US2393126A - Manhole guard - Google Patents

Description

Jan. l5, 1946. A w, w. sTEvENsoN 2,393,126 MANHOLE GUARD Filed March 24, 1944 Sheet-Sheet l.

WITNEJJES Jan. 15,1946.

W. W. STEVENSON 'MANHOLE GUARD lFiled March 24, 1944 2 sheets-shea 2 Patented Jan. *15, 1946 UNITED STATES OFFICE .MAN-HOLE GUARD Wilbur "W. Stevenson, dIittslmrgh, Pa.

Application March 24, 1944,. Senial.No. j 521,906

9 Claims.

Thefiirvention relatesfto vmanhole guards, by vwhiehis meantsstructures that are placed around amialom/fe street-manholes to .protect ,men working in them. :against .injury y:by articles that may iallintolthe holes, and to v,protect :streettraic `suchia's pedestrians -fand vehicles `ragainst :injury byfreasonfof open manholes.

`:obliect Vof :the 1.1invention :is to provide sa sturdy .manhole iguard iformed of sections which .'mayifreadily .be assembled 'for use-.and disassembledor transportation or for-storing in .za manhole throughoutfthe night, rwhich'swhenf-assembled .forms la .fri-gid structure that :may vbe lfirmly lattached :to La -rnarrlzlole casing to 'i afford itullprotection, nthe guard being :provided :with a fgateWhch-is easilyoperable by workmenrenter- .ing sand deaiving aa, manhole.

V.A ,furthervobiectfis .to .provide ascreenadapted itobeaassociated "these-Itard .for 'closing the top of fthe ...manhole :to .protect workmen ,against 'stoneslor other. missiles that might .enter the top :of'the Lgnardthezscreenbeing .readily closed fand lopenedfbyia workman entering .and leaning the manhole.

',Elhe: preferred embodiment .of my invention risf y:vieuri-being ndioatedbythe A.lines :IV-IV 1- cna-Figs.

1 and 2 Eigfr .anc'elevation :of anv uprghtv-forrn ing a part of the superstructure of theiguard; -Iigf6rv azdet'ailedfvertical sectional viewzof la post "formingipartfof 'za -Igate section, thegplane of View beinglindicatedffby'the line vVI-V-I,..:Fig. l2; and "Figlfl a-planview off'lalscreen adapted tube-asso- 'ciated-"withfthe guardflbase which .is shown nin -dotted lines.

'The 'manhole Ig-uard comprises Jesser-itially 1a base 'I and a superstructure each formed .of a plurality Vof separable 1parts'.adapted to be telescopically assembled. nsitisshown Yin Fig. -1, the base is-fformedof twolilike 5semi-circular sec- `tions, *each including La' semi-circular .lpipe 4 "adapted to-rest on the surface aofrra :street :surrounding -a vmanhole,and a '..semi-circular toe --board 5'whcse Ilowenedgeis welded to the .outside of .pipe 4. One end of pipe 4 is provided with a dowel' pin 6,'AFig. y'1,- Yad'aptedlto bemeceivedby Athe" openend of"th'elike pipe roi the other yse'ction. fAiso, leach-,base sectionis provided v.with .fourssoeketsffl the form' oi short sections of pipe whose lower ends are welded ,to the top faceoi -pipe 4.. Each-ofv lthese sockets I is adapted to re- .ceive fan eupr-ig-htlsection of the superstructure `ot the -lgguard which will .,presently be explained, the `sockets bei-ng `spaced :at equiangu-lar rdis- -tar-iceszof 45 degrees for receiving eight Vuprigihts toro-rm fan octagonal superstructure. l

.For-securely attaching the base of the guard toan annular .casing that for-ms the upper wall of a manholaeachk base section isprovided with mw-ardlyeXtending-lugsl-D vinthe forrn of plates AwhichTa-re' -welded tothe top of circularbpesd, thel lugsbeing spacecl at .equaLinterVaIs whenthe sections of the base .areassernbled As shown .in Fig. 4 azman-hole .casing Il is provided with .a sturdy beltflzbelow .each lug IliJ. lilngaging'A the shank of bolt i2 there is an upwardly extending 'adapter llink-t3 whoselower end-is provided with .-a.keyhole slothav-ingits enlarged end upper- ,most tia-receive the head .of the bolt. 'The upper .end of i3 is,A provided with a horizontally extending ;lange EIA 4having a vverticaloper'ring for receivingthe `smooth `.portion of. a.threadedb1`t t5 `which extends'upwardly through an opening Yformed. in. vl1-ig Il). The .upwardly vprojecting" end of bolt -l5..is-.provided withahand nut `I6 whose lower V-iiace Vengages .the .topoflug Il), irnily to .anchor thebase when all the-nuts l are thus -tig-htened,l

When the ysectionso-f basel are thusattached :to afmanhole casing,jtoe board I5 preventsstones or other missilesI rolling on the street from .entering 'the manhole. To .prevent street surface wate-rviromf-flowing into the manhole, the bottoms of tubes. Lmay be sealed .to the tops of casing -li byfasuitablephstic Acompound as indicated at r`if! Fig. 4, ,and :the .meeting vertical edges of toeaboards f5 may be .sealedlby adhesive tape.

