Abstract:
The invention relates to tubular-type scaffoldings, to a method for assembling them and to the horizontal transoms incorporated therein. A scaffolding according to the invention comprises vertical elements bearing sockets on each of which may be fixed one end of a horizontal transom bearing a fork and a conical pin prisoner therein. Near its end, the pin comprises a protruding pivot. At rest, the pin occupies a substantially horizontal position and the upper edge of the socket abuts slightly to the rear of the pivot and causes the pin to pivot to vertical position. One application of the invention is the erection of scaffoldings for the construction of buildings, ships or reservoirs.

Description:
FIELD OF THE INVENTION 
     The present invention relates to tubular-type scaffoldings, to a method for assembly thereof and to the horizontal transoms incorporated in such scaffoldings. 
     The technical sector of the invention is that of the construction of rapidly assembled and dismantled tubular-type scaffoldings. 
     Tubular-type scaffoldings are scaffoldings composed of vertical elements connected together by transoms or horizontal crosspieces and possibly by oblique wind braces. 
     The vertical elements, transoms and wind braces are generally tubes, hence the current name of tubular scaffolding. It is specified that this name is not limiting in character and that the vertical, horizontal or oblique elements may be other than tubes, for example angles or girders in section form. 
     The vertical elements may also be constituted by a vertical wall, for example a metal reservoir wall or a ship&#39;s hull on which the horizontal transoms are fixed. 
     Rapidly assembled and dismantled tubular-type scaffoldings are well known and are currently used as scaffolding in the construction of buildings, ships, reservoirs, for supporting frameworks or for constructing easily dismountable light structures, etc . . . . 
     DESCRIPTION OF THE PRIOR ART 
     Tubular-type scaffoldings are known in which the vertical elements are equipped with hooking elements fixed at determined levels and the horizontal transoms bear at at least one of their ends an assembly piece which is rigidly assembled with a hooking element by a wedge-shaped pin. 
     U.S. Pat. No. 3,817,641 to KWIKFORM Limited describes such scaffoldings in which the vertical elements comprise vertical sockets and the horizontal transoms are equipped at their two ends with a spigot member having two arms which engage on a socket and which comprise slots in which a conical wedge member is manually engaged. 
     French Pat. No. 2 288 199 (75 31319) to E. LAYHER describes tubular scaffoldings comprising vertical elements which are equipped with horizontal flanges bearing openings and horizontal elements which bear, at their ends, shoes which are provided with a horizontal slot which engages on a flange and with two openings in which a conical pin is manually engaged. 
     All known tubular-type scaffoldings comprising a fork-shaped assembly piece and a pin which is driven through slots in the fork present the drawback that a workman must have access to each point of assembly to place the pin in position by hand. This operation requires time and, in addition, it may be dangerous since, during this operation, the horizontal transom is only engaged on a socket without being connected thereto, and the scaffolding is not rigid. 
     A deformation of the scaffolding risks causing the transom to fall and this may injure the workman or even knock him down. 
     SUMMARY OF THE INVENTION 
     It is a first object of the present invention to provide improved scaffoldings wherein the introduction of the pin does not require a workman to have access to each point of connection, but can be automatically obtained by a slight relative displacement in the vertical direction of a transom after the forks located at the end thereof have been engaged around the sockets of the vertical elements. 
     It is a further object of the present invention to procure scaffoldings which comprise assembly sockets enabling a horizontal transom to be fixed in an oblique direction with respect to the vertical plane of symmetry of the sockets, which makes it possible in particular to place horizontal transoms not perpendicular to a flat vertical support in the event of the sockets being fixed to such a support, for example to the wall of a reservoir or to a ship&#39;s hull. 
     It is a further object of the invention to provide scaffoldings in which the sockets fixed to the vertical elements enable oblique wind braces to be fixed. 
     Yet a further object of the invention is to provide scaffoldings comprising pins which may be dismantled with the aid of cables or poles without requiring the effective presence of a workman whose job is to drive in the pins locally. 
     A scaffolding according to the invention is a scaffolding of tubular type which is composed of vertical elements equipped with hollow sockets and with horizontal transoms comprising, at at least one of their two ends, an assembly piece in the form of a fork which comprises a vertical wall and two horizontal flanges each comprising a slot, which fork bears a conical pin imprisoned therein which is engaged through the slot in the upper flange and which occupies a substantially horizontal rest position. 
     The objects of the invention are attained by means of scaffoldings in which each pin comprises a protruding pivot which is located near the narrow end of the pin and which abuts against the lower face of said upper flange and said pin and/or said fork further comprise means for positioning the pin in rest position so that the upper edge of said socket abuts slightly to the rear of said pivot when said fork is engaged on one of said sockets and in abutment thereagainst and means for guiding the descent by gravity of said pin. 
