US2961060A - Extensible ladder and scaffold construction - Google Patents

Description

Nov. 22, 1960 1. B. TAYLOR EXTENSIBLE LADD ER AND scAFFoLD CONSTRUCTION Filed Ap ril 6 i ull lli.:

lllincllllk lll (unHnll INVENTOR JOHN B.TAYLOR ATTORNEY.

United States Patent 'e 2,951,060' Y EXTENSIBLE LADDER AND SCAFFOLD CONSTRUCTION John B. Taylor, Copiague, N.Y. (55 Underhill Ave., Syosset, N.Y.) Filed Apr. 6, 1959, Ser. No. 804,187 3 Claims. (Cl. 182-40) l 'I'his invention relates to an extensible ladder and scaffold construction. v y

The type of ladder and scaffold to which this invention pertains, is the professional type adapted for use by professional house painters, construction workers, building maintenance men, theater employees who change marquee signs and other persons who utilize ladders and scaffolds in the conduct of their business or employment. The invention is not intended to exclude use by non professionals, such as home owners who maintain their own homes as by painting and repairing them, but it will be apparent from the nature of the structure herein described and claimed that it is of greater use and advantage to those who always use ladders and scaffolds in the course of their business rather than to those who only occasionally use such devices, as would be the case with home owners. i

An important object of this invention is the provision of a combination ladder and scaffold which is vertically extensible to increase its height when in use and to decrease its height for storage purposes.

This is not a case of two or more conventional ladder sections which are slidably attached to each other for extension purposes. Instead, use is made in the present invention of at least one ladder section having a plurality of permanently spaced rungs, and at least one ladder section having a plurality of rungs which are movable relative to each other. In one extreme position these movable rungs are disposed at against each other for storage purposes. In the other extreme position they are supported in conventionally spaced relation to each other for purposes of use, this invention that the series of movable rungs are not operated simultaneously but rather one at a time to the extent required. Thus, it may only be necessary to elevate the uppermost of said removable rungs to an operative position, leaving the remaining movable rungs in stored positions. Should it be required that two movable rungs be elevated to operative positions, this may also be done, and so on to the extent of all of the movable rungs in the device.

An important feature of the invention is the mechanism which elevates the movable rungs, one at a time, and the means for rigidly supporting said movable rungs in their elevated operative positions, to avoid sagging, tilting or shifting. In short, the movable rungs in the present invention are securely supported in their elevated, operative positions.

Another object of the invention is the provision of an extensible ladder of the character described, which is provided at the top with a relatively large platform on which it is possible to stand comfortably and safely during working operations.

This feature of the invention is really its prime object. The extensible feature, the movable rungs, all of the other features, all of these render the working platform accessible and positionably adjustable. lt will therefore be understood that the working platform may be raised or lowered, as desired or as required to meet the needs of individual jobs, and that convenient access may be had to said platform, irrespective of its working elevation, by means of the rung assembly above described.

Another feature of the invention is the base which supports the ladder and scaffold in vertical operative posi- It is an important feature ofY 'i ce 2 tion. The base is mounted on wheels and may be moved from one location to another. It is also provided with means for firmly holding it in any given location. The

invention is not however limited to a ladder and scaffold construction mounted on a permanent base. The ladder is detachably mounted on the base and may be removed therefrom when it is desired to lean the ladder against the side of a building or other suitable support. In practice, the base is provided with a pair of sockets adapted to receive the side rails of the ladder. Said rails may be inserted into or removed from such sockets as desired.

The invention is illustrated in the accompanying drawing in which:

Fig. l is a front view of a combination ladder and scaffold construction made in accordance with this invention showing it in partly extended position.

Fig. 2 is a side view thereof.

Fig. 3 is an enlarged horizontal section on the line 3-3 of Fig. 2.

Fig. 4 is an enlarged horizontal section on the line 4-4 of Fig. 2.

Fig. 5 is an enlarged fragmentary vertical section on the line 5-5 of Fig. 1.

Fig. 6 isV an enlarged fragmentary vertical section on the line 6 6 of Fig. l.

The combination ladder and scaffold 10 shown in the drawing is provided with a base 12, a lower ladder section 14, and an upper ladder section 16. The base may be constructed in any desired manner and its horizontal dimensions should be such as to provide sutlicient stability to the entire device when it is in its fully extended position and supporting a man. In the preferred form of this invention, the front end of base 12 iS mounted onv a pair of wheels 18. The back end is mounted on a pair of pegs or legs 20. The base may beporting oor or ground and the entire structure wouldY thereby be confined to the selected location.

Lower ladder section 14 consists of a pair of channel members 14a and 14b respectively. At their lower end theseY channel members are removably mounted in sockets 15 formed in base 12. Upper ladder section 16 is also composed of a pair of channel members 16a and 16b respectively, said latter channel members being slidably and telescopically supported by the lower channel members 14a and 14b.

It will now be observed that a platform 3@ is secured to the upper channel members 16a and 16h, said platform projecting forwardly therefrom. Guard rails 32 are xed to the sides of saidplatform and to said channel members 16a and 16b in order to provide adequate support for said platform and also asa safety feature to prevent the occupant of the platform from falling olf. Also secured to the` upper channels 16a and 1612 is a plurality of rungs or steps 34. It will at this point be stated that the inven-V below said platform. In addition are movable steps below xed steps 34.

Turning now to the lower ladder section 14, it will be seen that stored within its two channels 14a and 14b is a plurality of steps 40. These steps resemble steps 34 and 35 of the upper ladder section'16 in that they arejmade in channel form with their respective side flanges projecting downwardly. The lowermost step 35 is situated at the lower end yof ladder section 16 and when said ladder section 16 is in its lowermost position, said bottom step 3S is disposed in close proximity to the uppermost step Y40.

