US 3766740 A
A method and assembly for protectively shoring the side walls of a trench. A pair of shoring members are held against opposite trench walls by vertically spaced jacks. A push plate assembly for installing the shoring members is securable to a pair of shoring members and mounts hydraulic rams for urging the shoring members into shoring engagement with the walls, following which the vertically spaced jacks are extended to maintain the shoring engagement. The rams are then retracted and the push plate assembly is removed from the trench to be used to install a further pair of shoring members or to remove a previously installed pair of shoring members.
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Description (OCR text may contain errors)
[ 1 Oct. 23, 1973 United States Patent [1 1 Teegen METHOD AND MEANS FOR SHORTING THE SIDE WALLS 0F TRENCHES TO PREVENT THEIR CAVING IN  lnventor:
Primary Examiner-Dennis L. Taylor Attorney-Max Dressler et al.
Donald R. Teegen, 116 Palm Drive, Barrington, lll. 60010 June 16, 1972 ABSTRACT  Filed:
 Appl. No.: 263,457
A method and assembly for protectively shoring the side walls of a trench. A pair of shoring members are held aga' mst opposite trench walls by vertically spaced jacks. A push plate assembly for installing the shoring members is securable to a pair of shoring members and mounts hydraulic rams for urging the shoring members into shoring engagement with the walls, following which the vertically spaced jacks are extended to maintain the shoring. engagement. The rams are then retracted and the push plate assembly is removed 51/41 A from the trench to be used to install a further pairof shoring members or to remove a previously installed 6 l l 41 A pair of shoring members.
AA 11 44 ll 66 UNITED STATES PATENTS 10/1969 Druml... 8/1967 Ward 11/1971 FOREIGN PATENTS OR APPLICATIONS 10 Claims, 7 Drawing Figures 7/1963 Germany mimenumm 3.76 740 SHEET REF 2 This invention relates to an improved method and means for shoring the vertical side walls of a trench to prevent cave-ins and to protect workmen working at the floor of the trench.
To lay pipelines, it is frequently necessary to dig trenches 10, 20, 30 or more feet in depth. The greater the depth of the trench, the greater the danger of caveins, hence the greater the danger to those workmen who must work at the floor of the trench to install and assemble the pipelines.
Various methods have been proposed inthe past to minimize the dangers of deep trenches to workmen. One such method has been to dig trenches with upwardly and outwardly sloping side walls, thus lessening the tendency of the side walls to cave in and to collapse. This method requires the removal of very substantial amounts of dirt, soil and rock and is therefore a very expensive procedure to follow both in terms of cost and time.
Another method which has been used tominimize the danger attendant the caving in of side walls has been the utilization of inverted, U-shaped cage-like, protective shells for workmen at the floor of a trench. A typical shell has a top and sides, fits at the floor of a trench and is adapted to be dragged along the floor of a trench. It provides a shelter and an area in which workmen may work, and serves as a protective areato which workmen may retreat in the event of a cave-in. Although this method permits the digging of a trench of a minimum widththroughoutthe vertical height of the trench (an advantage), it does not protect against cave-ins. Further, it presents difficulties in the movement of the cage along'thefloor of the trench.
Another method which has been used to prevent cave-ins has been the installation of sheeting, such as wooden sheeting, at opposite side walls and the provision ofbraces to hold the sheeting againstthe side walls. That method requires the fabrication and erection of a shoring assembly along the entire length of a trenchand requires workmen to work in the lower regions of the trench to erect the shoring assembly without protection against cave-ins. 1 I
In accordance with this invention, an improved method and assembly for protecting workmen at the floor of a trench and for preventing the cave-in of trench side walls is provided. The assembly comprises a pair of shoring members which may be temporarily secured to an installation means or push plate assembly for positioning within atr ench and for'extension into protective shoring-engagement with the opposite side walls of a trench. After the shoring members have been properly located and positioned, the push plate assembly may be removed and it is then ready to beused to install a furtherpair of shoring members or to remove, as necessary, previously installed pairs of shoring members. A plurality of spaced pairs of shoring members may be installed along the length of a trench in which work is proceeding at the trench'floor and pairs of the shoring members may be removed as work progresses along the floor of the trench.
