US 1180729 A
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Description (OCR text may contain errors)
' H. E. MARSHALL.
APPLICATION FILED JULY 8.19X5.
1,180,729. Patented Apr. 25, 1916.
2 SHEETS-SHEET l.
H. E. MARSHALL.
APPLICATION FILED JULY 8. 1915.
. 1 180,729. Patented Apr. 25,1916.
7 2 SHEETS-"SHEET 2.
/H VEN TO]? 4 TTORIIE Y UNITED STATES PATENT OFFICE.
HARRY E. MARSHALL, OF DETROIT, MICHIGAN.
Specification of Letters Patent. 7
Patented Apr. 25, 1916.
Application filed July 8, 1915. 7 Serial No. 38,721.
,eXact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, referencebeing had to the accompanying drawings, which form a part of this specification.
This invention relates to linemens protectors or shields for protecting linemen from wire carrying dangerous currents.
It comprises a shield so t'm'med as to minimize the liability of contact of the wire with the workman and it further comprises what is believed to he a novel form of completely insulated strap and fastener to hold the shield about the wire.
The details of the invention will more fully appear in the specification following.
In the drawings: Figure 1 is a perspective of the top of the pole, the cross arms showing the shield in position. Fig. 2 is aplan View or bottom View of the shield. Fig. 3 is an enlarged cross section of the shield showing in detail the insulated strap. Fig. 4 is a perspective in detail of the insulated strap. Fig. 5 is a sectional detail show ing how the strap may be disengaged from the strap holding means.
The pole is designated a, the two cross bars b b. The shield comprises a body portion 0 which merges into two tubular end we tensions (Z which are of comparatively less diameter than that of the cylindrical body portion a. The whole structure is in effect a split cylinder whose ends are of comparatively small diameter compared with the central or body portion.
The shield is made of heavy rubber or some other eflicient composition for insulating electric currents. By reason of the heavy rubber construction the molded shield parts tend to hold themselves together without the use of straps and rings, but, of course, where human life is in peril, it is absolutely necessary that every precaution be taken to insure perfect insulation. To this end I provide a pair of straps 0. These straps are of peculiar and novel construction. lVhen the shield itself is molded a pair of small bridges f are simultaneously molded on the side of the shield. These are the retaining means for the straps. The straps are made of a material similar to the material of the shield itself. "he strap is molded with a pair of lugs f 7 which have a gradual sloping on one side and have abrupt drops on the other side forming opposed shoulders h it (see Fig. 4). These opposed .-.houlders it h are intended to hold the strap against the bridge. They are so calculated as respects the opening under the bridge that they can be drawn out only with chili .culty. This is shown plainly in Fig. 5, in
fact it is almost impossible to either draw the lugs under the bridge to put the strap in place or to draw the strap out without using Vaseline or other lubricant on the strap so as to make possible easy slippage.
One end of the strap is provided, with an enlargement forming a rectangular 8- shaped frame for the clasp. Thetwo central openings in the frame are square, the
walls of the openings are perpendicular with the exception of the side wall of the end opening which is nearest the extreme end of the strap, this is sloping, as shown in Fig. +i. Likewise one side wall of the opening farther removed from the end of the strap is sloping.
The opposite end of the strap is provided with a pair of lugs g g very similar to the lugs f 7' except that the beveled sides are parallel to each other and the shoulders do not oppose each other. This end of the strap, or what would be called the tongue end, of the strap, can be drawn down through the first opening at the frame end of the strap under the bridge 11 of the rectangular 8 and thence up through the second opening, one or the other lugs y will thereby engage against the bridge- 2', as shown in Fig. 1, depending upon how tight it is desired to draw the strap. The parts will hold themselves in this position, but they are materially aided in this respect by the tendency of the shield to resume a full cylindrical shape after the strap has been drawn about it so as to constrict it, it being apparent that this would tend to enlarge the ring formed by the strap and consequently bring the shoulder of the lug tightly against the bridge 2'. A split rubber ring j can be fitted over each end extension (Z of the shield. This securely holds the end extensions together and prevents contact with the current carrying wire.
Another important improvement in this shield is the way it is molded, so as to prevent any opening of the ends of the body portion of the shield by reason of the pins over which the shield lits. The pins which carry the insulating caps are normally covered by the body portion 0 of the shield. This is the function of the enlarged body portion. but in shields made of llexible. material heretofore constructed the fitting ol' the shield about the pins especially where the shield is used upon a double arm, as shown in Fig. 1, is calculated to spread the shield at the point A', Fig. 2. Serious and fatal accidents have been caused by this exposure. To avoid these defects 1 have. molded the shield so that the parts come together along the lilies l I Fig. 3. That is to say. the parts of the reduced extensions (1 and the opposed parts of the. shield in the. zone where the body portion and the tubular extensions merge also come together but the center of the body portion is provided with cut-in portions which together form a long slotm. This slot in is wide enough to accommodate the pins on the cross arms consequently there is no forcible spreading of the sides of the shield so as to result in a consequent opening of the shield at other places. This opening has heretofore usually taken place at the points 7.: as already indicated due to the spreading of the sides of the shield caused by the insertion of the. pins.
\Yhat I claim is:
l. A linemans shield. having in combination. a body and a strap for engaging about the bodyand provided with a clasp, said strap and clasp constructed of a flexible rubber composition.
2. A line'man's shield. having in combination, a split-tubular flexible body and a strap and clasp for engaging about the split tubular body, said strap and clasp constructed of insulating material, and the clasp parts held in engaged position by'reason of the tendency of the split tube to expand when the strap constricts the same.
3. A linemans shield, having in combination, a split tube of insulating material provided with one or more bridges molded on its side and one or more straps constructed of electric insulating material each having a pair of lugs which can be drawn through the bridge only with difliculty, said lugs serving to retain the strap in relation to the bridge, each of said straps provided with an insulated means for fastening the ends of the strap together.
4. A linemans shield, comprising a body portion provided with strap retaining means on one side and a strap secured to the strap-retaining means and having one end in the form of a figure 8, the other end being provided with one or more lugs for the purpose specified.
A linemans shield, having in combination, a body portion provided with a molded bridge, a strap constructed of insulating material having a pair of lugs with opposed shoulders for engaging the sides of the bridge to hold the strap to the bridge, the said ends of the straps being provided one with an enlargement in the form of a figure 8 and the other with one or more lugs having at one side abrupt shoulders and at the other side sloping faces for the purpose described.
In testimony whereof, I sign this specification.
HARRY E. MARSHALL.