     The method for assembly the scaffoldings according to the invention comprises the following operations: A fork bearing a substantially horizontal pin is engaged on a socket until the vertical wall of the fork abuts against the socket then a relative vertical displacement is made of the transom bearing the fork with respect to the socket which brings the upper edge of the socket in abutment against the lower edge of the pin, slightly to the rear of said pivot and which causes the pin to pivot to the vertical and descend by gravity inside said socket, engaging in the slot in the lower flange. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     According to a preferred embodiment, the lateral faces of the sockets comprise at least one hole for fixing oblique wind braces. This hole is preferably extended by a lateral notch. 
     The widest end of each pin advantageously bears a hole or a slot enabling the pin to be hooked to lift it from a distance. 
     The invention results in novel tubular-type scaffoldings which are rapid to assemble and dismantle. 
     An essential advantage of the scaffoldings according to the invention lies in the fact that the pins for assembling the horizontal transoms on the vertical elements are placed in position without any workman having to have access to the points of assembly to position the pins by hand. This positioning is obtained simply by a relative vertical movement of the transom with respect to the fixing sockets. The general, the mere weight of the transoms suffices to cause the pins to pivot. This firstly results in a considerable saving of time and, in addition, accidents during erection of scaffoldings are reduced. Finally, it becomes possible to position and remove horizontal transoms at places which are of difficult access, by offering them suspended from a cable or by guiding them with poles for engage the forks on the sockets. 
     This result was obtained by modifications of the known pins and assembly pieces enabling the pins to pivot and drop into their housing without any manual intervention on the pins. 
     In particular, the devices for positioning the pins at rest which cause the upper edge of the sockets to abut slightly to the rear of the pivot of the pin are essential for correct functioning as well as the devices which guide the descent of the pin by gravity. 
     Of course, once the whole of the scaffolding according to the invention has been erected, a workman can drive in each pin with a hammer but he can do this in complete safety as the whole scaffolding is rigid and he can work rapidly, passing directly from one pin to the following without any intermediate displacement. 
     This pin blocking operation may be eliminated by vibrating the whole scaffolding, which suffices to block the pins. 
     The scaffoldings according to the invention make it possible to fix horizontal transoms as brackets on a vertical wall. In this application, thanks to the shape of the sockets, they enable brackets to be fixed perpendicularly, obliquely or parallel to the wall. 
     The scaffoldings according to the invention enable oblique wind braces to be fixed directly on the sockets. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The invention will be readily understood on reading the following description with reference to the accompanying drawings, in which: 
     FIG. 1 is a view in elevation and in partial section of the assembly between one end of a horizontal transom and a vertical element. 
     FIG. 2 is a view from the left of the end of the tramsom of FIG. 1. 
     FIGS. 3 to 6 show successive stages of the assembly operation. 
     FIGS. 7 and 8 are plan views of two positions of assembly. 
     FIGS. 9 and 10 are a view in elevation and a view in plan of an assembly comprising an oblique wind brace. 
     FIGS. 11 and 12 are axial sections through one end of a horizontal transom. 
     FIG. 13 is a partial horizontal section through a socket and a pin. 
    
    
     Referring now to the drawings, FIGS. 1 and 2 show an assembly between a vertical element 1 and one end of a horizontal transom 2 of a scaffolding. 
     The vertical elements 1 bear hooking elements 3 in the form of hollow sockets. The sockets 3 are fixed to the vertical elements at determined levels. The sockets 3 are constituted for example by a steel band which is curved and whose two ends are welded to the vertical element 1. At least one of the ends of the horizontal transoms 2 is provided with a hooking element 4 in the form of a fork or stirrup in U form, having two horizontal flanges 4a, 4b connected together by a vertical wall 4c which is welded to one end of the transom 2. The opening of the fork 4 is greater than the height of the sockets 3, with the result that the fork may be engaged on a socket, the flanges 4a and 4b then being placed above and below the socket 3. 
     A fork 4 and a socket 3 are assembled in known manner by means of a wedge-shaped pin 5. To this end, the flanges 4a and 4b each comprise a slot, 6a and 6b respectively, and the pin 5 is engaged vertically through the two slots 6a, 6b and through the hollow socket 3. 
     The rear face of the pin, which is vertical, abuts against the inner face of the socket 3, whilst the front face of the pin abuts against the front ends of the slots 6a and 6b. By forcing the pin downwardly, the socket 3 is clamped between the pin and the vertical wall 4c of the fork. 
     Front or outer faces or ends are understood to mean the faces or ends oriented towards the outside of the transom 2. 
     The length of the slots 6a, 6b is determined as a function of the width and conicity of the pin 5 and as a function of the thickness of the socket 3, to allow clamping of the latter when the pin is forced downwardly. 