It will now be observed that between the lowermost step 35 and uppermost-step 40'and also between each adjacent pair of steps 40, is a pair of folding brace supports 42. Each brace support consists Vof a pair of hingedly connected plates or bars 42a and 42b respectively, hinged not only to each other but also to the adjacent steps above and below them. The hinged connections between each pair of bars 42a and 42h are off center asthe drawing clearly shows. lThe reason for this will shortly become apparent. Similar Vfoldingbrace supports are provided between vlowermost step 34 and uppermost step 35 and also between steps 35. e

A winch 50 is mounted on channel 14b. This is a conventional winch having a pawl-and-ratchet locking mechanism. Two cables or ropes 52Yand 54 respectively are wound upon the drum of said winch and it will be observed that they are so related that they. are simultaneously payed out or drawn in by the operation of -the winch, depending upon its direction of rotation. Cable 52 extends downwardly and around a pair of pulleys 56 and 58 respectively supported on base12 or on the lower ends of channels 14a and 14b. Cable 52 `then con- Atinues upwardly and around pulley 60 mounted at the top of channel 14b. The cable then continues downwardly 'to a rod 61 on the lowest step 34 to which it is firmly secured. I Cable 54 extends upwardly from the Winch and.

then around pulley 62 which ismounted at the-upper end 'of channel 14a. -The cable then continues downwardly to the opposite end of rod 61 to which it is secured.

vIt will now be evident that when the winch is operated one angular directiomthe cables Ywill Ybe drawn in and wound upon its drum. This will cause channels 16a and 16b to move upwardly and they may be Ylocked in any desired elevated position by means of the conventional pawl-and-ratchet mechanism of the winch. Remembering that the lowermost step 34 in channels 16a and 16h is connected to the uppermost step 34, and that steps 34 are interconnected and also connected to` steps 40 in channels 14a and 14b, all by means of hinged brace supports 42, it will be understood that the upward movement of said lowermost step 34 will eventually cause an upward movement of the uppermost step 35, said hinged. brace supports 42 serving as. the pulling means. Similarly, as

The foregoing is illustrativeyof a preferred form of this invention and it will be understood that this preferred form may be mOdied and other forms may be provided within the broad scope and principles of the invention.

I claim:

1. An extensible ladder construction of the character described, comprising a lower pair of parallel channels, an upper pair of parallel channels slidably telescopcally disposed in the lower'channels, a plurality of steps lixedly secured to the upper ends of the upper channels, a plurality of steps slidably mounted in said upper channels below said Vtxe'd steps, a plurality of steps slidably mounted in the lower channels, hinged braces between the slidable Vsteps in the upper channels, additional hinged braces between the slidable steps in the lower channels, and hinged braces between'the lowermost slidable step in the upper channels and the uppermost slidable step in the lower channels, a winch on one of said lower channels, cables operatively connected to said winch, pulleys at the upper and lower ends of said lower channels, one of said cables extending downwardly and around the pulleys at the lower ends of the lower channels and then upwardly and around the pulley at the upper end of one of said lower channels and then down to the corresponding upper channel Vto which it is secured, the other cable extending upwardly and around the pulley at the upper end of the other of said lower channels and v then downwardly to the corresponding upper channel to which it is secured, whereby operating the winch in one direction causes'the upper lchannels to move upwardly relative to the lower channels and to raise the slidable steps, rst of the upper channelsV and then of the Vlower channels, by means o'f said hinged braces, whereby operating the winch in the opposite direction causes the upper channels to descend and thereby to lower the slidable steps, lirst of the lower channels and then of the upper channels, each of the slidable steps in the upper and lower channels, and the lowermost of the fixed steps Vin the upper channels, comprising a channel of inverted U-shape in cross section, the yoke of the U-shaped channel comprising the step proper and the legs comprising a pair of downwardly extending flanges which extend along both side edges of the yoke, the

said uppermost step 35 is moved .into elevated position,

it will pull into elevated position the second step 35 Yin line and by the same token, said second step will pull the third and the third will pull the fourth and so` on until all of the stored steps 35 are supported in elevated positions, properly spaced from each other. The lowermost step 35 will pull uppermost step 40 into elevated position, and this will then happenV to the succeeding steps 40 until all are raised into vertically spaced, elevated positions. Y Y.

When it is desired to lower the upper ladder section 16 and the platform unit mounted thereon, the lock on the winch is released and the winchA is caused to operate in the opposite direction from that previously indicated. Steps 40 andV then steps 35 will move downwardly and each in turn, beginning with the second step fromsthe bottom, will move into abutment Ywiththe step below it. Each pair of hinged braces 42 will fold upwardly into the step above. `This would happen because of the offset positions of theirV respective hinges. the upper ladder section 16 and the'platform unit will position is attained.

At the same time,

hinged braces being pivotally secured to said anges on the inside thereof and being adapted to fold into the space between said anges to permit nesting of said slidable steps one upon the other.

2. An extensible ladder construction in accordance with claim 1, 'wherein said ladder construction is provided with a base receptacle adapted to receive and store the slidable steps in their lowermost postions, said ladder construction also having a base support mounted on wheels, said base support having a pair ofrsockets formed therein and said lower channels being removably mounted in said sockets, the winch being providedwith a pawl and ratchet locking' mechanism adaptedto lock References Cited in the file of this patent UNITED STATES PATENTS Cooper Apr; 16, 1895 987,585 Mayer Mar. 21, ,1911 1,101,808 Michel June 30, 1914 2,310,119 Reinhardt Feb. 2, 1943 v2,762,659 Harlan Sept. '11, 1956 2,829,814 v Warner Apr. 8, 1958

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