Patent Publication Number: US-2006005478-A1

Title: Integral formwork system for the construction of pits for loading ramps

Description:
The present invention concerns an integral formwork system for the construction of pits for loading ramps. Loading ramps are known as equipment used to connect the flatcar of vehicles with the loading platform; in particular, as illustrated more clearly in  FIG. 1 , a loading ramp generically indicated as ( 10 ), is normally composed of a metal platform ( 11 ) on which an extension ( 12 ) is applied, with radial or telescopic articulation.  
      For connection with the flatbed ( 13 ) of the transport vehicle ( 14 ) the ramp ( 10 ) hinged to platform ( 15 ) on the side opposite to the vehicle side ( 14 ) is raised using a hydraulic or mechanical system ( 16 ) and its extension ( 12 ) is extended and connected with the flatbed ( 13 ) of the vehicle ( 14 ) to form an inert connecting surface between the platform and the vehicle that fluctuates with the rise and fall of the vehicle suspension, and that also permits the fork lifts, like that shown as ( 17 ) in  FIG. 2 , to rise directly from the platform onto the vehicle flatbed to unload the merchandise.  
      However, if the vehicle is equipped with a rear tailgate, a problem arises because it is impossible to connect the vehicle flatbed with the platform given the interference created by the tailgate.  
      To overcome this problem generally a second pit ( 18 ) is built under the loading ramp to insert the tailgate ( 19 ) of the vehicle ( 14 ) that is lowered to correct position and placed horizontally while the vehicle ( 14 ) is reversing (see  FIG. 2 ).  
      In this case, the construction of the main pit ( 20 ) for loading ramp ( 10 ) is designed according to the type of loading ramp installed afterwards.  
      As far as the construction of the pits is concerned, traditional type pits exist that are built using formwork that remains included in the cast concrete, or the so-called “prefabricated” pit built with prefabricated building methods. This latter type of pit is illustrated in particular in  FIG. 3A , that shows a basic pit ( 20 ), without the recess underneath to hold the tailgate, and in  FIG. 3B , that shows a pit ( 21 ), with a recess ( 22 ) underneath for the tailgate; both types of pit ( 20 ) ( 21 ) are normally built using formwork that can be removed after the cast concrete has set.  
      The loading ramps to be set in these pits are the so-called “suspended” type: that is they are inserted from above and suspended by their upper edge on the perimeter of the pit that is equipped with a concrete tooth or rim for this purpose; the total ramp height is calculated so that it does not reach the recess underneath for the tailgate.  
      In particular, in order to block the ramp from sinking and to fix it to the edge of the pit, the ramp is equipped with a frame around three sides, generally built with angle iron AN and with the horizontal edge at the bottom (this detail can be seen in  FIG. 3C ). The ramp is inserted and the three sides framed with the angle iron are positioned on the three sides of the pit perimeter with the concrete tooth. Shims SP are inserted under the angle iron to make the upper surface level with the height of the finished flooring surface. At this point plates PI are welded between the angle iron AN and the reinforcing rods TO previously set in the cast concrete, and the floor paving PA is finished by filling the remaining space VA that has been formed. ( FIG. 3C ).  
      However, this assembly system presents numerous defects including those described below.  
      First of all, the space VA always represents a kind of “patching up” of the flooring, and is therefore subject to breaking. It also requires flexible jointing around the perimeter, and this is particularly expensive.  
      Moreover, the laying of reinforcing for each of the overhanging ledges on the sides ( 23 ) (which can be seen particularly in  FIG. 3B ) also contributes to a considerable price increase.  
      In addition, the casting must necessarily be made using plain concrete, whereas the total system requires the application and form dismantling of several recoverable formworks to be able to carry out the casting of several units at a time, plus the application of protruding reinforcing rods in the tooth around the perimeter, an operation that must be performed with great precision by hand.  
      Lastly, the system requires the insertion of the “suspended” ramp and its frame. In addition, the finishing work for paving the flooring needs to be carried out after the ramp insertion, resulting in the inevitable consequences connected with splattering the ramp with the finishing cement and damage to the mechanical ramp parts because of the irrigation necessary during concrete work.  