.The :superstructure .comprises eight uprights, 'six-of whichareoi .the saine orm as the upright l2i! .shown in Eig. ,5, 4.and two .of whichthat jform gates fareesimilar :to upright-,T20 but 4diier details that willpresentlybefexfilained Each uplright `210 .comprisesa verticalpost '2l in the vform `ofna, pipe; andan .upwardly inclined beam :22 in theforxn of a pipe whose inner `end is welded to .the-topof post Hand to whose outer endthere is f'welded :a ,downwardly extending pin 2d which may be a.shortLsection..oieJ pipe. Betweenbeam .22 fandipost v2| there `is` a 4sheet metal i'lag 25 .whose Aends areweldedto .theY beam and post. The exposed {facev of this fflag '.maybe paintedred lto,indicate.dang.er, `andlitlniayv be .provided with a cube corner reflector 26 to warn approaching automobilists of the presence of the manhole guard.

One of the gate sections, namely, that shown at 30 in Figs. l and 2, is the same as upright 20 with the exception that the outer end of beam 22 of gate section 30 is provided at its lower side with a short pipe 3| which is welded to the beam. Within the confines of pipe 3i the lower face of beam 22 is Vperforated to receive a vlocking bolt of the other gate `Vsection presently' tobe ex`- plained.

In assembling superstructure 2 upon base I, the lower end of post 2l of gate section 30 is inserted in one of the tubular sockets I of the base. Thereafter, proceeding in a 'clockwise direction as shown in Fig. 1, the six like uprights n 20 are similarly placed successively on the base,

each post of an upright being received by av socket l, and the downwardly extending pin 24 at the outer end of'beam 22 of each upright being telescopically received by the upper end of the tubular post previously positioned.

'Ihe last upright of the structure to be assembled is gate section 35, whose construction will now be explained. As shown in Fig. 2, gate section 35 is formed of a tubular post 36 whose lower end terminates above the top of the toe board of the base so that the gate section may swing outwardly. Beam 3l' of the gate section 35 is provided at its outer end with a long tubular pin 3B which is received by post 2i of the last of uprights 23 to be positioned upon base l. The upper end of ypin 38 is provided with a laterally extending collar 39 which bears upon the top of post 2l in which the pin is inserted, the construction being such that pin 38 lying in post 2l acts as the pintle of a hinge pivotally to support gate section 35.

As shown in Fig. 6, post 36 of gate section 35 is provided with a vertically movable locking bolt 40 which may be tubular in form and which is positioned within and guided by a tube 42 arranged concentrically within post 36 and suitably welded to it at itsupper end. The lower end of locking bolt 40 is provided with a latch 43 which extends through an inverted J-shaped slot 44 formed in the portion of the wall of post 36 that faces the interior of the guard so that latch' 43 may be operated by a workman within the guard and is not readily discernible by anyone outside Aof the guard. When the gate is unlocked, latch l43 lies at the lower end of the longer stem of slot 44; Y

When the two sections of base l vhave been assembled as shown in Figs. 1 and 2 and attached to a casing il of a manhole as shown in Fig. 4, workmen may enter the manhole guard through gate sections 30 and 35 which are then open to their dotted line positions shown in Fig. 1. A workman then swings the gate sections `to their closed position shown in full lines in Fig, 1 and brings bolt 4B of gate section 35 into registry with tube 3l on beam 220i gate section 30. The workman then lifts latch 43 to cause its upper end to engage the opening in the bottom of beam 22of gate section 30 and turns latch 43 so that it Vlies in the shorter portion of slot 44, in which position the' Vgates are locked. The manhole guard then forms a sturdy rigid structure which protects both workmen and pedestrians.

To disassemble the guard itis only necessary to lift the gate sections 30 and 35 and the uprights 20 fromv the sockets 1 of the base, to loosen hand nuts I6 to release adapter links I3 from l 3. A manhole guard comDriSrl their engagement with stud bolts l2, and to separate base sections by moving them laterally from each other. The thus separated parts of the superstructure and base are light and easily handled. Furthermore they are of such relatively small size that at the end of a work day they may be stored in a manhole over night,

An advantage of the guard is that when it is assembled and connected to a manhole casing it forms a .sturdy structure that is capable of withstanding heavy external impactswithout being moved or distorted. Also, the gate sections 3D and 35 have the same external appearance as the uprights 20, and hence are not readily discernible by curious or malicious pedestrians who might tamper with or open the gates.

