US2993561A

US2993561A - Collapsible ladder

Info

Publication number: US2993561A
Application number: US833552A
Authority: US
Inventors: Cyril J Watson
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-08-13
Filing date: 1959-08-13
Publication date: 1961-07-25
Anticipated expiration: 1978-07-25

Description

July 25, 1951 c. .1. wATsoN 2,993,561

COLLAPSIBLE LADDER 2 Sheets-Sheet 1 Filed Aug. 13, 1959 9 Cyr/'l J. Wafson ZNVENTOR.

' BY ana/Wawy July 25, 1961 c. J. wATsoN 2,993,561

coLLAPsIBLE: LADDER Filed Aug. 1s, 1959 2 sheets-sheet 2 Y Cyr/'l J. Watson INVENTOR.

United States Patent O 2,993,561 COLLAPSIBLE LADDER Cyril J. Watson, 209 Buckingham Drive, Riverside, Gntario, Canada Filed Aug. 13, 1959, Ser. No. 833,552 Claims. (Cl. 182-195) rIfhis invention relates to new and useful improvements in straight ladders of the extension type and has for its primary object to provide, in a manner as hereinafter set forth, a ladder of this character comprising a plurality of sections which may be telescopically collapsed to require a of space when said ladder is not in use.

Another very important object of the present invention is to provide novel means for securing the sections of the ladder in collapsed or telescoped position.

Other objects of the invention are to provide a telescopic ladder of the character described which will be comparatively simple lin construction, strong, durable, of light weight, safe and which may be manufactured at low cost.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings Iforming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE l is a view in front elevation of a ladder constructed in accordance with the present invention, showing the device extended;

FIGURE 2 is a perspective View of one of the intermediate sections;

FIGURE 3 is a view in horizontal section on an enlarged scale, taken substantially on the line 3-3 of FIGURE 2 with parts omitted;

FIGURE 4 is a cross-sectional view on an enlarged scale, taken substantially on the line 4 4 of FIGURE 3;

FIGURE 5 is a view in side elevation, showing the ladder extended;

FIGURE 6 is a rear elevational View, showing the ladder collapsed; and

FIGURE 7 is a perspective view, showing the means for securing the sections in collapsed position and for carrying the same.

Referring now to the drawing in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a stationary lower section 8, a plurality of telescopically slidable intermediate sections 16 and `a slidable upper or top section 17.

The lower section 8 comprises a generally inverted U- shaped tubular base 9 of suitable metal. Rising from the base 9 is a pair of inwardly opening posts 10 of substantially C-shaped horizontal section. Extending through the upper end portions of the posts 10 and xed in openings provided therefor in said posts is a tubular metallic rung 11. As shown to advantage in FIGURE 3 of the drawing, the rung 11 has formed therein at an intermediate point a slot i12. Bolts or pins 13 are mounted for reciprocation in the rung 11 and adapted lto project beyond the ends thereof. A coil spring 14 is mounted in the rung 11 between the lock bolts or pins 13 for yieldingly urging same outwardly toward operative position. Tabs or handles 15 are xed on the inner ends of the bolts or pins 13 for retracting the same against the tension of the spring 14, said tabs or handles being operable in the slot 12.

The lowermost intermediate section 16 is generally inverted U-shaped and comprises tubular metallic legs 18 which slidably receive the posts 10 of the lower section 8. The legs 18 are longitudinally split from end to end to provide slots 19 which accommodate the rung 11.

2,993,561 Patented July 25., 1961 Fixed in openings provided therefor -in the upper end portions of the legs 18 is a tubular rung 20 which is substantially similar to the rung 11. Spring projected, manually retracted lock bolts or pins 21, substantially similar to the elements 13, are mounted in the rung 20. The lower end portions of the split, tubular legs 18 are provided with openings 22 for the reception of the bolts 13 for locking the lowermost intermediate section 16 in raised or extended position on the lower section 8. The several intermediate sections 16 are substantially similar structurally, being telescopioally connected.

The upper or top section 17 of the ladder is generally inverted U-shaped and comprises longitudinally split legs 23 which telescopically receive the legs 18 of the uppermost intermediate section 16. Fixed in the upper end portions of the legs 23 of the top section 17 is a rung 24.

Hingedly mounted, as at 25, for vertical swinging movement on the base 9 between the posts 10 is a metallic bar 26. Fixed on the free end portion of the bar 26 is a generally U-shaped anchoring head 27. The head 27 includes a bar 2S aixed to the bar 26, from which bar 28 legs 29 extend. It will be observed that the legs 29 comprise sharpened or pointed free ends. Extending between the legs 29 is a carrying handle or grip 30. Mounted on the bar 28 between the legs 29 is a pair of detents or lugs 31. The detents 31 are engage-able in openings 32 which are provided therefor in the free end portion of anV angular latch 33 which is hingedly secured, as at 34, on Ithe rung 24 of the top section 17. The latch 33 is adapted to be snapped or sprung into engagement with the detents 31.

