US588982A - Scaffold - Google Patents

Description

2 Sh88ts sheet l. W' E' GRAY.

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W. H. GRAY. SGAFPOLD. No. 588,982. Patented Aug. 31, 1897.

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A 09 90 Igvxefgfaar-l y Z- mms mum' vJ'fdmy coner, in the county of Chautauqua and State .conjunction with the standards or uprights one of the brake-shoes and one of the grapple'- UNITED STATES PATENT 'OFFICE'.

V WILLIAM Il. GRAY, OF FALOONER, NEW YORK.

scAFFoLD."

SPECIFICATION forming part of Letters Patent No. 588,982, dated August 31, 1897.

Application nea umh 31,1897.

To all whom t may concern,.-

Be it known that I, WILLIAM 1I. GRAY, a citizen of the United States, residing at -Falof New York, have invented a new and useful Scaiold, of which the following is a specification. j l

This invention relates to an improvement in scaffolds, and has for its object to provide an improved construction of scaffold which may be knocked down when not-in use and stored com paetly and which may be easily and quickly set up and placed in position for use when needed. A

One of the principal objects of the invention is to provide, in connection with the mov-l able scaffold-bed, an improved construction of brakeor safety appliance which in the event of the breakage of one of the hoisting or supporting ropes would operate automatically, in

of the device, to arrest the downward progress of the scaffold-bed and prevent serious'accident which would otherwise occur. lhese andl other objects of the invention will appear more fully in the ensuing description.

'Theinvention consists in certain novel features and details of construction and arrange ment of parts, as hereinafter fully described, illustrated in the drawings, and finally pointed out in the claims.k

'In the accompanying drawings, Figure 1 is a perspective view of the improved scaffold, looking from the inner side o r the side next adjacent toa building when in position. I Fig. 2 is a view in elevati'on looking from the opposite side. Fig. 3 isa vertical transverse section taken in line with the tubular uprights of one of the end supports. Fig. 4 is an irregular detail section through one of the stage-planks and detachable Work beneh, showing the manner of att-aching the latter. Fig. 5 is a reverse perspective view of the intermediate stage plank. Fig. 6 illustrates hooks in detail.'- Fig. 7 is a detail sectional Aviewshowing the extension-plugand the manner of coupling together adjacent sections oi an upright. Fig. 8 is a detail section through the top cross-bar and upper end of one of the tubular uprights.

Similar numerals of reference designate Serial No. 630,171. (No model.)

corresponding parts in the several figures of the drawings. f

The present invention contemplates the use of two separate and independent end supports which are for the sake of eheapness of manufacture and uniformity the counterpart of each other, so that it will bev necessary to describe but'one of them. Each of these supports comprises a suitable base 1, consisting lof suitable crossed arms disposed at right angies to each other for the purpose of giving sufficient breadth to the base. Malleable-iron sockets 2 are mounted in .thebasel, being spaced asuitable dist-anceapa'rt and adapted to receive the lower extrernitiefJ of a pair of.

standards or uprights 3. 'lhese standards or uprights are tubular, being made preferably from malleable-iron pipes, and their lower ends, which are received in the sockets 2, are

perforated in alinement with other perforations in the sockets 2 to receive stay-pins 4,. removably inserted therein and anchored to the base by suitable chains or flexible connections 5.

The tubulaiuprights 3 may be made of any desired length, and, it' desired, similar exten- -sion-uprightsmay be applied to the upper exv nected by a horizontal cross-head 8, which is l preferably formed of wood andv has inserted in its lower surface metal thimbles or sockets 9, in .which the upper ends of the uprights are received and which provides for deta'eliing the cross-head when taking down he scaffold.

Arranged above the cross-'head 8 and secured thereto adjacent toeach end-are metal bracketsl0, arrangedl in pairs and spaced apart and forming the bearings in which are journaled grooved pulleys l1, over which runs One pair of brackets,

the hoisting-rope 12. that pair next to' thebuilding, is formed with opposing notches 13, in which are received the hooked terminals of a V-shaped grapple 14, fast to one endA of the hoisting-rope 12. The ends of the cross-head 8 areslotted, as at 15, for the'passage of the rope 12, and also have secured to the opposi te side faces thereof metal eyes 1G for the reception of suitable guy-ropes which may extend from one end support to the other and from each cross-head 8 to the ground or other convenient point of attachment for imparting the necessary endwise rigidity to the scaffold.