     FIG. 1 shows in dashed and dotted lines the position 5&#39; occupied by the pin 5 at rest. It will be seen that the pin is then placed horizontally on the top of the transom 2 and that the pivot occupies a position 8&#39; in abutment against the lower face of the flange 4a. 
     FIG. 1 shows that the upper flange 4a of the fork 4 is located above the upper face of the transom 2, that the slot 6a is extended rearwardly beyond the join between the flange 4a and the wall 4c, so that the rear end 7 of the slot 6a is situated in the vertical wall 4c slightly above the upper face of the transom 2. This arrangement enables the rear part of the pin 5 to rest horizontally or substantially horizontally on the top of the transom 2, whilst the front end is engaged through the slot 6a and is located inside the fork 4. 
     The pin 5 comprises, near its front end, i.e. the narrower end, a pivot 8 which is constituted for example by two projections 8a, 8b located on either side of the lateral faces of the pin. 
     As a variant, the pivot may be constituted by one projection only. 
     FIG. 2 shows that the slot 6a is a narrow slot whose width is only slightly greater than the thickness of the pin 5 and less than the thickness of the projections 8a and 8b. 
     It will also be seen that the slot 6b is a wide slot whose width is clearly greater than the thickness of the projections 8a and 8b which may therefore easily pass through said slot 6b. 
     It will also be seen that the length of the slot 6b, in the direction parallel to the axis of the transom 2, is shorter than the largest width of the pin 5. Thus, the pin is maintained in position firmly since the wider end of the pin cannot pass through the slot 6b and the projections 8a, 8b cannot pass through slot 6a. 
     The projections 8a, 8b perform a section function which is that of a pivot which abuts against the lower face of the upper flange 4a when the upper edge of the socket 3 abuts against the lower face of the pin at rest to the rear of the pivot 8. 
     The thrust which is then exerted on the pin causes it to pivot about pivot 8 and the pin comes into vertical position and descends by gravity inside the socket and slot 6b. This automatic pivoting of the pin is an essential feature of the scaffoldings according to the invention. It enables the scaffoldings to be assembled more quickly. It suffices to engage the two ends of a transom 2 on two sockets 3, then to move the transom slightly downwards for the two pins to be positioned and block the transom sufficiently to assure rigidity of the assemblings. The inherent weight of the transom generally suffices to cause automatic pivoting of the pins. 
     Numerous transoms may thus be assembled without the workmen having to have access each time to the ends thereof to place the pins in position by hand, hence a considerable saving of assembly time and improved safety conditions. 
     The assembly devices according to the invention make it possible to position, then dismantle transoms situated in positions which are inaccessible or dangerous to reach, by means of hoisting apparatus or poles, as will be seen hereinafter. 
     FIGS. 3 to 6 illustrate the various steps of the operation for assembly of one end of a horizontal transom 2 on a vertical element 1. 
     FIG. 3 shows the first step during which the fork 4 is engaged around a socket 3 fixed to the element 1. The narrow end of the pin bearing the pivot 8 is engaged against the lower face of the flange 4a. 
     FIG. 1 clearly shows that the inner height of the fork 4, i.e the distance between the lower face of the upper flange 4a and the upper face of the lower flange 4b is greater than the height of the socket 3, with the result that there is a clearance between the socket and the fork which allows a relative vertical displacement of one with respect to the other. 
     FIG. 4 shows the following step during which the transom 2 is displaced downwardly, so that the upper edge of the socket 3 abuts against the lower face of the pin 5, to the rear of pivot 8, and causes the pin to pivot into vertical position. 
     The fulcrum of the socket 3 against the pin is very close to pivot 8, with the result that a slight vertical displacement suffices to cause the pin to pivot. 
     FIG. 5 shows the following step in which the pin 5 is almost vertical and descends by gravity into the hollow socket 3. 
     FIG. 5 shows the case of the narrow end of the pin 5 abutting against the outer end of the flange 4b which is bent upwardly in front of the slot 6b, to form an oblique ramp against which the pin slides. This ramp guides the pin which engages in the slot 6b and which comes into vertical position as shown in FIG. 6. 
     Correct functioning of an assembly according to the invention is determined by correct positioning and correct guiding of the pin which enables the latter to pivot and drop by gravity into its housing. 
     In addition to the bend 9 of the lower flange 4b forming a ramp which guides the pin towards slot 6b, the assembly pieces of the devices according to the invention comprise means for ensuring correct positioning of the pin 5 at rest. 
     A first means is a shoulder 10, visible in FIG. 5, which abuts at rest against the vertical wall 4c of the fork 4 and which forms a stop preventing the pin from recoiling, so that the pivot 8 is placed in front of the vertical wall of the socket 3. 
