US 1185119 A
Description (OCR text may contain errors)
H. Ey MARSHALL.
APPLICATION FILED D504.
Patented May 30, 1916.
UNITED sTATEs PATENT onerosi E. MARSHALL, OF HIGHLAND PARK, MICHIGAN.
Specification of Letters Patent.
Patented May 30, l.
Application tiled December 4, i915, Serial No. 84,949.
To all whom t may concern.'
Be it known that lf, HARRY E. MARSHALL, e. citizen of the United States, residing at 'fhland Parli, count)T of Wla'yne, State of lu. Michigan, have invented a certain new and useful Improvement in Linemens Shoes, und declare the following to be a full, clear, and exact description of the same, such as will enable .or-hers skilled in the art to which i; pertains to make end use the same, relie-1T- ence being had to the accompanying drowi ings, which form a part lof this speelication.
invention. relates to shoes for linenien employed in repairingr or Working on lines verrvingg electric current.
"The obje-:ln of the invention is en imuzlatA ing shoe wl ich is constructed to afford o. very high resistance to the passage of eleoourwfnt as for instance, :i resistance. wlnoli will prevent the psssl'ige of a Current il folie and upward.
T noe is constructed in such e Way so five e, visible warning when Worn to e. point where its resistingeflieieney is lowered. The shoe is also constructed in such a way as to prevent the registry of blow-holes in the rubber insulating medium which might easily 'breek down when subjected to smaller eurrents than those for which the shoe is tested.
In the dreWings,-Figure l is e Side elevafion of the shoe. Fig. 2 is o. vertical long'tudinal section of the lower port of the oe. 3 front View of the .lower prt of the shoe with a half of the saine sectioned y I 0, designates the mp which is eonstiueteil preferably of White rubber having high wearing properties. l
.7J is an insulzitingfy sole constructed @refern nbly of brown rubber which has a high electrical-resistance eilieienejf.
o represents e number of layers of waterproof rneterialoustructed of a compound made of scrap, such cork. reclaimed ruhber sind like materials which are ground up and formed into a. compound which is lighter than solid rubber and yetwater proof. The idea of these. layers is only to form aI sort of filler material which is win ternroof and yet lighter than solid rubber.
al represents the fabric on the inside of the sole which lines the. salme.
e designates the heel constructed prefeiw ably of brown rubber.
I It will be noted that the tap extends out in front of the shoe ntthe front so ves to guard as for es possible weer upon the insu loting sole b which is also turned up et the side o the shoe eli the way around es indicated in Fig. l izo afford si'sitehle insulation at the edges.
The upper is constructed of e top portion of waterproof leether which has eyelets thut eye mere perforutions, and the whole shoe kept free from my metallic. devices whatever. leather sit-ring g used to lace the shoes.
The loo portion of the upper eoinprises "uwer :on .71, which extends completely nfil tire shoe and oeoupies the greater elution of the lower portion., and which elle insulated section. The purpose oi' s e' and to insulate this poro@ is not only 'lo gela thicker l renee a., this point buior the very irnnortunt ,object of avoiding the registry of 'bhw/holes in the rubber as'. 'fer es'possible. luesnuie-h as rubber ea Jily breaks down when subjected to electric eurrent at points where there are blowlholesit 'is very' i.. portent. that the likelihood of blowholes he eliminated if possible, and if it cannot wholli7 he eliminated, then protection be affordod :i geinstserious effects from such blowholes. 'l here oceonlplishedby vulcanizingr the two layers of rubber of high electrisel efficiency. nasmuch as the upper serrlion of the lower portion of the shoe is inotfn dangerous Zone, the twoday sin rangement is not continued clear .to thi lop 5 it makes ehe shoe more flexible and easier to walk in to have the upper seotion. of the lower portion thin and flexible'. The inside of the upper is provided with a fabric lining 1.
l; muy be remarked before explaining how all these verts ere fixed together, that the likelihood. of blow-holes allowing the sole to breek down is also oonsiderebhlmini'- mized by the reason of the vulcanizetion of three loyers rubber compounds, the rubber tap C, of high wearing efficiency rubher, the insulating sole l) of high electrical elli eiencj rubber, and the compound c. which is n filler made of scrap material. All these loyers of rubber and fabric are vulcanized ogether by e suitable mlcenizing process, as for instance. by the use of high pressure sind heY j' furnished by steam under pressure. However, l do not limi myself to any pee ticular way of vulcanizing these various lay.