      Therefore the object of the present invention is to overcome the problems described previously, and in particular, to indicate an integral formwork system for the construction of loading ramp pits that is disposable, with specific construction, lightweight, resistant, and compact in size.  
      Another object of this invention is to provide integral formwork for the construction of loading ramp pits that is possible with a single casting operation from zero level (ground level) as far as the level under the flooring surface, and this too will be made in a single casting operation after laying the reinforcing grid under the flooring.  
      Another object of this invention is that of indicating integral formwork for the construction of loading ramp pits that permits a considerable saving in materials (concrete) and permits the possibility casting the flooring in a single operation beginning at the formwork pit level without the need for connecting structures (such as flexible jointing) that are complicated and/or expensive.  
      These objects can be attained by using integral formwork for the construction of loading ramp pits according to claim  1 , to be used as reference to avoid repetition.  
      Further advantageous technical characteristics are described in the appended claims.  
      The advantage of using formwork according to the invention is that it is possible to mount the loading ramp at a later time after all the “wet work” has been completed, thus preventing any damage from water irrigation that inevitably also wets the mechanical parts of the system.  
      Moreover, in the preferred embodiments, the formwork in question can be composed of decomposable appropriately reinforced sheet metal panels and/or piping and/or sections that can be bolted together in order to minimize transport costs.  
      Lastly, the system according to this invention also permits the construction of the overhanging ledge of the pit without heavy reinforcing rods, and when the work is completed, the overhanging ledges act as the support elements for the ramp and the vehicle positioned on the ramp. 
    
    
      Other advantages and characteristics of this integral formwork for the construction of loading ramp pits will be demonstrated in greater detail in the following description and the illustrations in the figures enclosed, that are provided as examples but that are not in any manner limitative, in which:  
       FIGS. 1 and 2  represent the loading systems for traditional type vehicles;  
       FIGS. 3A and 3B  show two examples of known loading ramp pits;  
       FIG. 3C  shows an example of the fixing system of a loading ramp to the edge of the pit according to the known prior art;  
       FIG. 4  is an exploded view of an integral formwork system for the construction of loading ramp pits according to the present invention;  
       FIG. 5  represents a perspective view of assembled formwork according to this invention;  
       FIG. 6  is the plan view of the formwork shown in the previous illustration according to this invention;  
       FIG. 7  represents a perspective view of a slab at ground level equipped with the construction rods for the assembly of the formwork according to this invention;  
       FIG. 8  represents a view of the finished pit built using the formwork described in the present invention;  
       FIG. 9  represents a perspective view of the formwork according to this invention, equipped with further accessories;  
       FIG. 10  shows a plan view of the formwork for a single loading bay;  
       FIG. 11  represents a plan view of another form built using this formwork according to this invention, both connected to each other;  
       FIG. 12  represents a plan view of a form using this formwork, as an alternative to that shown in  FIG. 11 , according to this invention;  
       FIG. 13  is an intermediate vertical section view of formwork according to this invention;  
       FIGS. 14-17  represent several views in intermediate vertical section of formwork as shown in  FIG. 13  during the various stages of construction;  
       FIG. 18  shows a perspective view of the complete unit that demonstrates the construction sequence of an integral formwork system according to the present invention;  
       FIG. 19  shows an exploded view of an embodiment of the formwork according to the invention as an alternative to that shown in  FIG. 4 . 
    
    
      With special reference to  FIGS. 4-19 , integral formwork for the construction of loading ramp pits according to this invention, is preferably composed of a previous connecting beam AN composed of one or more pipings and/or horizontal metal sections TPR, whose ends are fixed, facing downwards, to two specially shaped sections, preferably open PRA 1 , PRA 2  that define the width of the space VSM for the insertion of the tailgate.  
      Above, or before the mounting of the piping TBR two extension supports are mounted PB 1 , PB 2  on which the loading ramp extension is positioned, in the case where this is flared or radius type.  
