The invention relates to a portable shoring device for securing sidewalls of a trench or excavation, also known in the industry as a trench box. More specifically, the instant invention relates to an adjustable spreader bar to manipulate the distance between opposing panels of the trench box.
The construction industry often desires to employ excavations of various types, such as foundations, trenches, and the like. Where excavations are made in the earth, it is desirable to support the upright sidewalls of the excavation against collapse or to protect a sheltered work space in the event of collapse. Due to unstable soil conditions, improper sloping of an excavation and/or other unaccounted for occurrences, landslides and cave-ins ensue. These natural occurrences have been known to destroy equipment, postpone job completion and, most seriously, injure or kill the workers within the excavation. Consequently, trench excavation is recognized by the Occupational Safety and Health Administration (“OSHA”) as being an extremely hazardous construction operation and it has promulgated regulations directed to the manner in which excavations are created and to the structures used to support the excavations against sidewall collapse.
Current practice in the industry is to place trench boxes inside an excavation site. The trench boxes generally are open at the bottom so that excavation can continue while the boxes are in place and open at the top for easy access by men and machinery and easy removal of excavated materials. The primary structure of a trench box is comprised of opposing side panels that perform a shoring or shielding function by holding the sidewalls of the excavation in place, preventing the sidewalls from collapsing into the trench or hole in the ground created by excavating. Additionally, trench boxes usually have a plurality of bars or beams that transverse the lateral width of the trench box, attaching to opposing trench box panels and reinforcing or supporting the opposing panels, thus providing further protection from sidewall collapse. These support bars are also known as spreader bars as they assist in keeping the panels sufficiently spread apart from each other.
It is often desirable that the width between the opposing panels be changed and/or the angle of opposing planar panel surfaces of the trench box be increased or decreased (from parallel), which can be unsafe and time-consuming, especially when the trench box already is in place within the excavation. In particular, fine adjustments often are desired. More specifically, there is a need to be able to adjust the space and/or angle between the opposing panels of the trench box, particularly when the trench box is being driven into or pulled from the excavation.
Spreader bars currently in use are adjustable in length only in limited ways, such as by use of spreader bars or components thereof that have different fixed lengths, by manipulating angled components of predetermined lengths so as to create an outward extension of the support device, or by use of a hydraulic motor to extend the spreader bar when needed.
For example, U.S. Pat. No. 2,956,409 to Wicke (hereinafter the “'409 patent”) describes an adjustable bracing apparatus for shoring walls where the width of the device is adjusted either by having different, wider lengths of rigid brace or support members between the vertical side panels, or by extending connecting rods outwardly causing internal shafts to slide to accommodate a corresponding extension of said shafts.
Also, U.S. Pat. No. 3,362,168 to Dotlich (hereinafter the “'168 patent”) shows an apparatus for supporting the vertical walls of a trench that includes a hydraulic motor mechanism that maintains the side panels of the apparatus in shoring engagement with the vertical walls being adaptable to trench excavations of different lengths through use of pipe extensions of different lengths.
Notably, the '409 and '168 patents are limited in that neither can be used to push apart and pull together the opposing panels while in use as easily and precisely as the instant invention.
The object of the present invention is to provide adjustable internal support bars or spreader bars to hold apart opposing panels of a trench box used in excavation to prevent the sidewalls of the excavation from collapsing inwardly. More specifically, this invention satisfies the need for a shielding and shoring device that is safe, durable, and easy to use, assemble, move, and disassemble, and that can be adjusted to manipulate the distance and/or the planar angle between opposing panels of the trench box, even when the trench box is in place inside the excavation.
There are several advantages of the instant invention over the prior devices. For example, because of the use of a screw, the spreader bar can easily be retracted thus reducing the width of the space between panels of the trench box, and/or extended, increasing the width, as determined by the operator and as warranted under the circumstances. The present invention also facilitates fine adjustments by allowing the operator to extend or retract the spreader as little or, in conjunction with an incrementally adjustable spreader, by as much as necessary.
To accomplish these objectives, the present invention is directed to a new, infinitely adjustable spreader bar having male and female telescoping pipes, both with openings to receive a locking pin and threaded portion that allow the male telescoping pipe to extend or retract by mechanical engagement of a screw apparatus.