lt is very desirable to guard against inishap in every way possible in preserving life. Consequently l have found it advantageous to construct my shoe olE rubber of such color that it is not likely to be mistaken for other things. For instance, the uppers are constructed of a chocolate colored rubber as is also the heel c, while the, tap is constructed of white rubber compound. lt is especially important that the tap and the insulating sole should be constructed of layers of rub ber of different colors. To this end the insulating sole is constructed of. a chocolate colored rubber, the tap sole being constructed of white rubber compound. W'hen the white top wears away and exposes the insulating sole. a visible warning is immediately given to the user of the shoes or his employer that the danger point has been reached and that either the slice should be repaired or thrown away.
l have found that a shoe constructed in accordance with the above description will stand the test of over 30.000 volts without breaking down. 'lt is obvious that when linernen are provided with these shoes. al-V most a constant precaution against death is secured, as the use of the safety devices is not attendant upon the care of the lineman but on the contrary this insulating medium con stantly attends him and protects him in all cases except where he deliberatelyr takes them od.
In the description and claims l speak of rubber having certain specified characteristics, but it will bc understood that such subn stances are really rubber compounds and suitable rubber compounds lrnoivn as rubber having the specified characteristics can be obtained from any manufacturerlof commercial rubber. inasmuch as cach inanufacturer varies these compounds, the ingredients of each arc not given.
Ordinarily electrical transmission lines .carry 20,000 volts more or less and the material in my shoe is designed to resist such electrical currents without breaking down.
By the use of such terms as high tension electrical currents or similar expressions in the claims I means electrical currents substantially as high as 0,000 volts.
What I claim is:
1. IA linemans shoe. comprising an up.
per andl a sole, the latter having anouter layer of a rubber compound having high wearing properties and an insulating layer of a rubber compound constructed for and capable of resisting high tension electrical currents.
2. A linemans shoe, comprising an upper and a sole secured thereto. comprising an outer layer of one color and thereabove an electrical insulating medium calculated to resist vthe passage of relatively heavy voltage electrical currents, said insulating medium being of a different color so that when the outer layer wears away the danger of wearing away the insulating medium is indicated.
3. A linemans shoe, comprising an upper and a sole, the latter comprising an outer layer of rubber compound of relatively high wearing efficiency and of a specified color, and an ,inner insulating layer constructed of a rubber compound. of a different color and having a relatively high electrical resistance.
fl. A linemans shoe, having an insulating sole and an upper, the lower portion of which is constructed of two layers having llat co` inciding continuous surfaces which are vulcanized together, and which are each oit a rubber compound possessing high electrical resistance properties.
5. A. linemans shoe, having` au electric `insulating sole and an upper, the lower section of the lower portion of which is constructed of two layers or' high elliciency electrical-resistance rubber which are vulca-nized together and the top section o' which lower portion is constructed of a single layer of rubber having a relatively high electrical resistance.
6. A linemans shoe, comprising an upperand a sole, the latter having an outer layer of a rubber compound having high wearing properties, an inner insulating layer of a rubber compound constructed for and capable of resisting high tension electrical currents, and a layer inside of the insulating layer constructed of filler material which is water-proof and lighter than solid rubber compound.
7. A linenians shoe, having a sole and the lower portionvof the upper constructed of rubber including a complete ensheathing of a rubber layer of relatively high electrical current resisting properties.
8. A linemans shoe, having a sole and the lower portion of the upper constructed of rubber, some of which is calculated to resist high voltage currentsthe said Sole v than such first-mentioned layer so that when it wears away the exposure of the inner insulating layer 1s evident.
and which exbafms up at the sides and over- Ries im lapped gmrtions of 'ihe tvc@ high eimrw m "www unizwruls i3 inemmzs. shoe, lxmmg a sole proxdei with a Raye? af material capable of re- ;Qing ihr* high resstancf@ currents used in fslfwz'iafa rzmmirfson lines and an upper whew ms'm" pw'rtm im@ an ensheathng uf mnmix :nimble uf resisting high rabid-Mme zum K f' nf fcz'cal transmission huw. dm mi; Myers wmogencously running iff'ygehei".
la wmmonj: 'whueof sign this speciliration.
H ARY E. MARSHALL.