      The sections AP 1 , AP 2  are fixed facing upwards on the top and sides of the piping TPR, as well as on the joins where the formwork is united, and also to the front of the buffers PA 1 , PA 2 ; the plates LAT 1 , LAT 2  are fixed further up and on the sides of the buffers finishing preferably on a level with the piping TPR. The sections PRA 1 , PRA 2  and the plates LAT 1 , LAT 2  finish preferably with a part PP 1 , PP 2 , PP 3 , PP 4  folded at the back.  
      The plates LAT 1 , LAT 2  finish preferably in the upper part, with the side LAD 1 , LAD 2  folded backwards, while the parallelepipeds PPP 1 , PPP 2  are fixed inside the plates LAT 1 , LAT  2 .  
      The formwork also includes two side panels FF 1 , FF 2 , with a height approximately the same size as the sections AP 1 , AP 2 , preferably composed of sheet metal plates with reinforcing at the bottom, and with the side preferably turned inwards to the inside of the pit, plus a folded over edge (or an additional fixed section) at the top with the side facing outwards.  
      Two other external side panels are also foreseen FE 1 , FE 2 , preferably terminating at the top and bottom with folded edges facing inside the formwork, and a head TE preferably composed of a metal plate finished at the bottom with a folded edge turned inwards towards the inside of the pit, and at the top with a folded edge or reinforcing section to which one or more piping portions are applied TO 1 , TO 2 , TO 3 . These piping portions are inserted, in comb-style, within other piping portions present on the flatbed of ramp ( 11 ), designed to form the hinge between the head of ramp ( 10 ) and the platform ( 15 ) with the insertion of special rods. One or more strong reinforcing rods ZA are inserted behind the tubing TO 1 , TO 2 , TO 3 .  
      The formwork is also composed of two side plates for the head LLT 1 , LLT 2 , preferably with the edges folded over on all four sides towards the inside of the pit, and at least one reinforced joist TAR 1 , TAR 2 , for each side of the formwork, preferably composed of a brick tiled and/or concrete base, in which one or more extra-adhesion iron rods are inserted in lengthwise direction, bound with right-angle rods, preferably spire-shaped, and in turn, bound at the top by one or more longitudinal rods, positioned at an adequate distance from the base; the total complex is constructed according to well known prefabricated reinforced joist conformation used for flat slab construction, for example. Lastly, there is a central joist TCE whose ends are fixed to two plates PTZ 1 , PTZ 2 , preferably trapezoidal shaped, facing upwards, one or more flanges FL to support the loading ramp raising cylinder, and fixed to the joist TCE, sufficient bolts and/or rivets to bolt all the various parts together through holes drilled for this purpose, and an adequate number of strong reinforcing rods, set in appropriate positions to maintain the formwork in the cement.  
      It should be remembered that the conformation described above can be varied in shape and components to attain the same objective.  
      The integral formwork system according to the invention, assembled and concreted as shown in  FIG. 8 , illustrates all the above-mentioned components connected together, preferably by bolting.  
      One of the most important characteristics of this formwork, illustrated in  FIG. 8 , is represented by the front AN connecting beam that forms the external face of the loading platform, designed to share the weight of the castings between the left and right hand ledge portions AG 1 , AG 2 .  
      Parts AG 1 , AG 2  form an extension that is not supported, given that, below, the opening of the space VSM for the installation of the tailgate is wider than the width of the upper pit FSR, used for the loading ramp installation.  
       FIG. 4  shows that the perimeter of the space for the tailgate is formed by the head TE starting from the front AN connecting beam, moving towards the left, of the external side FE 1  of the head plate LLT 1 , of the head TE, of the head plate LLT 2  and of the external side FE 2  that is reconnected to the front AN section to form the complete perimeter.  
      In preferred but notlimiting embodiments the joist TCE is applied in contact with the lower edge, and below the side panels FF 1 , FF 2 , and is equipped at each end with the two plates PTZ 1 , PTZ 2  that are positioned and fixed at the exterior of the two side panels FF 1 , FF 2 . Moreover, the two plates PTZ 1 , PTZ 2  are folded over at the top towards the exterior, and this provides the configuration for certain adherence in the cast concrete thanks to the simultaneous action of the other elements such as the extra-strong iron rods, for example.  