Further features, objectives and advantages of the present invention will become clearer when referring to the following detailed description of the preferred embodiments made with reference to the accompanying drawings in which:
The present invention is directed to a fine, infinitely adjustable, spreader bar 20 used in a trench box 10 for securing sidewalls of an excavation, the spreader bar allowing the opposing panels 12, 13 of the trench box 10 to be manipulated both inwardly and outwardly.
Viewing
Notably, the present invention includes a fine adjustment spreader bar 20 which also is connected between panels 12, 13 by adaptor sockets 14, the same way the finite, incrementally adjustable spreader bar 22 is attached to the opposing panels 12, 13, described above.
It is important to note that the infinitely adjustable spreader bar 20 of the instant preferred design is also subject to adjustment in larger, finite increments in the same manner as the incrementally adjustable spreader bar 22. Additionally and more importantly, the infinitely adjustable spreader bar 20 can also be adjusted in significantly small amounts as described below.
Specifically, with reference to
The second pipe 80 of the infinitely adjustable spreader bar 20 includes first and second opposing ends, 83 and 84, respectively, with a first end 83 being removably attached to adaptor socket 14, which is, in turn, attached to the second opposing panel 13 of the trench box 10. The second end 84 is telescopically fitted with the second end 64 of the first pipe 60. The second pipe 80 also includes a cylindrical adjustment screw portion 30, as shown in
The adjustment screw portion 30 of the second pipe 80 has an outer thread 38 and an elongated, grooved opening or slot 32 therethrough with a length substantially aligned with the longitudinal axis 26 of the telescopically fitted first and second pipes, 60 and 80. The helical direction of the outer thread 38 is in the direction of said longitudinal axis 26. The adjustment screw portion 30, as an adaptor, has a female fitted end 34 that is fixedly attached to an intermediate end 85 of the second pipe 80, forming a female receiving end 36 at the second end 84 of the second pipe 80.
As best seen in
When assembled, the locking pin 41 passes through the sleeve opening 42, the elongated, grooved opening 32 of the second pipe 60, and a selected, indexed opening 62 of the first pipe 80, so that when the sleeve 40 is turned along outer thread 38 of the adjustment screw portion 30 of the second pipe 80, the first pipe 60 is forced by the engagement of the locking pin 41 along the elongated grooved opening 32 to change the extended length of the telescoping pipes 60, 80, and to correspondently adjust the spaced relationship between the opposing panels 12, 13 of the trench box 10 in any length within the length of the grooved opening.
Referring back to
In use, side panels 12, 13 of the trench box 10 are spaced and arranged substantially parallel, and securely fitted at opposite longitudinal ends with both the incrementally finite adjustable spreader bar 22 and the infinitely adjustable spreader bar 20 in a stacked relationship. It is not important which is stacked near the top of the vertical panels or near the bottom. Each spreader bar 20, 22 is pinned to a desired length by selecting the appropriate opening 62, to preferably align panels 12, 13 substantially parallel to each other.
The trench box 10 is then placed in the excavation, where it often is forced below the floor of the excavation by hammering the top of the panels 12, 13 with the bucket of a backhoe. To avoid the ground forcing the panels apart during the hammering step, it is preferred that the bottom of the trench box panels be toed inward. Using the instant invention, the finely adjustable spreader bar 20 can easily and quickly be telescopically adjusted in length by manually turning sleeve 40 in the appropriate rotational direction about the longitudinal axis of the telescopically fitted pipe 60, 80. As previously described, the properly positioned locking pin 41 is forced by a channel wall 49′ of the sleeve engagement channel 49, wherein the locking pin is freely fitted for rotational movement therein, to push or pull the first pipe 60 along the elongated groove opening 32 of the second pipe 80, and thereby change the length of the telescoping pipes, and as a result, the angle of the planar surfaces of the panels 12, 13.
When removing the trench box 10 from the excavation, it is often preferred that the bottom portions of the opposing panels 12, 13 of the trench box 10 are toed outward in like, but opposite fashion, so that the trench box 10 releases its grip on the excavation floor to more easily lift the trench box 10 therefrom. In this case, the sleeve 40 is turned in the opposite rotational direction to change the length of the telescoping pipes 60, 80 as needed.
Although the present invention has been described in connection with the preferred embodiment illustrated in the accompanying figures, other variations and modifications may be apparent to those skilled in the art which come within the scope of the present invention as defined by the claims which follow.
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Number | Date | Country |
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WO 2005106132 | Nov 2005 | WO |