US783837A - Scaffold. - Google Patents

Description

PATENTED FEB. 28, 1905; R. G. JOHNSTON.

SCAFFOLD.

APPLICATION FILED MAY 6. 1904.

little. 783,837.

with Sairns Patented February 28, 1905..

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SCSAFl -"ULD.

SPECIFICATION forming part of Letters Patent No. 783,837, dated February 28, 1905.

. Application filed May 6, 1904. Serial No. 206,657.

To It Hill/0772' it may concern: I

Be it known that I, ROBERT G. JOHNSTON, a citizen of the United States, and a resident of Clearmontjn the county of Nodaway and State of li/lissouri,have invented a new and Improved Scaffold. of which the following is afull, clear, and exact description.

My invention relates to temporary supports for workmen, being particularly adapted for the use of linemen while at work upon poles. It has for its principal objects the provision of a simple, easily-portable, and secure scaffold.

.lt consists in the various features and combinations hereinafter described, and more particularly claimed.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a perspective view of a pole for supporting electric conductors with one embodiment of my invention applied thereto.

Fig. 2 is a top plan view of my device with the engaged member in section. Fig. 3 is a broken side elevation thereof, and Fig. 4 is a transverse section on the line 4t 4: of Fig. 2.

A designates the primary member of the support, which may consist of an integral bar, preferably of steel or iron. havinga main portion 10 bent at one extremity at 11 to furnish a surface upon which to secure a seat 12. This seat may be conveniently formed of sheet metal and preferably has its edges bent over at 13 to render it more comfortable for the user. The opposite extremity of the main portion extends outwardly at 14, it be ing here shown as curved, and carries at its outer end an arm 15, which may rise at substantially right angles therefrom. This arm is itself bent at an angle to extend at 16, first, in the same general direction as the portion 10 of the support and then curved at 17, so that its end lies in substantially the same plane as said main portion. At the extremity of this arm extending toward the portion 10 of the support is a sharpened engaging projection 18.

Mounted upon the supporting-bar is a contact member or bar B, which may comprise a stem 19 and an enlarged portion or head 20, here illustrated as having separated branches or of a general it shape. This contact member is adjustably retained in position upon the bar with the head in the space formed by the curvature at 14: by means of securing members which may conveniently consist of bolts 21, coacting with a longitudinal series of openings 22, formed through the portion 10 of the support and through the stem of the contact member. One or another of these pairs of openings may be brought into reg istration and secured by the bolts and in this way the relation of the contact-head to the engaging projection varied.

The use of the device will be obvious from Fig. l of the drawings. The lineman holding the supporting member with the seat in clined upwardly places the projection behind the pole and then brings the member B down into contact with the opposite sides. Then when weight is applied to the seat the contact member serves as a fulcrum, and by Vii" tue of the separation between it and the projection the latter is forced into the pole, the greater the weight the lirmer being the cngagement. The space between the branches of the Y causes them to engage considerablyseparated portions of the pole, serving to prevent lateral displacement. Thus it will be seen an extremely-secure support is obtained upon which the user may work safely. The vertical separation between the contact member and projection also permits the device to be applied to a'considerable range of size of poles by the turning it to an angle thereto when putting in place; but when the resulting angle of the seat to the pole becomes too great for com fort or safety the contact member may be adjusted upon the support to remedy this.

it will be further seen that my improved scaffold is comparatively inexpensive to construct and while amply strong is so lighttl'iatit may be readily carried by the user. It is also applicable to many other purposes than its use by linemen, such as that of carpenters in connection with pole-barns and also as a support for stagings.

Having thus d escribcd my invention, I claim as new and d osi re to secure by Letters Patent- 1. A scaffold comprisingamain bar having one extremity extending outwardly from the side ofsaid bar and being provided with an engaging projection, extending toward the main bar, a contact-bar secured to the side of the main bar, and means for adjusting the contact-bar along the main bar.

2. A scaffold comprising a bar extending at one extremity outwardly from the general plane otthe main portion, then substantially parallel to said plane, and finally back and being provided with an engaging projection in alinement with the bar, and a contact member adjustable on the main portion of the bar.

3. A scafiold comprising a main member having one extremity extending outwardly from the member, an arm carried by this extension and having an engaging projection, said arm extending inwardly and leaving a space between it and the outward extension, and a contact member mounted upon the main member and having an enlarged portion situated adjacent to the extension of said main member and lying in the space between such extension and the arm.

4. A scaffold comprising a main member having one extremity extending outwardly from the member, an arm carried by this extension and having an engaging projection, said arm extending inwardly and leaving a space between it and the outward extension, a contact member mounted upon the main member and having an enlarged portion situated adjacent to the extension of said main member and lying in the space between such extension and the arm, and means for adjusting the position of the contact member with relation to the engaging projection.

5. In a scaffold, the combination with a supporting-bar comprising a main portion, a curved portion and an angular arm, of a contact-bar secured to the supporting-bar and extending between the curved portion and the arm, the end of the contact-bar adjacent to said arm being provided with branches.

6. In a scaffold, the combination with a supporting-bar comprising a main portion, a curved portion and an angular arm, of a contact-bar mounted upon extending along the supporting-bar and between the curved portion and arm. said bars being each provided with a plurality of openings which may be moved into registration, and securing means engaging the openings. I

7. A scaffold comprising a bar extending at one extremity outward from the general plane of the main portion, then substantially parallel to said plane and finally back and being provided with an engaging projection opposite the bar, and a contact member adjustable upon the main portion of the bar and having branches at its inner end.

in testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

R-OB'ERT Gr. JOHNSTON.

lVitnesses:

J. M. SMITH, HENRY \VEBER.

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