Patent Abstract:
A connection arrangement for temporary shoring in an excavation site is used to secure I-beams together at corners within the excavation site. Typically, four I-beams are connected together to form a rectangular frame that is suspended within the excavation for bracing the shoring walls thereof. However, any polygonal shape may be used. The connection arrangement includes mating socket or connecting members which are placed over the ends of I-beams to be fastened together. One of the connecting members includes an outwardly extended tab while the other includes a pair of outwardly extended tabs. The first outwardly extending tab fits between the two extending tabs of the corresponding connecting member. All of the tabs are provided with apertures which are placed in alignment when the connection is made so that a bolt or pin can be passed through the apertures to secure adjacent connecting members together. Each connecting member also includes a large eyelet for receiving a chain or other elongated supporting member which is typically used to suspend the resulting I-beam frame at a desired height within the shoring wall. Alternative embodiments provide for a secondary bar attached to the connectors to provide additional support. Also numerous beam/connector arrangements may be provided at different heights within a single excavation site. Such an arrangements provide much greater support for the side walls of the excavation site.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 09/568,856 filed on May 11, 2000, entitled “Corner Connection for Temporary Shoring,” now U.S. Pat. No. 6,416,259. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is generally directed to a system for temporarily shoring up an excavation site. More particularly the invention is directed to a corner connection used in a reinforcing arrangement that supports sheet piling in an excavation site. 
     2. Description of the Prior Art 
     In a typical excavation site, workers are exposed to numerous hazards. The most common hazard is having the walls of the excavation site cave in on the workers, thus causing serious injury. Often due to soil conditions and wetness, the sides of a construction site will simply collapse. Water is a particularly dangerous hazard because it is so heavy and can destroy shoring which has not been properly reinforced. Realizing this problem the government, at both the federal and state level, has set up specific requirements for all excavation sites to avoid the problem of cave-ins. For example the United States Department of Labor and, more specifically, the Occupational Safety and Health Administration (OSHA) requires that excavation sites be prepared with some type of shoring. Additionally many companies are now aware of the problems involved in a typical excavation site and have developed internal policies requiring shoring for any excavations they contract to have completed. 
     A good example of a typical excavation project would be found in replacing underground storage tanks for a gasoline station. Typically, in such an operation, sheet piling is pounded into the ground in a generally rectangular configuration around the work site. The piling has to be driven extremely deeply into the ground and arranged to provide sufficient support against potential cave-ins. Typically the sheet piling has to be driven so that half its total height remains underground after the excavation has been completed. Use of such large amounts of material is quite expensive. After the sheet piling has been installed, the workmen then remove the dirt and fill material from within the rectangular shoring. During the work of removing the old storage tanks and replacing them with new storage tanks the shoring provides protection to the workmen against potential cave-ins. Once the storage tank replacement operation has been completed the shoring can either be completely removed or simply cut down two a safe distance below ground and then left in place. Such a method of shoring an excavation site is extremely expensive. 
     Various solutions have been proposed in an attempt to cut down on the costs of shoring an excavation site. For example U.S. Pat. No. 5,154,541 discloses a modular earth support system. Specifically the patent teaches using panels which are adapted to be placed around an excavation site and interlocked with one another to form a generally rectangular shoring configuration. Once the panels are in place, reinforcing beams are placed behind the panels to ensure the weight and force of the dirt behind the panels does not cause the panels to fail. The main drawback of using such a system is that standard I-beams cannot be used. Rather, special beams which are cut exactly to size and additionally have a customized end configuration must be used. Such beams are particularly expensive, especially considering a large number of beams of varying sizes would have to be kept available for differently sized excavation sites. 
     Another proposed solution to reducing the high cost of shoring excavation sites can be found in U.S. Pat. No. 4,685,837. This patent proposes using panels as shoring members in an excavation site. The panels are reinforced by using laterally extending braces. The braces are connected to one another by a bracket or the braces maybe connected to each other by means of a connection in which one brace has a pair of tabs welded thereto with each tab having an aperture formed therein. The apertures align with a hole in a second brace and a pin is placed though the apertures to complete the connection. In either case there is no provision to adjust the length of the braces and connectors and they must be custom made for each different sized excavation site. 
