opening 24 therein for the passage of the rib I8 as shown in Figures 5 and 7. A laterally directed foot 25 is carried by the lower end of the extension leg part Ml and underlies the side rail ill of the ladder, the same being reinforced by the angle brace 26 shown in Figures 6 and 7. For limiting extensible movement of the leg part it relative to the leg part I3, a headed screw 2l is driven through the plate l5 of the stationary leg part into the side rail I0 of the ladder with the head thereof projecting above the surface of the plate i5, said screw 2l' being located in proximity of the transverse median line of the plate l5, or elsewhere if desired and disposed for engagement by the cross wall 23 of the slidable part i4 of the extension leg to limit extensible movement of the latter relative to the stationary part I3. An opening 28 is provided in the outer wall I9 of the slidable part I4 of the extensible leg to facilitate the positioning of the top screw 2': after the two parts I3 and I4 are assembled.

Spring pressed wedge devices cooperating with the rib I8 of the stationary plate together with a manually operated release therefor are carried by the slidable section lil of the extension leg and as shown more clearly in Figures to 7 there is provided` a pair of longitudinally spaced wedge blocks 29 and Sil, each having an inclined wedge face 3l respectively inclining upwardly and downwardly away from the rib 22 carried by the wall I9. carried by the upper and lower ends respectively of the wedge blocks 29 and 3i) and is directed tof ward and terminates in spaced relation to the rib 22. A pin 33 slidably extends through each arm 3d into the angle area of the wedge block afforded by the wedge face il and the adjacent side of the arm 32, each pin 33 carrying a disk head 34 outwardly of the arm 32 that is normally held in engagement with said arm by means of an associated coil spring 35 engaged at one end with said disk head while the other end of the coil spring is engaged with an abutment 3S anchored to the inner face of the outer wall. I9. A cylinder or roller il is freely mounted in each triangular area bordered by the inclined face 3l of the wedge block and the adjacent wall of the arm and being engaged by the inner end of the tensioned pin 33 is influenced in a direction toward the rib 22. it will be observed that the rollers 3l engaged by the tensioned pins 33 and movable over the inclined faces Si of the wedge blocks 29 and Sil act in opposite directions and each of said wedge rollers 3l is rendered inoperable by a manually operated device.

As shown more clearly in Figures 6 and 7, a slide rod 38 is mounted within the wall It in proximity or the .rib 22 and the opposite ends thereof are disposed for reception in the triangular areas that house the wedge cylinders 3l, the rod 38 being slidable to cause the ends thereof to selectively engage the wedge cylinders for rendering them inoperative. As shown in Figure 6, the outer wall i9 of the extensible leg section i4 is provided with a longitudinal slot for the passage of the threaded shank it that is engaged with the slide rod, the threaded shank di? being carried by a slide rod operating button il positioned at the outer side of the wall IQ. A cover plate l2 overlies the slide rod f 38 and is anchored to the wedge blocks Ed and 3G by means of screws I3 that thread into openings di in the wedge blocks 29 and 3B. A longitudinally extending flange l5 is carried by one edge of the cover plate ft2 and cooperates with portions of the wedge blocks 29 and 3@ for guiding the slide rod 38 in its movements.

When the two parts or the extensible leg are assembled as shown in Figures l and 2 and fragmentarily assembled as shown in Figures 5 and 7, and it being desired to lower the extension part it relative to 'the stationary leg part I3 as shown in Figure l, the operating button for the slide rod 35i is lowered in the slot Si) which causes the lower end oi the rod 3E to engage the wedge roll-er :il associated with the lower wedge block Sil against the tension of the spring 35 associated therewith, the lower wedge roller 3l being freed o frictional binding engagement with the rib I8 carried b y the stationary plate I5 while the wedge roller 3l associated with A laterally directed arm 32 is the upper wedge block 29 will roll upwardly on the outwardly directed inclined wedge face 3l of the upper wedge block 29 to permit the extensible parts I@ of the leg to be lowered. When pressure on the operating button is released, the spring pressed pins 33 then move both wedge rollers 3l along the inclined widge faces 3l of the wedge blocks 29 and 30 into binding engagement with the stationary rib I8 so that the extensible leg section or part Ill is then rigidly held against movement in either direction. When it is desired to retract the extensible leg part Ill to the position shown at the left hand side of Figure 1, the operating operator button lll is moved upwardly in the casing slot 39 to position the wedge roller 3l associated with the upper wedge block 2Q at the upper end of the inclined wedge face the extensible leg section Iii will cause the wedge roller 39 associated with the lower wedge block 3i) to move downwardly over the inclined wedge face EI for disengagement from the stationary rib I8. l

The pin 33 as shown in detail in Figure 9'is or tubular construction and houses a lubricated wick i3d that supplies oil to the rollers 3l to prevent rust and wear on the rollers and to facilitate easy operation of the parts.