To protect workmen in a manhole against stones or missiles that may fall or be thrown into the top of a manhole guard, the top of the hole may be protected by a screen of the form shown in Fig. 7. This screen comprises a plate 50 which is provided with a pair of openings 5i adapted'to receive adjacent sockets 1 of base l. To plate 50 there is pivotally connected a-three-part screen having a central section 52 and a pair of outer or Wing sections 53. The central section is formed of a U-shaped rod 54 whose ends are provided with eyes that engage holesin plate 50, and a protecting screen attached to the rod Each wing section 53 is also formed of a U-shapedrod 55 whose ends are provided with eyesfor pivotally mounting it on rod 54, the space within each rod 55 being provided with aprotecting screen.

When the screen is assembled with the manhole guard its wings 53 are folded upon central section 52 and the latter is swung upwardly to a side of the guard. The last workman to enter a manhole pulls the screen down after him, and, reaching over the sides of the screen, swings wings 53 to their horizontal position. The central por-V tion of the screen is held in its horizontal position by its engagement with the tops of 4hand nuts i6, and wings 53 may be held in their horizontal i positions by lugs 56 attached to and extending inwardly from tubes 4 of base I. 'When workmen leave a manhole, the screen may readily be opened by rst folding wings 53 upon central section 52, and then swinging the latter upwardly.

According to the provisions of the patent statutes, I have explained the principle and operation of my invention, and have illustrated and described what I now consider to be the best embodiment ot. it. However, I desire to have it understood that, within the sco-pe of the appended claims, the invention may be practiced otherwise than specifically illustrated and described.

I claim:

l. A manhole guard comprising a continuous base formed of a plurality of separable parts, directly connected to each other, and a plurality of separable uprights removably supported by the base and removably connected directly to each other to form an enclosure, lat least one of said uprights being pivotally mounted to' form a gate.

2. A manhole guard'comprising a base formed of a pairV of like separable parts telescopica-ily assemblable with each other to form a continuous support, and a superstructure comprising a plurality of separable uprights removably supported by the base and removably connected directly to each other to form an enclosure,at least one of said uprghts being pivotally mounted to forma gate i Y gY a base formed ofr .a pair of telescopically assemblable'sectioris each comprising a pipe of semi-circular, shape and a semi-circular toe board attached to the pipe, and a plurality of separable uprights removably supported by the base and removably con nected to each other to form an enclosure, at least one of said uprights being pivotally mounted to form a gate.

4. A manhole guard comprising a continuous base formed of a plurality of separable parts directly connected to each other and provided with vertically disposed sockets, and a plurality of uprights each including a post adapted to be telescopically received by one of said sockets, each of said uprights being detachably connected directly to an adjacent upright, and at least one of said uprights being pivotally mounted to form a gate.

5. A manhole guard comprising a base formed of a plurality of separable parts provided with vertically disposed sockets, and a plurality of uprights each including a post whose lower end is telescopically positioned in one of said sockets, each upright including an upwardly inclined beam having a pin at its outer end telescopically positioned in the post of an adjacent upright, and a gate section pivotally supported by one of said uprights.

6. A manhole guard comprising a base formed of a plurality of separable parts provided with vertically disposed sockets, a plurality o1' uprights each formed of a tubular post 'whose lower end is telescopically positioned in one of said sockets and of an upwardly inclined tubular beam having a pin in its outer end telescopically posid tioned in the post o! an adjacent upright, and a gate section pivotally supported by one of said uprights. i

7. A manhole guard comprising a base formed of a plurality of separable parts provided with vertically disposed sockets, a plurality of uprights each formed of a tubular post whose lower end is telescopically positioned in one of said sockets and of an upwardly inclined tubular beam having a pin in its outer end telescopically positioned in the post of an adjacent upright, and a gate section formed of a tubular post and an upwardly inclined beam having at its outer end a downwardly extending pin telescopically received by the tubular post of an adjacent upright for pivotally supporting the gate section.

8. A manhole guard comprising a base, a superstructure connected to the base, and a screen within the base :for covering a manhole, said screen comprising a plate detachably connected to said base, a centrally disposed screen section pivotally attached to said plate, and wing screen sections pivotally attached to the sides of said central section.

9. A manhole guard comprising a base, a superstructure formed of a plurality of uprights detachably connected to the base; and a screen within the base formed of a plate detachably connected to said base, a central screen section pivotally attached to said plate, and wing screen sec tions respectively pivotally attached to the sides of said central section.

WILBUR W. STEVENSON.

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