17 designates the ,scaffold-bed, which comprises an upper cross-bar 18 and a'lower crossbar 19, the said bars being spaced apart by .The upper and lower cross-bars of the scaffold-bed are held together centrally by a tiebolt 21. vThe lower cross-bar 19 is'slotted adjacent to its ends and outside of the uprights, and within these slots are journaled grooved pulleys 22, around which runs the hoistingrope-12, one end of said rope being secured to the inner end of the cross-head. 8, as above described, and the opposite end heilig wound around a windlass 23, mounted in suitable bearing-arms 24, arranged preferably'at the outer end of the scaffold-bed and being of suicient length to rigidly connect and brace the bars 18 and 19 and extend sufficiently above the former, to receive the said wind lass. The shaft of this windlass is extended through and beyond the arms in which it is journaled and has both of it-s ends squared for the reception of an operating hand-crank 25, which may thus be employed at either end of the windlass, as convenience may dictate.

Thewindlass hasv circumferential anges adjacent to eachend, one of which is provided with peripheral ratchet-teeth, as shown at 26, for engagement with a pivoted gravity-dog 27, mounted on one ofthe bearing-arms, as shown. This arrangement, of course, prevents the unwinding of the rope and holds the stage elevated until the dog is thrown out of engagement. The hoisting-rope 12 works through openings at the proper ypoints in the upper cross-bar 18 of the scaiIold-bed.

The upper cross-bars 18 of each end support have secured to their inner and outer edges metal plates 28, the purpose of which is to engage suitable kerfs or grooves 29 in the ject of` this is to allow a third or a fourth end support tov be utilized where found necessary andthe stage-boardsto be brought together end to end to form a continuous platform. A

The outer board extends at'its outer edge in close proximity to the arms 24, while the inner board is held from sliding ot the inner ends of the bars 18 by means of metal 4stops or plates 3l, as shown. The intermediate stage-board has secured to its lower surface a transverse cleat 32, which extends at its op posite ends beyond the side edges of said board, so as to underlie the otherboards upon each side thereof, and thus prevent the uneven sagging of the boards. This sagging of the middle board, as well as the other boards,

is to a great extent prevented by means of a truss-'rod 33, which passes under the cleat 32- and is'secured at its ends to the end portions of the intermediate board of the stage.

To-the outer edge of thc outer board are attached a' series of metal sockets 34, which are adapted to receive the lower ends of the legs 35 of a work-bench. (Indicated at 36.) This work-bench comprises, essentially, a top or table and an upright support 37, and the work bench may be equipped with a vise 38 and with sawhorses 39, detachably connected thereto, and may be otherwise fitted out to add to the convenience of the workmen.

In order to prevent the descent of the stage upon the breaking of the hoisting, rope I of either end support, abrake mechanism is provided for each of said supports. Y This brake mechanism comprises a pair of brake-levers 40 and 41 of segmental form 4and pivotally mounted adjacent to their lowerends in slots in the lower cross-bar 19 of the stage-bed. To the lower extremities of these brake-levers are attached shoes 4 2, having concaved working faces which are -also toothed or serrated to insure their firm engagement with the tubular uprights 3. v

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The curved upper ends of the brake-levers i are crossed, as shown, and between the extremity of one of the levers 41 and the crossbar 19 is interposed a coiled spring 43, which exerts its tension to'hold the brake-shoe of its lever against its respective upright. The

other lever 40 is connected pivotally to the short arm of an elbow-lever 44, and said elbow-lever connects pivotally at its` elbow to the brake-lever 41, while the long arm of the elbow-lever is bifurcated to stride the inner sleeve 20, above referred to, inside of' which y to the under side of the cross-bar 18, and then passesl under the pulley atl the inner end ofthe lower cross-bar 19, and thence directly upward 'over the pulleys of the cross-head, then downward under the pulley at the outer end of the bar 19, and thence upward tothe windlass. It will thus be seen that the coiled spring 43 holds the-brake-shoes in operative engagement with the uprights, as the lever of the elbow-lever 44, will be lifted by such rope, and under such a disposition of the el-- bow-lever the brake-levers will be vibrated so as to withdraw their shoes from engage- .ment with the uprights, thus allowing the stage-bed to be moved freely up and down by the workman standing at that end of the stage and having the windlass under control.