From the above detailed description of the device, it is believed that the construction and operation thereof will at once be apparent and while there is herein shown and described the preferred embodiment of the invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

I claim:

l. ln combination with a ladder having side rails and cross rungs, an extension leg formed of two members, one of said members being fixed to a side rail and the other member slidable on the xed member, the xed member having a longitudinally extending rib, a pair of controlled oppositely operating wedge devices carried by the slidable member engageable with said rib for holding the slidable member against movement on said xed member.

2. In combination with a ladder having side rails and cross rungs, an extension leg ormed'of two members, one of said members being xed to a side rail and the other member slidable on the fixed member, the fixed member having a longitudinally extending rib, a pair of controlled oppositely operating wedge devices carried by the slidable member engageable with said rib-for holding the slidable member against movement on said xed member, and manually operated means for selectively rendering one of the wedge devices inoperative whereby the slidable member may be moved in one direction.

3. In combination with a ladder having side rails and cross rungs, an extension leg formed of two members, one of said members being fixed to a side rail and the other member slidable on the xed member, the xed member having a longitudinally extending rib, a pair of controlled oppositely operating wedge devices carried by the slidable member engageable with said rib for holding the `slidable member against movement on said xed member, the wedge devices including a pair of vertically spaced wedge blocks, a tensioned wedge roller associated with each block for wedging engagement between the blocks and iixed rib and manually operated means including a slide rod for shifting a wedge roller out of 3l and upward movement of wedging position relative to a wedge block and the rib.

4. In combination with a ladder having side rails and cross rungs, an extension leg formed of two members, one of said members being i'lxed to a side rail and the other member slidable on the fixed member, -the xed member having a longitudinally extending rib, a pair of controlled oppositely operating wedge devices carried by the slidable member engageable with said rib for holding the slidable member against movement on said xed member, and manually operated means for selectively rendering one of the wedge devices inoperative whereby the slidable member may be moved in one direction, the wedge devices including a pair of vertically spaced wedge blocks, a tensioned wedge roller associated with each block for wedging engagement between the blocks and Xed rib and said manually operated means including a slide rod for shifting a wedge roller out of wedging position relative to a wedge block and the rib. r

5. In combination with a ladder having side rails and cross rungs, an extension leg formed of two members, one of said members being fixed to a side rail and the other member slidable on the xed member, the fixed member having a longitudinally extending rib, a pair of controlled oppositely operating wedge devices carried by the slidable member engageable with said rib for holding the slidable member against movement on said Xed member, the wedge devices including a pair of vertically spaced wedge blocks, a tensioned wedge roller associated with each block for wedging engagement between the blocks and fixed rib and said manually operated means including a slide rod for shifting a wedge roller out of wedging position relative to a wedge block and the rib, and cooperating means carried by the two members for limiting extensible movement of the' slidable member relative to the fixed member.

6. In combination with a ladder having side holding the slidable `rails and cross rungs, an extension leg formed of two members, one of said members being xed to a side rail and the other member slidable on the xed member, the fixed member having a longitudinally extending rib, a pair of controlled oppositely operating wedge devices carried by the slidable member engageable with said rib for member against movement on said fixed member, and manually operated means for selectively rendering one of the wedge devices inoperative whereby the slidable member may be moved in one direction, the wedge devices including a pair of vertically spaced wedge blocks, a tensioned wedge roller associatedwith each block for wedging engagement between the blocks and fixed rib and said manually operated means including a slide rod for shifting a wedge roller out of wedging position relative to a wedge block and the rib, and cooperating means carried by the two members for of the slidable member member.

7. In combination with a ladder having side rails and cross rungs, an extension leg formed of two members, one of said members being xed to a side rail and the other member slidable on the fixed member, the fixed member having a longitudinally extending rib, a pair of controlled oppositely operating wedge devices carried by the slidable member engageable with said rib for holding the slidable member against movement on said xed member,` the wedge devices including a pair of vertically spaced wedge blocks, a roller associated with each block', a spring pressed pin engaged with each roller for moving the roller into wedging engagement with the block and rib, said pin being of tubular formation and carrying an oil saturated wick for oiling the roller, and manually operated means including a slide rod for shifting a wedge roller out of wedging position relative to a wedge block and the rib.

relative to the fixed JESSE G. WAKEMAN.v

limiting extensible movement

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