      In the same way, the perimeter of the pit for the loading ramp FSR is formed as follows: starting from the front connecting beam AN moving towards the left, with the vertical section AP 1  preferably fixed to the AN, the internal side FF 1 , the head TE, and the external side FF 2 , that reconnects with the vertical section AP 2  (preferably integral with AN) and to the front section AN, to close the complete perimeter.  
      As a result it is provided an assembled formwork according to the invention, that is illustrated in detail in  FIGS. 5 and 6  where, in particular, it can be seen that in the side positions there are empty spaces between the external side of the area VSM to house the tailgate FE 1  and the side panel FF 1  of the ramp pit FSR; these empty spaces are covered by at least one reinforced joist TAR 1 , positioned against the plate PTZ 1  and the side panel FF 1 , and supported at each end on the parallelepiped PPP 1  and on the head plate LLT 1  and at the side, on the external wall FE 1 .  
      In a symmetrical position, it is foreseen to install at least one other reinforced joist TAR 2  with the same support systems and with the same characteristics.  
      The assembled formwork has the same height as the finished platform, and this can be obtained either by constructing the elements PRA 1 , FE 1 , LLT 1 , TE, LLT 2 , FE 2 , PRA 2 , to measure at the same height, or by using well known systems that make it possible to adjust the elements to the correct height.  
      The construction sequence of integral formwork according to the invention is basically as follows:  
      First of all, for the pit construction a simple slab is created SOL (see  FIG. 7 ) at ground level TER in which pieces of construction rod TND are arranged so that they protrude for a height of about 1 meter.  
      The formwork is then assembled as described above and as illustrated in  FIG. 5 , and then rods TND are positioned inside on the slab SOL (See  FIG. 6  for easy reference).  
      After this, the metal structure is positioned with precision, and shims are inserted underneath so that the upper edge is level with the flooring surface; then the two prefabricated reinforced joists TAR 1 , TAR 2  are placed on the sides of the structure to contain and form the overhanging side sections.  
      The structure created in the manner described above provides a rapid efficient system with precise measurements and that is perfectly square for forming the tailgate space without the need for any further joists to support the concrete casting.  
      In particular, the use of the prefabricated joists TAR 1 , TAR 2  permits the reduction of the height of the slab at the level of the side overhanging sections AG 1 , AG 2  and consequently a considerable reduction in costs for expensive internal reinforcing.  
      In order to reduce the amount of concrete necessary, to be replaced with inert material that is less expensive, the side and rear casting must be contained by the construction of a simple perimeter wall, with light reinforcing that can be contained within a thickness of only 15 cm, for example.  
      The present invention also provides for this aspect with the use of side forms for concreting CAL  1 , CAL 2 , and rear form CAP 1  shown in  FIG. 9 , preferably at a fixed height 1 meter for example so they can be used to cast the concrete to the most suitable height. As a result, there are various possibilities for application such as single or multiple loading bays for example.  
      In particular, single loading bays can be created at first such as the model shown in  FIG. 10  as an example, where the side forms CAL 1  that can be recovered are marked for identification. These are preferably connected by bolting to the recoverable rear form CAP 1  and the folded over portion PP 1 , PP 2  of the respective elements PRA 1 , PRA 2 .  
      The recoverable forms CAL 1 , CAP 1  are preferably maintained at an established distance from the internal perimeter of the space for the tailgate, from the shims DIS (of a known type) and within this distance they contain the rods TND already positioned in the base slab SOL. The adjacent or close position of the loading bay can make the casting of the formwork more economical, because if the forms are united together this can exclude the side form CAL 1  on the adjacent sides.  
      When the bays are adjacent to each other, the rear form CAP 1  are also bolted together directly, and in this case, the space SPZ between the two ramps is cast in a single operation without the need for installing the form CAP 1  (e.g. see  FIG. 11 ).  