Desirably the opposed shoring members each mount at least two vertically spaced pairs of jack means. The jack means are retractable and extensible. When they are in their extended position, they force the shoring members outwardly into firm shoring engagement with the opposed trench walls. Each shoring member mounts a guide channel which extends vertically along the length of the member and which is straddled by each pair of jack means. The push plate assembly comprises a pair of elongate push plates which are adapted to be positioned within the guide channels. The push plates mount at least two vertically spaced hydraulic jacks which in their extended positions bear against the guide channels to urge and hold the shoring members in firm engagement with opposed trench side walls at the shoring members into firm engagement with the trench side walls. Thereafter the shoring member jack means are extended-to maintain the firm engagement and are locked in their extended positions, following which the hydraulic jacks are released and retracted inwardly. The push plate assembly is then released from the shoring members and is elevated and. lifted from the trench. The push plate assembly is then ready to be associated with a further pair of shoring members, either a further pair to be installed or a previously installed pair to be removed from a trench. To' remove a previously installed pair of shoring plates, the push plate assembly is lowered into a trench between the shoring member jacks and the push plates are positioned in the guide channels, the hydraulic jacks are extended outwardlyto maintain the engagement with the trench walls, the shoring members and push plate assembly are secured to each other, the jack means are released and, retracted, the hydraulic jacks are retracted and the assembled shoringmembers and push plate assembly are then lifted out of the trench or'a're moved to a new location inthe'trench.
Shoring' memberassemblies in accordance with this inventionare easily and rapidly set in place and reduce to a minimum the likelihoodof cave-ins and injuryto workmen-at the floorof narrow, deep trenches. The push plate assembly is one which may be used to install and remove a-plurality of pairs ofshoring members. The shoring members lend themselves to a leapfrog method of installation and use. The method and assem bly'of this invention provide a substantially improved, inexpensive and safe means for shoring the side 'walls ofatrench. I l I Furtherobjects, features and advantages of this invention will become apparent from the following description and drawings, ofwhich: i FIG. 1 is a perspective'view of a trenchillustrating a plurality of shoring members made and installed in ac-' cordance with this invention; i
FIG. 2 is a cross-sectional view taken substantially along the line 22 of FIG 1; l
' FIG. 3 is a cross-sectional view taken substantially along the line 3-3 of FIG. 2;
FIG. 4 is a perspective view of one of the shoring members of FIG. 1 and the connected push plate assembly;
FIG. 5 is a schematic side elevational view of separated shoring members and a push plate assembly of this invention; and
FIGS. 6 and 7 are schematic plan views of shoring members and a push plate assembly of this invention.
Referring now to the drawings,a presently preferred embodiment of this invention is seen to include at least one pair of opposed shoring members 10 and a push plate assembly 12. Each pair of shoring members 10 is positioned to confront and engage the side walls W of a trench T, and are held in their opposed, protective shoring positions by a plurality of manually operable jack means such as by mechanical jacks 13.
Preferably a plurality of pairs of shoring members 10 are positioned in a trench in spaced apart, side-by-side relation, with the lower ends of the shoring members spaced several feet above the floor F of the trench (see FIG. 1). The spacing between adjacent pairs of shoring members and the spacing of the lower ends of the shoring members above the floor of the trench does not detract from the shoring and protective capability and functioning of the shoring members 10. The spacing does not permit the use of fewer shoring members for a given length of trench and does provide adequate working room below members 10.
Each shoring member 10 includes an expansive main plate 14 having a main guide channel 16 along its length. Guide channel 16 is welded to the inner face of main plate 14. The inner face of each main plate 14 also mounts spaced channel elements 20, the legs of which are welded to main plate 14.
Channel elements 20 and plates 14 cooperate to mount mechanical jacks l3, and this is best illustrated by FIGS. 3 and 4. As there shown, each mechanical jack 13 comprises a threaded shaft 24 and a sleeve 26 adapted telescopically to receive the threaded shaft. Threaded shaft 24 mounts a wing nut 28 which is adapted to bear against the free end of sleeve 26 thereby to facilitate telescopic movement of the threaded shaft 24 inwardly and outwardly of sleeve 26.
A shaft collar 30 is provided to removably mount each threaded shaft 24. Collar 30 defines an opening to receive one end of the threaded shaft and is suitably welded to main plate 14 and to the web of channel element 20 through which it passes. The threaded shaft 24 is removably retained within the opening defined by collar 30 by a removable pin 31. Sleeve 26 is similarly secured to the opposed main plate 14 by a sleeve collar 32. Like collar 30, collar 32 is welded to main plate 14 and to the associated channel element 20. Sleeve collar 32 and one end of a sleeve 26 are removably secured to each other by a removable pin 34. In the embodiment illustrated in the drawings, three pairs of mechanical jacks 13 are provided for maintaining the shoring members 10 in a spaced apart, shoring relationship. As such there are three pairs of collars 30 and 32 for removably mounting the jacks 13.
