US722498A - Adjustable scaffold. - Google Patents

Description

No. 722,498. P'ATENTED MAR. 10, 1903: 0. C. DONEGKER & J. A. NAGLE.

ADJUSTABLE SCAFPOLD.

APPLICATION FILED SEPT. 5. 1902.

H0 MODEL.

.IIMIJI 4 UNITED STATES PATENT OFFICE.

ORN DONECKER AND JACOB A. NAGLE, OF ALLENTOWN, PENN- SYLVANIA.

ADJUSTABLE SCAFFOLD.

SPECIFICATION forming` part of Letters Patent No. 722,498, dated March 10, 1903.

Application filed September 5, 1902. Serial No. 122,254. (No model.)

T0 @ZZ whom t 11i/Cty concern.;

Be it known that we, ORIN C. DONECKER and JACOB A. NAGLE, citizens of the United States, residing at Allentown, Lehigh county, State of Pennsylvania, have invented a new and useful Improvement in Adjustable Scaffolds, of which the following is a specification.

Our invention consists of a novel construction of adjustable scaolds wherein novel means are provided for raising the scaold and for locking the same in its adjusted position, means being provided for supporting the locking-pawl in a very rigid and eective manner, so that the structure is very strong and efficient under all conditions.

Figure l represents a side elevation, partially in section, of an adjustable scaffold embodying ourinvention. Fig. 2 represents a front elevation of one of the standards seen in Fig. 1. Fig. 3 represents, on an enlarged scale, a perspective view showing the manner of bracing the upper portion of the uprights and securing the locking-pawl in position. Fig. 4 represents a section on linea: Fig. l. Fig. 5 represents a side elevation of the elevating device seenin Fig. 1. Fig. 6 represents a front elevation of Fig. 5; Fig. 7 represents a side elevation of the locking-pawl in adetached position. Fig. 8 represents a front elevation of Fig. 7.

Similar numerals of reference indicate corresponding parts in the figures.

Referring to the drawings, 1 designates the base of the standards, from which extend the substantially parallel uprights 2 and 3, said uprights being braced by the irons 4.

5 represents a rack-bar which is located between the uprights 2 and 3 and is provided with ratchet-teeth 6, which are engaged by the nose of the pawl 7, which is mounted on the pin 8, which latter projects through a tion, since it is adapted not only to reinforce the upper portion of the parallel uprights 2 and 3, but it also serves as a bearing for the ends of the pin or rod 8,'which supports the pawl. It will be apparent to those skilled in the art that it is necessary that the supporting device, as the pawl 7, which sustains the weight of the bar 5 and scaffold 12, must be as rigidly supported as possible, and by locating the ends of the supporting-pin 8 in the metallic or other band 9 as described a durable and efficient structure is produced, as is evident.

13 represents a band surrounding the upper portion of the uprights 2 and 3, so that said uprights are held in a relatively fixed position. The-.bar 5 is raised by the application of the pawl 14 to the ratchet-teeth 6, said pawl being pivotally mounted in the lever 15,which is fulcrumed on the pin 1G, mounted in suitable bearings.

It will be apparent to those skilled in the art that in practice a plurality of standards or supporting devices, such as the uprights 2 and 3, are employed and that the scaold or ooring 12 is supported at or near its extremities or outer portions, so that all portions thereof are rigidly sustained. The rack 5 is raised by rocking the lever 15 on its'fulcrum, and it will be apparent that a downward movement of the scaffold 12 and said rack 5 will be prevented by the engagement of the end of the pawl 7 with the contiguous ratchetteeth. It will also be apparent that the pin S, which supports the pawl 7, is firmly secured in position by means of the reliable engagement of its ends in the band 9, so that the latter serves not only to reinforce the upper` ends of the uprights 2 and 3, but it also serves to strengthen the upright 3 around the groove 10 where it is weakest.

It will be apparent that various changes may be made by those skilled in the art which may come within the scope of our invention, and we do not, therefore, desire to be limited to the exact construction herein shown and described.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is-

1. In an adjustable scaold, a plurality of IOO uprights, a rack-bar supported between'said uprights, a slot in one of said uprights, a band surrounding said uprights in proximity to said slot, a spring-pressed pawl mounted in said slot, a pin supporting said pawl and extending transversely over said slot and hav-- is supported, each of said rack-bars being held between uprights, a slot in one of said uprights, a band around said uprights and slot, a pawl mounted in said slot, a pin supporting said bar and havingits ends located in said band, a lever pivotally mounted on one of said uprights and a pawl carried by said lever and adapted to be moved in unison therewith for the purpose of raising said rack-bar.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

ORIN C. DONECKER. JACOB A. NAGLE.

Witnesses:

W. D. STERNER, B. A. LAUB.

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