From the foregoing description it will be seen that a very strong, durable,'and reliable scaffold is obtained and that the same is rendered particularly safe by reason of the brake mechanism above described, which, as has been shown, will operate automatically and be thrown into immediate action upon the parting of the hoisting-rope at any point.

It will also be apparent that the various parts of the scaffold may be easily and quickly disassoeiatcd and that when the scaffold is knockedl down the various parts thereof may y be stored compactly, or they will admit of ready transportation to and from the point of operation.

The scaffold is highly useful and convenient to all classes of workmen and laborers engaged in the construction of buildings, and matters may be greatly expedited by lowering the stage to the ground, loading the building materials thereon, and then by means of the hoisting mechanism carrying the stage to the required elevation.

The construction described is very light and portable and at the same time very strong and well braced.

Changes in the form, proportion, and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of this invention.

Having thus described the invention, what is claimed as new is 1. The combination of a suitable base, uprights mounted thereon and arranged in pairs, cross-heads connecting the upper ends of the uprights of each pair, a vertically-movable stage-bed guided by the uprights, hoisting mechanism suspending the stage-bed from the cross-heads, and the automatically-operating brakc mechanism carried by the stagebed and arranged to engage the uprights, said brake mechanism being held out of engagement with the uprights by the tension of the hoisting-ropes, substantially as and for the purpose described.

2. The combination with a suitable base, and uprights mounted thereon, of a movable stage-bed, hoisting mechanism carried thereby, and a brake mechanism comprising a pair of brake'levers having shoes and pivotally connected to the bed and to each other, a spring for throwing the brakeshoes against the uprights, and an arm or lever connected to the brake-levers and also having a sliding engagement with the hoisting-rope whereby the latter when under tension will hold the brake-shoes out of engagement with the uprights, while the breakingof the same will allow the brake-shoes to act through the assistance of the aforesaid spring, substantially as described.

3. The combination with'a suitable base and uprights mounted thereon,of a verticallymovable stage-bed mounted thereon, hoisting mechanism whereby the bed may be raised and lowered, and a safety appliance carried by the bed and comprising a pair of brakelevers having pivotal connection with the b'ed and carrying brake-shoes which work against the uprights, a spring connecting one of said levers with the bed and operating to hold the shoe of said lever against its respective upright, an elbow-lever having pivotal connection with both of said brake-levers and carrying a pulley at the swinging extremity of one of its arms, and aheisting-rope passing around said pulley and over other pulleys carriedby the bed, the arrangement being such that the tension of the rope holds the brake-shoes out of action while upon the parting of theirope, the shoes are1 thrown into action through the assistance of said spring, substantially as described.

4. The combination with a suitable base having a socket, of a tubular upright having its lower end seated in said socket and made in two or more sections, and a coupling-piece having shank or plug portions which enter the open ends of the tubular sections and also having intermediate its ends an annular enlargement or collar which lies between the adjacent ends of the tubular sections, substantially as and for the purpose described.

5. The combination with a suitable base having sockets, of tubular uprights having their lower ends in said sockets, a cross-head removably fitted upon and connecting the upper ends of the uprights and carrying at its ends brackets in which the pulleys are mounted, o ne of said brackets being formed with oppositely-disposed notches, and a hoist- 1n g-rope having attached to its end a V-shaped grapple the terminal portions of which are hooked to engage the aforesaid notches, substantially as described.

6. The combination with a pair of end supports having vertically-movable stage-beds mounted thereon, each bed comprising a horizontal cross-bar connecting the uprights of such end supports andhaving plates attached toits opposite side edges and projecting above the upper surface thereof, of a stage comprising one or more boards formed adjacent to their ends with grooves or kerfs in the under surfaces thereof, the said grooves or kerfs being adapted to receive the upper edges of said plates on the bed-pieces, substantially as and for the purpose described.

7. The combination with a stage-board provided at one edge with sockets, of a detach- IOO IXO

able work-bench mounted on the stage-board and projecting outward beyond the same,

said bench being provided at its outer sidel In testimony that I claim the foregoing as my own I have hereto axed my signature in the presence of two witnesses.

WILLIAM H. GRAY.

Witnesses:

PHILO RIDER, DANIEL SPEESE.

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