Each main plate 14 also mounts a plurality of metal rungs 18 which are welded to the inner face. Rungs 18 serve as steps for the use of workmen to enter and to leave a trench.
Push plate assembly 12 includes a pair of opposed push plates 40 which are proportioned to be received within and to bear against guide channels 16. Opposed push plates 40 mount three vertically spaced jack means, such as hydraulic rams 42. Each hydraulic ram 42 comprises a cylinder 44 and a piston rod 46. Piston rod 46 is movable telescopically inwardly and outwardly of the cylinder 44 in a known manner. Each ram 42 is in the vicinity of a pair of mechanical jacks ,13 which pair generally straddles a ram 42.
One end of cylinder 44 is removably secured to a push plate 40 by a first bracket assembly 48. Bracket assembly 48 is secured to push plate 40 by mounting means such as threaded studs 60 which project from push plate 40. Nuts 62 removably fasten the bracket assembly 48 and push plate 40 to each other. Bracket assembly 48 comprises mounting plate 50 through which studs project, and from which a pair of mounting flanges 52 extend. Mounting flanges 52 secure spaced apart bushing elements 54. The end of the cylinder remove from the piston rod 46 is provided with a mounting sleeve 56 which fits between bushing elements 54. An axle pin 58 secures mounting sleeve 56 to the bracket assembly 48 to provide for the transmission of the thrust of a hydraulic ram 42 from the bracket assembly to push plate 40 and to the associated shoring member 10.
Piston rod 46 is similarly removably secured to a bracket assembly 48. Bracket assembly 48' provides a mounting plate 50', mounting flanges S2 and bushing elements 54'. One end of the piston rod 46 is provided with a mounting sleeve 56'. An axle pin 58" extends through the mounting sleeve 56 and bushings 54'- to secure the piston rod to the bracket assembly 48. Bracket assembly 48' is secured to its confronting push plate 40 by further studs and nuts 60 and 62, respectively, in the manner described in connection with bracket assembly 48.
When a hydraulic ram 42 is operated to extend the piston rod 46, the push plates 40 are thrust outwardly against the guide channels 16 of shoring members 10 to force the expansive outer surfaces of plates 14 into firm, shoring engagement with the side walls W of. a trench. To facilitate smooth outward spreading movement of the push plates 40 by hydraulic rams 4'2, stabilizer assemblies 68 are secured to the push plates 40. Stabilizer assemblies 68 each comprise a guide tube 70 welded at one end to onepush plate 40 and a telescopically received guide rod 72 suitably secured to the opposed push plate. Three such stabilizer assemblies are provided, one adjacent each of the hydraulic rams 42.
Push plate assembly 12 is adapted to be releasably secured to a pair of shoring members 10 and to be low.- ered with members 10 as an assembly into a trench. To that end, a keeper plate 74 and a stop 76 are welded to the lower end of each guide channel 16 (see FIGS. 3 and 4). The lowermostends of push plates 40 'are seated on the stops 76 and are kept from being moved laterally by keeper plate 74. Two pairs of coupler brackets 80 are provided on each main plate 14 adjacent the guide channel 16. Coupler brackets 80 define openings through which removable keeper pins 82 are adapted to pass. With keeper pins 82 in place, as illustrated in FIGS..3 and 4, when hooks H are positioned in lift holes 90, pins 82 and keeper plate 74 will resist inward movement of push plates 40, i.e., movement of push plates 40 laterally out of guide channel 16, and the push plate assembly will be supported against downward movement relative to shoring members 10 by the stops 76.
In FIGS. 2 and 3, a pair of shoring plate members have been illustrated in their trench wall shoring position with mechanical jacks 13 thrust into their shoring positions thereby to maintain and hold the plates 14 in -their spaced apart, protective, shoring engagement with walls W. When the jacks 13 are so positioned, the push plate assembly 12 may be removed.
To remove push plate assembly 12, hooks H are removed from lift holes 90 and are transferred to lift plates 92 welded to the upper ends of push plates 40, and the hooks H elevated sufficiently, as by a crane hoist C, to support the weight of the push plate assembly. Thereafter keeper pins 82 are removed, and the hydraulic rams 42 are operated to retract the piston rods 46 from the outward position of FIG. 6 generally to the inward'position illustrated in FIGS. 5 and 7. Thereafter, push plate assembly 12 may be elevated via hooks H, as by the crane hoist C, from the elevation illustrated in FIG. 3 upwardly to the elevation illustrated in FIG. 5, and upwardly andout of trench T.
