US2536318A - Ladder - Google Patents

Description

Jan. 2, 1951 slLER 2,536,318

I LADDER Filed 0st. 30, 1946 3 Sheets-Sheet l I I ma 7 ii INVENTOR.

= m1 ,czwwalva 6145K ATTORNEYS L. SILER Jan. 2, 1951 LADDER 3 Sheets-Sheet 2 Filed 00 50, 1946 INVENTOR.

ATTDRNEVS Jan. 2, 1951 L. SlLER 2,536,318

LADDER Filed Oct. 30, 1946 3 Sheets-Sheet 3 :2... 54' s 50 50 E 5; 3E .54

INVISNIOR.

Zfr/va/m 5/419? ATTORNEYS Patented Jan. 2, 1951 UNITED STATES PATENT OFFICE LADDER Leymond Siler, Knoxville, Tenn. Application October 30, 1946 Serial No. 706,554

3 Claims.

My present invention relates to an improved ladder and more particularly to an extension type ladder especially designed for use in airplane crash rescue work wherein a minimum number of men will be required.

The ladder of my invention comprises generally two extensible sections, the upper section having spring extended hooks for engagement with the airplane body or wing and adapted to be placed in position first, whereupon the lower section is reelased to drop by gravity to engagement with the guard or base, and means for securing the sections in extended position.

In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention according to the best mode I have thus far devised, but it will be understood that various changes and alterations may be made in the exemplified structure within the scope of the appended claims.

In the drawings:

Fig. 1 is a front elevational view of the ladder in retracted position.

Fig. 2 is a similar view with the sections extended.

Fig. 3 is a transverse sectional view at line 3--3 of Fig. 2.

Fig. 4 is a horizontal sectional view at line 44 of Fig. 2.

Fig. 5 is a horizontal sectional view at line 5-5 of Fig. 1.

Fig. 6 is a vertical sectional view of the hook extension mechanism.

Fig. 7 is a detail in section of the base at of Fig. 1.

Fig. 8 is a horizontal section at line 88 of Fig. 1.

Fig. 9 is a, horizontal sectional view at line 99 of Fig. 6.

Fig. 10 is an enlarged detail of the hook mechanism.

Fig. 11 is a front elevational view thereof.

Referring now to the drawings, I employ an upper ladder section having legs 2 and 4 tubular in shape and having longitudinal slots 6. Rungs 8 are secured to the legs 2 as at It by suitable means and disks [2 are secured to the upper ends of the legs 2 and 4 by the caps l4 threadedly engaging the legs at l6. Within these caps I provide the partition l8 having a squared opening to receive the square end 22 of the rod 24. Springs 26 and 28 within the cap and retained by washers 30 and 32 permit vertical movement of the rod and its squared end to be depressed or raised so that the rod may be rotated in either 2 direction and then spring back to locked position. Closure 33 secures the upper open end of the cap.

In the upper ends of the rods 24 I utilize fork extensions or yokes having legs 34 and 36 in which shafts 38 are rotatably mounted. 0n the shafts 38 are hooks having hubs 40 from which extend arcuate long fingers 42 and short fingers 44, the former being pointed at 46 for pressing into the airplane skin and the latter rounded at 48 to prevent damage, it being apparent that the fingers or prongs may also engage the thin edge of a ring without using either of the fingers or prongs.

The snap spring 50 secured between the forks by screws 52 has a shoulder 54 engaged by the prong 42 and depression of the end 54 of the spring 50 will permit the coil spring 56 secured to the fork at 58 and curved around post 60 to pull the prongs, through eye 62, to extended position so that the arc 64 adjacent the hub engages the post 60.

The upper section of the ladder is normally adjusted and placed in position first.

Then the lower section comprising tubular legs 66 and 68 secured by rings 10 is lowered. The lower end of the legs 2 and 4 are curved at 12 to form a ball race for ball bearings 14 to facilitate the lowering of the lower section, and the upper ends of the legs 66 and 68 are provided with yokes 16 for balls 18 on shafts to reduce friction, it being understood that clearance is maintained between the telescoping ladder legs.

To secure the sections in extended or adjusted position, I use the forked clamps 82 piv otally secured at 84 to supports 86 mounted by screws 88 to the legs 2 and 4, and engageable with the pins 9|] in arms 92, pivotally secured to supports 94. In Fig. 8 inward movement of the extension 9% will disengage the pins 90 from the hooks 98 of the clamp and the clamp may be pivoted to afford clearance for elevating or lowering the lower section.

Caps [M are threadedly secured at I92 to the lower ends of the legs 66 and 68 and formed with removable points I04 which engage the ground to secure the lower end of the ladder.

Thus the ladder in use will be secured at the top and bottom eliminating the need foreman to hold the ladder and making for fasterand more efficient rescue work.

I prefer that the ladder be made of strong, lightweight metal as Duralumin which requires no painting or other upkeep and it will be obvious that while my ladder is designed especially for airplane crash rescue work, it will have limitless uses in any field requiring ladder use.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. In an extension ladder, the combination which comprises a plurality of ladder sections having rungs carried by telescoping side rails,

rods having yokes on the upper ends mountedorr the upper ends of the side rails of the upper rods ,hav ing :yokes on the upper ends mounted on the upper ends of the side rails of the upper telescoping :section of the ladder, hooks having outwardly extended areuate long fingers with substantially. pointed-outer endsand-short fingers with rounded ends extended from hubs, means pivotally mounting the books through the hubs thereof between arms of the yokes, springs attached to the yohes and hooks for urging the said hooks upwardly, and spring clips for temporarily retaining the said hooks in folded positions within the said yokes, said spring clips having outwardly extended arms-positioned to be engaged 'by a surface upon which the upper-end of the z-ladder is positioned whereby upon engagement of the said arms in an upward movement of the ladder the hooks are released.

3. In an extension ladder, the combination which comprises aplurality of ladder sections having rungs carried by telescoping side rails, rods having yokes on the upper ends mounted on the upper ends of the side rails of the upper telescoping section of the ladder, hooks having outwardly extended arcuate long fingers with sub- Jstan'tially pointed outer ends iandzshor't fingers with rounded ends extended "from hubs, means pivotally mounting the hooks through the hubs thereof between arms of the yokes, springs attached to the yokes and hooks for urging the said hooks upwardly, spring clips for temporarily retaining the said hooks in folded positions within the said yokes, said spring clips having outwardly extended arms positioned to be engaged by La, surface upon which the uper end of the ladder is positioned whereby upon engagement of the said arms in an upward movement ofthe ladder thehooksare released, and means limiting upward movementof the ,said hooks.

LEYMOND SILER.

REFERENCES CITED The following: references are of record in the file of 'this'patent:

UNITED STATES PATENTS Number Name Date 283,391 Hart .Aug. .21, 1,883 434,176 Crafts Aug. 1-2, 18.90

1,217,279 Coughtry Feb. 27, 917 1,712,942 Smith May 14, 1929 1,731,611 Clark Oct. 15, 1929 2,127,035 Kirlin Aug. 15, 19.38 2,256,452 Marshall 1 Sept. 16, 194i].

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