     Numerous other proposed solutions are available including using wooden shoring which is a custom made to a particular excavation site. Such shoring is used only at the designated site and then disposed of. As a result this approach is prohibitively expensive. Also wooden shoring is not as durable as its metal counterparts. Often water along with regular wear and tear at the construction site can destroy the shoring during the construction job. 
     Based on the above, therefore there exists a need in the prior art of excavation shoring to provide a system wherein shoring can be provided at an excavation site in an inexpensive and reusable manner which does not suffer the disadvantages of the prior art discussed above. More specifically there exists in the in the art to provide a connector for interconnecting various beams used to reinforce shoring in a manner which enables the shoring to be adjusted easily or at least matched readily to the size of different excavation sites and additionally be reusable. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a corner connection for temporary shoring in an excavation site. Specifically, the corner connection is used to secure I-beams together at corners within the excavation site. Typically, four I-beams are connected together to form a rectangular frame that is suspended within the excavation for bracing the shoring walls thereof however, any polygonal shape may be used. The corner connection itself comprises mating socket or connecting members which are placed over the ends of I-beams to be fastened together. 
     One of the connecting members includes an outwardly extended tab while the other includes a pair of outwardly extended tabs. The first outwardly extending tab fits between the two extending tabs of the corresponding connecting member. All of the tabs are provided with apertures which are placed in alignment when the connection is made so that a bolt or pin can be passed through the apertures to secure the two connectors together. The socket members also include a large eyelet for receiving a chain or other elongated supporting member which is typically used to suspend the resulting I-beam frame at a desired height within the shoring wall. Alternative embodiments provide for a secondary bar attached to the connectors to provide additional support. Also numerous beam/connector arrangements may be provided at different heights within a single excavation site. Such an arrangements provide much greater support for the side walls of the excavation site. 
     Additional objects, features and advantages of the present invention will more readily be apparent from the following description of the preferred embodiment thereof, when taken in connection with the drawings wherein like reference numerals refer to correspond parts in the several views. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a prospective view of a corner connection and associated supporting beams for temporary shoring according to a first preferred embodiment of the invention as it would be seen in use in a typical excavation site; 
         FIG. 2  is a perspective view of a corner connection including two corner connectors shown in their engaged condition connecting two reinforcing beams according to the first preferred embodiment of the invention; 
         FIG. 3  is a plan view of a corner connection including two corner connectors shown in their engaged condition according to the first preferred embodiment of the invention; 
         FIG. 4  is a prospective view of a corner connection including two corner connectors shown in their engaged condition according to a second preferred embodiment of the invention; 
         FIG. 5  is a plan view of a corner connection including two corner connectors shown in their engaged condition according to the second preferred embodiment of the invention; and 
         FIG. 6  is a prospective view of a set of three corner connections and associated supporting beams for temporary shoring according to the first preferred embodiment of the invention as it would be seen in use in a typical excavation site. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to  FIG. 1  there is shown a typical excavation site  5  incorporating corner connections  11 - 14  for temporary shoring  18  according to a preferred embodiment of the invention. The temporary shoring  18  actually comprises three major elements: interlocking sheet piling  19 , at least two reinforcing I-beams or wales  20 - 23  and corner connections  11 - 14 , each connection including two connectors for the I-beams  20 - 23 . Interlocking sheet piling  19  is shown placed along the walls of the excavation site  5 . Such interlocking sheet piling  19 , which in the embodiment shown is formed by interconnecting two types of side wall panels and corner panels (not separately labeled), is usually driven into the ground prior to any digging. Typically a driving machine  25 , which is essentially a pile driver, is used to drive each section of piling  19 , which in the embodiment shown is formed by interconnecting two types of side panels and corner panels (not separately labeled), to a desired depth within the ground. As mentioned above, typically such sheet piling  19  was driven two to three times the depth of the excavated hole. In this preferred embodiment however, because of reinforcing structure  26  of the I-beams  20 - 23  and the corner connections  11 - 14 , the sheet piling  19  need only be driven slightly deeper than the desired depth of the excavation hole. In either case the sheet piling  19  is driven into the ground one panel at a time each panel becoming an upstanding wall portion. 