     In the embodiments according to FIGS. 1 to 6, the upper flange 4a of the fork 4 comprises a downward right-angled bend 11 which forms a stop against which abuts the front end of the pin at rest. This front stop 11 and the rear stop 10 give the pin 5 a determined rest position such that the fulcrum of the upper edge of the socket 3 against the pin is to the rear of the pivot 8 and a short distance therefrom. The bend 11 also contributes to guiding the pin during its descent as shown in FIG. 5. 
     In this phase, the bend 11 avoids the risk of the pin escaping from the fork 4 by passing through the open end thereof. 
     As a variant, shown in FIG. 11, the pin 5 may comprise a rectangular notch 12 whose width is slightly greater than the thickness of the vertical wall 4c of the fork 4 which fits on the upper edge of this wall located at the rear end of the slot 6a. In this case, the front and rear edges of the notch 12 perform the functions of stop for front and rear positioning of the pin 5 at rest and the bent edge 11 of the upper flange may be eliminated. 
     Of course, other equivalent means may be used for positioning the pin 5 at rest. For example, the rear stop 10 may be replaced by a lateral projection which abuts against the inner face of the vertical wall 4c of the fork 4. 
     FIG. 12 shows another variant in which the transom 2 bears a projection 21 against which the rear end of the pin abuts in rest position. 
     FIGS. 1 to 6 shows an embodiment in which the narrow end of the pin has the form of a bevelled nose delimited by a ramp 13 which forms an obtuse angle with the front edge of the pin. FIG. 5 shows that the ramp 13 abuts against the ramp 9 and slides therealong to guide the pin 5 towards the slot 6b. 
     FIG. 7 is a plan view of one end of a transom 2 cottered on a socket 3 fixed to a vertical element 1. The socket 3 is in the form of a U. It comprises a face 3a for abutment of the pin which is a flat vertical face perpendicular to the axis of the transom 2 and two lateral faces 3b, 3c perpendicular to the bearing face 3a. The socket 3 therefore presents a vertical plane of symmetry PP&#39;. The lateral faces 3a, 3b join the bearing face by curved joins 3d, 3e having a radius of curvature R. 
     Normally, the transom 2 is fixed in the position shown in FIG. 7 where the axis of the transom 2 is parallel to the plane PP&#39;. This position ensures a particularly rigid assembly as the flat face 3a is maintained in abutment against the flat face 4c of the fork 4. 
     In the assembled position, the front ends of the fork 4 are not in contact with the vertical element 1 as shown in FIGS. 7 and 8. This arrangement enables the same forks 4 to be used whatever the tubular or flat form of the vertical elements 1. 
     FIG. 8 shows that the transoms 2 may be fixed to the sockets 3 in an oblique direction with respect to the plane of symmetry PP&#39;, the pin 5 then abutting against the curved inner face of a zone of join 3d, 3e. 
     FIG. 13 is a view to a larger scale of a zone of join 3e or 3d having a radius of curvature R. 
     This Figure shows the bearing edge of the pin 5 which has a thickness E. On condition that R√2≧E, the pin 5 may occupy angular positions covering a sector close to 90°. For such positions to be possible, the width and the depth of the sockets 3 must in addition be sufficiently large with respect to the length of the flanges 4a and 4b for the latter not to abut against the inner faces of the socket. 
     On condition that the width of the lateral walls 3a and 3c of the sockets 3 is at least equal to the half-width of the fork 4, the transoms can be fixed perpendicularly to the plane of symmetry PP&#39; by cottering them against the lateral walls 3b and 3c. 
     FIGS. 9 and 10 show the fixation of an oblique wind brace 14 on a point of assembly of a horizontal transom 2 with a vertical element 1. 
     In this example, the vertical element 1 is a tube which bears groups of four sockets 3 disposed in cruciform manner. 
     The lateral faces of the sockets 3 each bear a hole 15 for fixing a wind brace 14. The wind brace 14 which is for example a tube, comprises at each end two holes for fixation, aligned perpendicularly to the axis. The wind brace is fixed by means of blocking rods 16 which bear a catch 17 at one end. The holes 15 comprise a lateral notch 15a visible in FIG. 9 which serves for the passage of the catch 17. The rod 16 bears a bent handle 18 which makes it possible to rotate the rod to bring the catch 17 behind the inner wall of the socket 3. The rod 16 bears a stop 19. 
     Of course, the rods 16 may be replaced by any other equivalent fixing means. 
     FIGS. 1 to 9 show that the pins 5 comprise, near their wider end, one or more holes 20 which serve to hook the pin with a hook placed at the end of a cable or a hoisting apparatus to lift it from its housing and disconnect the horizontal transom from the vertical element. The holes 20 may be replaced by equivalent means such as slots. These hooking means 20 enable the pins to be removed from a distance, without any workman having to intervene locally.