The push plate assembly 12 may be reassociated with another pair of shoring members 10 by dropping the push plates 40 into guide channels 16 and by appropriately connecting the push plate assembly 12 via keeper pins 82. The assembled shoring members and push plate assembly may then be lowered into a trench as a unit via hooks H placed in lift holes 90, following which the hydraulic rams 42 are operated to urge and push the plates 14 outwardly and into firm engagement with the opposite walls W of the trench. The jacks 13 are then extended to hold the plates 14 outwardly and to maintain the firm engagement between the trench walls and the plates 14, and the push plate assembly may thereafter be removed inthe manner described.
When a pair of shoring members is to be removed from its shoring engagement with the opposed walls of a trench, ajpush plate assembly 12 is suspended, as from a crane hoist C, by hooks H and by lift plates 92, and is lowered between the vertically spaced pairs of jacks 13 until the lower ends of the push plates 40 are in the vicinity of keeper plates 74. Hydraulic rams 42 are then extendedsufficiently to position push plates 40 in the guide channels 16, after which the push plates are lowered until they seat on stop bars 76. The rams are then extended so that the keeper pins 82 may be inserted in coupler brackets 80, thereby to couple the shoring members and push plate assembly.
Hooks Here then removed from the lift plates 92 and are positioned in lift holes 90 and elevated sufi'iciently to be able to assume the load when the shoring members are moved inwardly. The hydraulic rams 42 are then extended to take up the load which had been applied through the mechanical jacks l3, and the mechanical jacks 13 are released and relieved of the load by unscrewing wing nuts 28. Hydraulic rams 42 then may be retracted to relieve the pressure exerted by the shoring members against trench walls W, following which the assembled shoring plate members 10 and push plate assembly 12 may be removed from the trench, as by lifting it via hooks H and crane hoist C.
The hydraulic rams 42 are provided with hydraulic fluid from a suitable pressure source 102 (FIG. 1) through lines 100. Lines 100 preferably are secured to the inner face of one ofthe push plates 40. Each hydraulic ram 42 may be individually controlled by a suitable valve 101 which is associated with the line 100 cither adjacent the rams 42 or at ground level, such as at compressor 102, or at both locations.
A typical shoring member 10 which has been found to be suitable for use in accordance with this invention incorporates a plate 14 approximately 20 feet by 5 feet in height and width. The plate mounts mechanical jacks 13 which are spaced vertically on 7 foot centers beginning 3 feet from the upper end of the main plate 14. The pairs of mechanical jacks are laterally spaced from each other approximately a distance of about 1% feet.
A push plate assembly 40 in accordance with this in vention may have push plates approximately 18 feet long and hydraulic rams 42 spaced apart on about 7 foot centers, the uppermost of the rams being positioned about 2% feet from the upper end of the associated push plates. 7
The bracket assemblies 48, 48' may have mountin flanges which place the center of the bushing elements 54, 54' approximately 4% inches from the associated mounting plates 50, 50. Where the effective spacing between push plates 40, hence between shoring members 10 is to be increased from, for example, a-trench width of approximately 3 to 3% feet to a trench width of 4% to 5 feet, it is possible to substitute other bracket assemblies 48, 48' having mounting flanges of a greater lateral extent, thereby to avoid the necessity of substituting hydraulic rams having longer effective strokes.
Furthermore, although jacks which extendand retract telescopically have been described, other types of jacks may be used as well, such as, for example, jacks which extend and retract by a scissors action.
The utilization of two or more longitudinally or vertically spaced pairs of jack means, such as mechanical jacks l3, facilitates conforming the shoring members 10 to existing trench walls W. Although the spacing of I the trench walls throughout most of the height of the trench may remain fairly uniform and constant, frequently at the top of a trench the-trench walls flare somewhat outwardly. Upper jacks 13 may therefore push the shoring members 10 outwardly somewhat more than the lower jacks, thereby .to maintain the shoring members in shoring protective engagement with the trench walls throughout the length, regardless of the existence of variations in the width of the trench.