     The panels of piling  19  have interlocking edges and thus can provide support for each other once they are in place. Also the panels are formed in an undulating pattern for added strength. Typically such panels are made of relatively thick and expensive sheet metal. It is important to note that using large quantities of such a sheet metal is extremely expensive. Furthermore, using prior shoring methods, the sheet metal was often left at the excavation site at the conclusion of the construction job. As will be discussed more fully below, with the subject method, the amount of sheet piling used is not only reduced, but less sheet piling is required initially because the sheet piling only has to extend as deep as the excavation hole. 
     The reinforcing structure  26  is provided behind the interlocking sheet piling  19 . The reinforcing structure  26  includes the set of I-beams  20 - 23  which interact with the set of corner connections  11 - 14 . Such a structure  26  is needed in order to prevent the sheet piling  19  from buckling under the weight of the earth surrounding the sheet piling  19 . This is particularly true when the earth is wet or particularly loose. The corner connections  11 - 14  are designed to receive the ends of the I-beams  20 - 23  to form a rectangular structure. While a rectangular shape is shown here and is probably the most common configuration used it should be kept in mind that any polygonal configuration of three or more sides could be used and not depart from the spirit of the invention. The reinforcing structure  26  is then placed along the inside perimeter of the interlocking sheet piling  19 . Under normal conditions the reinforcing structure  26  would simply be suspended by a chain or other mechanism (not shown) at a desired height within the excavation site  5 . If however, the sheet piling  19  starts to buckle under the weight of wet earth it will immediately engage with the reinforcing structure  26 . As pressure is placed on the I beams  20 - 23  and corner connections  11 - 14  they will only give a small distance before applying an enormous normal force which will stop the sheet piling  19  from any further buckling. 
     Turning now to  FIGS. 2 and 3  there is illustrated a close-up view of a corner connection  11  including two meeting connectors  29 ,  30  and the ends of at least two I-beams or wales  20 ,  21 . Each connector  29 ,  30  has a similar overall shape. However, one type of connector  29  has a single tab  32  while the other type of connector  30  has a double tab  34 ,  36 . A single tab type connector  29  shown in  FIG. 2  includes a box-like main body portion  40  having an opening  45  therein for receiving an I-beam  21 . The box-like main body portion  40  comprises five major panels to form the open box shape. Opposing top  50  and bottom  51  panels are connected with opposing side panels  55 ,  56  to form the square or rectangular opening  45  designed to receive the I-beam  21 . An end panel  57  also preferably square or rectangular in shape, closes off one end of the box type main body  40 . These five pieces  50 ,  51 ,  55 ,  56 ,  57  are all made of heavy steel and are welded together. The end panel  57  and one of the side panels  56  has the single tab  32  welded thereto. The tab  32  is a flat plate like member which extends laterally from the box-like main body portion  40  of the connector  29  and has an aperture  60  formed therein. The tab  32  is made of a similar material as the panels of the box-like main body  40 . The tab  32  is preferably welded to the side  56  and end  57  panels. While other methods may be used to attach the tab  32 , it is important that the tab  32  be able to withstand the tremendous hydraulic pressures which may be transmitted by the sheet piling  19  as it starts to buckle. 
     Optionally a gusset  62  is formed between the side panel  56  and the tab  32  for added strength. As seen in  FIG. 3 , an additional gusset  67  may be formed between the tab  32  and the end panel  57 . Preferably an eyelet  69  is formed on the top panel  50 . The eyelet  69  is designed to receive a chain or other elongated supporting member (not shown) used to support the I-beams  20 - 23  and corner connections  11 - 14  at a desired height with the excavation site  5 . The eyelet  69  is completely optional as the chain could simply be placed around one of the I-beams  20 - 23  to provide support. 