      It should be noted that the formwork described in this invention has been designed preferably with an external measurement of 3.3 meters and a front width of the two lower sections PRA 1 , PRA 2  of 15 centimeters; this is because the resulting exterior creates reinforced perimeter walls, 15 centimeters thick, resulting in a considerable saving in concrete but also guaranteeing the necessary support for the unit even with reinforcing supplied by only a few vertical iron rods.  
      Therefore, this system provides a tailgate space three meters wide (excellent size) with a depth equal to that of the ramp and in any case, no smaller than 2.3 meters (the size that is a little over current minimum measurement requirements, that in any case saves a considerable amount of concrete).  
      Another important characteristic is represented by the fact that the distance of 3.3 meters is basically the minimum space permitted for loading bays for vehicles without rear doors, whereas, vehicles with rear doors require a minimum space of approximately 3.5 meters.  
      Therefore the formwork according to the invention permits the construction of a loading bay with the minimum possible space, by fixing adjacent forms directly together as shown in  FIG. 11 .  
      For the construction of loading bays with a larger space than 3.3 meters, the width of the front connecting beam AN can be varied as shown in  FIG. 12  that shows an alternative system to that shown in  FIG. 11 . A form panel CAP 2  can be interposed in the system in front and at the rear.  
      According to the space required between the loading bays, it is possible to assemble form panels CAP 2  of a larger size, or single bays can be built, as shown in  FIG. 10 , and connected by the front curbing using well-known methods.  
      Once the formwork has been prepared in the required conformation, work proceeds with the preferred method as shown in  FIGS. 13-19 , that illustrate intermediate vertical sections of the formwork, object of this invention, along the central tubing TCE.  
      More in particular,  FIG. 13  shows said formwork section ready for concrete casting, with the perimeter forms CAL 1 , CAL 2 , CAP 1  spaced by using shims DIS.  
      Moreover in  FIG. 13  the final details of the flanges PTZ 1 , PTZ 2  can be seen. These are preferably folded over to follow the reinforcing of the joists TAR 1 , TAR 2 , and in their upper portion, they preferably bear an element with greater grip in the concrete, a rod with improved adherence capacity for example, aimed at a better maintenance of the downward thrust transmitted by the raising cylinder from the ramp to the central joist TCE.  
       FIG. 14  shows said vertical section of the formwork according to this invention with the casting (shown only in the left hand side of the drawing), that is poured preferably up to the upper edge of the forms CAL 1 , CAL 2 , CAP 1 .  
       FIG. 15  shows said section of the formwork with the casting (shown only in the left hand side of the drawing) described in  FIG. 14 ; in the case of  FIG. 15  it shows that the forms CAL 1 , CAL 2 , CAP 1  have been recovered after the concrete has set.  
      On the right hand side of the drawing, CAL 1  and CAP 1  are left visible in position for comparison.  
       FIG. 16  shows the vertical section of the formwork with the previous casting (shown only in the left hand side of the drawing) where the rolled and compacted inert material IRC is piled against the sides and rear; naturally the inert material IRC is piled against the side only if the form is the first or last in the row or if it is a single form, while where adjacent forms are constructed, filling is carried out with concrete only.  
      On the right hand side of the drawing, CAL 1  and CAPI are left visible in position for comparison.  
       FIG. 17  shows the vertical section of the formwork with the casting (shown only in the left hand side of the drawing) and the rolled and compacted inert material IRC; the construction sequence provides for an initial concrete foundation STF in a single operation to cover all the area constructed up to this point around the formwork, including the surrounding layer of rolled and compacted inert material IRC as high as about 8, centimeters under the level of the finished flooring; then during a second stage the standard under-paving grid RET is placed in position, and later still the final floor surface is cast PLC in a single operation and without seams, beginning preferably from the edges FF 1 , TE, FF 2 .  
      On the right hand side of the drawing, CAL 1  and CAP 1  are left visible in position for comparison.  
      With this system it is possible to prevent all the well-known phenomena that lead to pavement surface breaking, caused by castings made at different times.  FIG. 17  also shows the reduced final thickness of the overhanging side portions that, according to the weight, can measure even only 25 cms, instead of the usual 60-80 cms, with an obvious large saving in materials.  