It is thought that the use of the ladder will be readily apparent from a consideration of the foregoing. Briey, when the ladder is to be erected the several sections comprising said ladder are extended as shown in FIGURES l and 5 of the drawing. The sections are automatically locked inextended position by the spring projected bolts or pins 13. The upper section 17 is substantially similar to the intermediate sections 16 in that the lower end portions of the legs 23 thereof are provided with openings similar to the openings 22 for the reception of the locking bolts 13 of the subjacent section. To collapse the ladder the

bolts

13 and 21 are manually retracted to an inoperative position against the tension of the springs 14 through tne medium of the handles or -tabs 15. As shown in FIG- URE 5 of the drawing, the arm 26 with the head 27 on the free end portion thereof is adapted to anchor the lower end of the ladder. To secure the telescopic sections in collapsed position, the bar 26 is swung upwardly and forwardly and the hinged latch 33 is engaged in the generally U-shaped head 27. The construction and arrangement is such that the latch 33 is tensioned when it 1s forced into the head 27 and the detents 31 snap into the openings 32. The collapsed ladder may then be conveniently carried through the medium of the handle or grip 30. The foregoing is considered as illustrative only or the principles of the invention. Further, since numerous modications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope ot the invention as claimed.

What is claimed as new is as follows:

l. In a collapsible ladder structure, the combination of a base section comprising an inverted U-shaped member having a horizontal cross bar and a pair of downwardly extending legs rigidly connected to the ends of said cross bar, a pair of spaced vertical tubular members extending upwardly from said inverted U-shaped member and secured at their lower ends to said cross bar at points spaced inwardly from said legs, a tubular rung connecting to- 3 Y gether upper end portions of said tubular members, end portions of said rung extending diametrically through the upper end portions of the tubular members and terminating in openings ilush with outer sides of the tubular members, a pair of latch members slidable in said rung and projectable and retractable through said openings, an extension ladder section comprising a pair of spaced vertical tubular side pieces, and a rung connecting together upper end portions of said side pieces, said side pieces having opposing inner sides provided with open-ended ver-tical slots, end portions of said last mentioned rung passing through said slots diametrically of the upper end portions of the side pieces and terminating ush with outer sides of the side pieces, said side pieces being slidable on said tubular members of said base section with the rung of said tubular members sliding in said slots, the lower end portions of said side pieces being provided at their outer sides with apertures registrable with said openings to receive said latch members when the extension ladder section is slid upwardly on the tubular members of the base section, and vadditional extension ladder sections slidably telescoped on one another and on the side pieces of the first mentioned extension section, said additional sections including a top section having a rung, and means for locking the various sections in collapsed relation, said means comprising a strap pivoted at one end thereof centrally to the cross bar of the base section and having its other end disposed adjacent the rung of said top section when the sections are collapsed, a keeper pivoted to the rung of said top sectionand formed with an aperture defining a keeper seat, and a detent provided at the other end of said strap, said keeper being swingable to a locking position wherein it overlies said strap and wherein said detent is lockingly received in said keeper seat.

2. The structure as dened in claim 1 together with a carrying handle provided on said other end of said strap.

3. In a collapsible ladder structure, the combination of a base section including a horizontal cross bar and a pair of transversely spaced side members secured to and extending upwardly from said cross bar, a plurality of extension ladder sections slidably telescoped on one another and on the side members of said base section, said additional sections including a top section having a rung, and means for locking the various sections in collapsed relation, said means comprising a strap pivoted at one end thereof centrally to said cross bar and having its other end disposed adjacent said rung when the sections are collapsed, a keeper pivoted to Ysaid rung and -formed with an aperture deiining a keeper seat, and a detent provided at said other end of said strap, said keeper being swingable -r to a locking position wherein it overlies said strap and wherein said detent is lockingly received in said keeper seat.

4. The device as deiined in claim 3 together with a carrying handle provided on said other end of said strap.

5. In a collapsible ladder structure, the combination of a plurality of slidably telescoped extensible ladder sections including a base section and a top section, said base section including a cross bar, said top section including a rung, and means for locking said plurality of sections in collapsed relation, said means including a strap pivoted at one end thereof to said cross bar and having its other end disposed adjacent said rung when the sections are collapsed, a keeper pivoted to said rung and formed with an aperture defining a keeper seat, and a detent provided n on said other end of said strap, said keeper being swingable to a locking position wherein it overlies said strap and wherein said detent is lockingly received in said keeper seat.

References Cited in the ile of this patent UNITED STATES PATENTS 530,374 Wilkins Dec. 4, 18914 933,816 Bartos et al Sept. 14, 1909 1,217,279 Coughtry Feb. 27, 1917 1,712,942 Smith May 14, 1929 1,852,976 LaRoy Apr. 5, 1932 1,859,984 Reese Mayl 24, 1932 2,127,949 Leman Aug. 23, 1938 2,194,856 Kostuk Mar. 26, 1940 2,523,535 Little Sept. 26, 1950 FOREIGN PATENTS 334,409 France Sept. 30, 1904