     A double tab type connector  30  shown in  FIG. 2  includes a box-like main body portion  70  having an opening  75  therein for receiving an I-beam  20 . The box-like main body portion  70  comprises five major panels to form the open box shape. Opposing top  80  and bottom  81  panel&#39;s are connected with opposing side panels  85 ,  86  to form the square or rectangular opening  75  designed to receive the I-beam  20 . An end panel  87  also preferably square or rectangular in shape closes off one end of the box type main body  70 . These five pieces  80 ,  81 ,  85 ,  86 ,  87  are all made of heavy steel and are welded together. The end panel  87  and one of the side panels  86  has top and bottom tabs  34 ,  36  welded thereto. The tabs  34 ,  36  are flat members which extend laterally from the box-like main body portion  70  of the connector  30  and each have an aperture  90 ,  91  formed therein. The tabs  34 ,  36  are made of a similar material as the panels of the box-like main body  70 . The tabs  34 ,  36  are preferably welded to the side  86  and end  87  panels. While other methods may be used to attach the tabs  34 ,  36  it is important that the tabs  34 ,  36  be able to withstand the tremendous hydraulic pressures which may be transmitted by the sheet piling  19  as it starts to buckle. 
     Optionally a gusset  92  is formed between the side panel  86  and the top tab  34  for added strength. Webs (not shown) may be formed between the two tabs  34 ,  36  in order to further increase their strength. As seen in  FIG. 3  an additional gusset  97  may be formed between the top tab  34  and the end panel  87 . Preferably an eyelet  99  is formed on the top panel  80 . The eyelet  99  is designed to receive a chain or other elongated supporting member (not shown) used to support the I-beams  20 - 23  and corner connections  11 - 14  at a desired height with the excavation site  5 . The eyelet  99  is completely optional as the chain could simply be placed around the I-beams  20 - 23  to provide support. 
     As can clearly be seen in  FIG. 2 , connectors  29 ,  30  may easily be joined together by placing the tab  32  of the single tab connector  29  within the two tabs  34 ,  36  of the double tab connector  30 . Ideally, the single tab aperture  60  aligns with and has substantially the same diameter as the apertures  90 ,  91  formed in each of the two tabs  34 ,  36  of the double tab connector  30 . A securing bolt or pin  100  is placed through the aligned apertures  60 ,  90 ,  91  in order to pivotably secure the connectors  29 ,  30  together. The bolt or pin  100  will support all the forces transmitted between the two connected I-beams  29 ,  30  and therefore must be made of a particularly strong material such as hardened steel. Although shown here as I-beams, beams of different shapes could be used so long as the connector and beam have mating shapes. For example, round, L-shaped and U-shaped beams could be used, as could a beam of almost any cross section. 
     Turning now to  FIGS. 4 and 5 , there is shown a second preferred embodiment of the invention. Specifically, the box like connectors  29 ,  30  of the first embodiment illustrated in  FIGS. 2 and 3  now are shown with modifications to support an added reinforcing member. Since the connectors  29 ′,  30 ′ shown in  FIGS. 4 and 5  are based on the connectors  29 ,  30  shown in  FIGS. 2 and 3  only a discussion of the modifications will be provided here. 
     Essentially each box type connector  29 ′,  30 ′ has a box-like main body  40 ′,  70 ′ that has been lengthened along with its corresponding panels  50 ′,  51 ′,  55 ′,  56 ′,  80 ′,  81 ′,  85 ′,  86 ′ to provide room to support a pair of extra tabs  101 ,  102 ,  103 ,  104  each tab has a aperture  106 ,  107 ,  108 ,  109  formed therein. A reinforcing bar  120  having a tab  130 ,  131  located at each end is provided to reinforce the two box type connectors  29 ′,  30 ′. The tabs  130 ,  131  located at the end of reinforcing bar  120  each have an aperture  140 ,  141  located therein which will cooperate and align with the apertures  101 ,  102 ,  103 ,  104  formed in the tabs  130 ,  131  of each box type connector  29 ′,  30 ′. A pin  150 ,  151  may then be placed in the respective apertures once they are and proper alignment to hold the reinforcing bar  120  in place. Such an arrangement will increase the maximum permissible load that the shoring connection may take before failure. 