      The overhanging side portions that were extended out from the formwork by being positioned on the elements PPPl, FE 1 , LLT 1  and respectively PPP 2 , FE 2 , LLT 2 , harden after the casting with the reinforcing structure inside, respectively TAR 1 , TAR 2 , and they become not only self-bearing, but also contribute towards bearing the thrust transmitted to the central piping TCE by the raising cylinder of the ramp, transmitted preferably through the flanges FL, by its reaction in the case of safety blocking, and by the fully loaded lift fork that transits the area.  
       FIG. 18  shows a construction sequence of the complete system obtainable using the formwork described in this invention.  
      In particular, the following steps have been emphasised: 
          execution of the pits as shown in  FIG. 7 ;     assembly of the formwork (in the example shown here adjacent) with the vertical reinforcing rods TND positioned in the spaces between the internal perimeter of the formwork and the recoverable external forms;     casting of the perimeter of the first formwork (indicated by A in  FIG. 18 );     rear filling and eventually side filling with rolled and compacted inert material IRC;     casting of the foundation STF up to a height of about 8 cm underneath the flooring surface PLC;     application of the under-flooring grid RET;     casting the flooring surface PLC starting from the angle iron edges of the pit;        

      As well as permitting rapid consecutive casting of the various layers as far as the flooring surface PLC the proposed system also guarantees a uniform surface on the face of the building, eliminating the well-known changes in colour and texture of the concrete caused by the different casting layers, with the obvious advantages regarding function and appearance.  
      This is possible because the external surface remains completely covered by the metal plates of the formwork that remains in position, and that are preferably hot galvanized.  
      This aspect also presents a considerable advantage compared to traditional methods, that, on the contrary, present a further disadvantage in that the vertical sides of the tailgate space are built in plain concrete, easily broken by incorrect or accidental manoeuvring of the tailgate when entering and approaching the platform.  
      In another method, preferable and given as an example, but not limitative (seen in  FIG. 19 ) of the integral formwork according to the invention, the two side joists TAR 1 , TAR 2  are replaced by two plates LOC 1 , LOC 2 , appropriately shaped to be positioned over the elements PPP 1 , FE 1 , LLT 1  and respectively, PPP 2 , FE 2 , LLT 2 .  
      Therefore, the iron rods FSO 1 , FSO 2  are positioned over the plates LOC 1 , LOC 2 , preferably with extra adherence and preformed in “W” shape, of a well recognised type for the formation of reinforced concrete flooring; the iron rods FSO 1 , FSO 2  are long and strong enough to guarantee the bearing of the overhanging portions.  
      These preformed iron rods FSO 1 , FSO 2 , are also preferably equipped on one side with at least one plate PFO, preferably drilled with holes for fixing the rods FSO 1 , FSO 2  to the side panels, respectively FF 1 , FF 2  by normally using bolts that pass through at least one hole FRT envisaged in the flanges PTZ 1 , PTZ 2  and in the side panels FF 1 , FF 2  in order to maintain the rods FSO 1 , FSO 2  at a certain distance from both sides FF 1 , FF 2 , and from each of the plates underneath LOC 1 , LOC 2  in order to surround the rods FSO 1 , FSO 2  completely with concrete to obtain a kind of slab-beam.  
      The distance of each plate LOC 1 , LOC 2  from the preformed rods FSO 1 , FSO 2  is preferably maintained from opposite parts with the edge facing downwards towards the right-angled adjacent joins, with respect to the longitudinal rods below the element FSO 1 , FSO 2  that in this manner will certainly be surrounded by concrete.  
      This further preferred embodiment is mainly aimed at reducing the weight of the prefabricated joists TAR 1 , TAR 2  to a level that can be positioned manually by a single operator.  
      From the description provided, the characteristics of integral formwork of this invention are made very clear, just as all the advantages to be gained with this method.  
      However it is obvious that numerous other variants can be applied to the formwork in question without modifying the innovative principles included in this invention, and it is just as clear that in the practical application of the invention, the materials, form and measurements of the details that are illustrated, can be varied according to the needs, or replaced with others that are technically equivalent.