Of course, the plates 14 and longitudinal guide chan f 1 nels 16 are sufficiently flexibleto be able to bend enough to conform to :the extentnecessary to the trench sidewalls. r I
It'has been determined that inatrench of a depth of approximately 25.feet to 35 feet that sharing members 20 feet long will adequately and safely perform their intended protective function. By maintaining the lower ends of the shoring members 2 to, 4 feet above the floor of the trench, sufficient room is provided beneaththe lowermost set of jack members 13 for workmen to install and assemble piping, as is schematically illustrated i Although three, four or more pairs of shoring members may be used and installed in a trench, only one push plate assembly is necessary to install those pairs of shoring members. Desirably, a push plate assembly is used to install one of the pairs of shoring members and may then be used to withdraw a pair of shoring members from an area in which the work at the floor of the trench has been completed. The withdrawn pair of shoring members may then be brought for installation at the next location at which shoring and protection is required. By using the pairs of shoring members in a leapfrog fashion, a minimum number of pairs of shoring members can be used.
It will be apparent from the foregoing that modifications may be made in the embodiments described herein without departing from the spirit and scope of this invention. Accordingly, the scope of this invention is to be considered to be limited only insofar as may be required by the claims.
1. A method of shoring sections of the side walls of a trench comprising the steps of removably mounting and securing a first pair of opposed expansive shoring members with a push plate assembly, together lowering the shoring members and push plate assembly downwardly into a trench to position said shoring members in confronting relation to said walls, extending the shoring members outwardly and into firm shoring engagement with the opposite side walls of a trench by actuating a first pair of vertically spaced jack means mounted on said push plate assembly, extending a second pair of vertically spaced jack means mounted on said shoring members to maintain said firm engagement with said opposite walls thereby to shore a section of the side walls of a trench, releasing said first jack means from said securement with said shoring members and retracting said first jack means to move said push plate assembly out of shoring engagement with said shoring members, lifting the push plate assembly upwardly out of said trench while said second jack means are in their extended positions, then removably mounting and securing a second pair of opposed expansive shoring members with said push plate assembly and then lowering them into said trench adjacent said first pair, and repeating the steps to shore a second adjacent section of the side walls of the trench.
2. A method of shoring the side walls of a trench in accordance with claim 1 wherein each of said vertically spaced second jack means comprises a pair of laterally spaced jack members straddling one of said first jack means at each vertically spaced location and said push plate assembly is lifted upwardly between the pair of laterally spaced jack members.
3. A method of shoring the side walls of a trench in accordance with claim 1, comprising the further steps of lowering the push plate assembly 'into the trench between a further pair of opposed shoring members extended in firm shoring engagement with opposite side walls of said trench, securing the pair of shoring members and the push plate assembly together, extending said first jack means to maintain said firm engagement, releasing said second jack means, retracting said first jack means to retract said shoring members from engagement with the side walls of the trench, and together lifting the shoring members and push plate assembly upwardly out of said trench.
4. A method of shoring the side walls of a trench in accordance with claim 1 wherein said second jack means is extended and released manually, and said first jack means is extended and retracted hydraulically.
5. An assembly for temporarily shoring the side walls of a trench comprising a pair of shoring members each having an expansive surface for hearing against a side wall of a trench, a pair of vertically spaced extensible and retractable jack means connected to said shoring members for holding said shoring members outwardly in spaced apart relation and in firm engagement with opposite side walls of a trench, a push plate assembly releasably secured to shoring members and having a pair of opposed push plate members adapted'to be secured to said shoring members and to bear against said shoring members, a pair of vertically spaced extensible and retractable second jack means mounted on said push plate members for extending said push plate members outwardly with said shoring members to force and hold said expansive surfaces in firm engagement with opposite side walls of said trench as said first jack means are extended and retracted.
6. An assembly in accordance with claim 5 wherein each shoring member mounts a'vertically extending guide channel in which said push plate member is positioned and confined.
7. An assembly in accordance with claim 5 wherein said first jack means comprises a pairof jacks at each said vertical position and wherein each of said'pairs'of first jacks straddle said push plates.
8. An assembly in accordance with claim 5 wherein said second jack means are hydraulically operable jacks and said first jack means are mechanical jacks.
9. An assembly in accordance with claim 5 wherein said first and second jack means extend and retract telescopically. l
10. An assembly in accordancewith claim Sincluding means for releasably connectingsaid shoring members to said push plate assembly to facilitate lowering and elevating said assembly as a unit into and out of a trench and for separating said push plate assembly from I said shoring members so that said push plate assembly trench.