     Alternatively, as shown in  FIG. 6 , in order to handle larger loads on the shoring, multiple rectangular I beam/box reinforcing structures  160 ,  170 ,  180  may be placed in a single excavation site  5 . For example the three sets of I-beam/box connectors  160 ,  170 ,  180  shown in  FIG. 6  can handle a much greater load that a single set is capable of handling. Since the three sets of I-beams and connectors are identical they are relatively cheap to obtain. 
     In operation, typically the entire shoring assembly would arrive on a truck. Initially the I-beams  20 - 23  would be arranged in a rectangular or other polygonal shape around the perspective excavation site. Next the connectors  29 ,  30  such as shown in  FIG. 2  are placed on the ends of the I-beams  20 - 23  forming corner connections  11 - 14 . It is important to note that the connectors may simply be slipped onto the ends of the I-beams  20 - 23  and that they do not need to be welded thereto. Essentially the main body portion  40  of the connector  29  is adapted to slidably receive the end of an I beam  21  until it hits an abutment such as the end wall  57 . Of course, any abutment will do so long as it transfers force from the I-beam  21  to the connector  29 . As such, the connections  11 - 14  and I-beams  20 - 23  may be easily assembled on site  5 . Next the apertures in the tabs of each single and double tab connector are aligned and a pin is placed there through. The reinforcing assembly  26  formed of the I-beams  20 - 23  and corner connections  11 - 14  now defines the edge of the excavation site  5 . The sheet piling  19  is driven into the ground around the reinforcing structure  26 . Previously, the sheet piling  19  would have to be driven 2 ft. into the ground for every 1 ft. deep into the ground the excavation site  5  would extend. The cost of using so much sheet piling  19  is extremely expensive. With this new invention the sheet piling  19  need only extend slightly below the bottom of the excavation site  5 . 
     Once a the sheet piling  19  is in place, the dirt and other material within the excavation site&#39;s perimeter is then removed. The reinforcing structure  26  is then lowered to an appropriate height. The reinforcing structure  26  is held at that height by chains which extend to the eyelet on each box connector. It should be noted that the reinforcing structure  25  will not actually be under load until and if the sheet piling  19  starts to buckle under the load of dirt or water located behind a sheet piling  19 . If the sheet piling  19  starts to buckle the corner connections  11 - 14  will take that load and be forced tighter unto their respective I-beams  20 - 23 . Once any tolerance between the I-beams  20 - 23  and corner connections  11 - 14  is taken up the reinforcing structure  26  will then prevent any further movement of the sheet piling  19  and also prevent a cave in. Workers can then move about the excavation site  5  and safely perform whatever task is necessary. For example, the workers could remove old storage tanks (not shown) which may need removing and replace them with a new set of storage tanks (not shown). Additionally, other structures may be formed within the excavation site  5 . For example, a slab of concrete may be poured at the bottom of the excavation site  5  to aid in supporting storage tanks. Additionally, gravel or other fill material may be placed around the tanks as is needed. All the while, the workers will be safe from any potential cave in. 
     Once the excavation site  5  is ready to be refilled, typically a corner sheet of piling  19  is removed so as to enable the workers to remove the corner connections  11 - 14 . Once one set of corner connectors is removed, the rest of the reinforcing structure  26  can easily be removed the excavation site  5  and used again. One of the great benefits of the instant invention is that the I-beams  20 - 23  can be rented instead of purchased. This was not possible with prior reinforcing methods because the ends of the I-beam had to be cut to size or a special connector had to be welded there to. Since most rental places require their equipment be returned in substantially the same condition as they were rented the prior art methods could not use rented I-beams. To recognize the cost savings of the subject invention, one must remember that excavation sites are often different sizes. It becomes extremely expensive to have numerous different sized I-beams which have been purchased and must remain in inventory in case an odd size may be needed. With the new invention, a contractor may simply rent the appropriate sized I-beams and return them when the job is done. 
     Although described with respect to preferred embodiments of the invention, it should be understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. Therefore, the specific embodiments disclosed herein are to be considered illustrative and not restrictive. Instead, the invention is only intended to be limited by the scope of the following claims.

Technology Classification (CPC): 4