LOCKING DEVICE FOR MODULAR SCAFFOLDING OR SIMILAR

Abstract: The invention relates to a locking device between ledgers and standards for modular scaffolding or similar. According to the invention, the locking device exhibits a spring catch (2) between the ledger (1) and the standard. Preferably, the catch is arranged on the ledger and secures, in its locked position, the ledger to the standard. The catch can have the form of a bent wire, both ends of which are arranged, at the ledger, in two holes, controlling the springing properties of the catch. Preferably, said catch is made of an erosion-resistant material, such as zinc-coated or stainless spring steel, plastic or some other material suitable for the purpose.

Description: LOCKING DEVICE FOR MODULAR SCAFFOLDING OR SIMILAR FIELD OF THE INVENTION The present invention relates to a locking device for modular scaffolding, such as building site scaffolding, mason's staging or similar, and especially to such a locking device between ledgers and standards, for preventing the components of the modular scaffolding to become disconnected from each other. The locking device is springing and self-locking. BACKGROUND A previously known method for fitting ledgers (horizontal members) to standards (vertical poles) in a modular scaffolding, for example a scaffold, is to utilise e.g. screws and wedges. Such fastening devices, however, do not allow any simple and advantageous way of mounting and disassembling of the modular scaffolds. Another, more advantageous method of the prior art comprises the arrangement of loops or rings on the standards, wherein ledgers are fastened by attaching hooks, provided on the ledger ends, from above into the loops. The mounting is locked by means of a manual locking device. This manual locking device comprises a catch, turned manually towards the standard, the catch thereby becoming fixed in its locked position by means of gravity and the friction occurring between rivet and washer, which hold the catch comprised in the locking device, and thus locks the ledger to the standard. Drawbacks of locking devices according to this technique are due to their design, entailing a risk for corrosive sticking, as the catch is manufactured from an erosion-sensitive material, causing it to become very sluggish or to stick to the rivet and the washer. The present invention relates to an improvement of the known locking devices, wherein the locking of ledgers to standards is made by means of a springing and self-locking locking device. SUMMARY OF THE INVENTION The present invention thus relates to a locking device between ledgers and standards for modular scaffolds or similar. According to the invention, the locking device exhibits a spring catch between the ledger and the standard. Preferably, the catch is provided on the ledger and will, in its locked position, secure the ledger to the standard. The catch may have the shape of a curved wire, both ends of which are arranged at the ledger, in two holes controlling the springing properties of the catch. Preferably, said catch is manufactured from an erosion-resistant material, such as zinc-coated or stainless spring steel, plastic or some other material suitable for the purpose. The invention is defined in the appended claim 1, whereas preferred embodi- ments are stated in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention will be described below with reference to the enclosed drawings, in which Fig. 1 is a side view of one side of a ledger without a catch; Fig. 2 is a side view of one side of the locking device according to the invention, including a ledger and a catch; Fig. 3 is a side view of the other side of the locking device according to the invention, as shown in Fig. 2; Fig. 4 is a side view of the catch according to the invention; Fig. 5 is an end view of the locking device according to the invention, including a ledger and a catch; and Fig. 6 is an end view of the catch according to the invention DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present invention, as mentioned above, relates to a springing and self- locking locking device, arranged between a ledger and a standard in e.g. scaffolding. The locking device comprises a spring catch, preferably arranged at the exterior end of the ledger. Alternatively, the catch may be modified to be arranged on the standard (not shown). Fig. 1 shows a ledger 1 without a catch (2). On the vertical portion 5 of the ledger 1 two holes 3 and 3' and a slot 4 are provided for mounting of the catch as shown in Fig. 2. The holes 3 and 3' are spaced from each other both vertically and horizontally, for controlling the springing properties of the catch 2. In order to facilitate fitting of the catch 2, one of the holes 3 or 3' may be shaped like a slot (not shown). The catch is arranged into said holes 3 and 3 ' in such a manner that a portion 2' of said catch 2 extends through the slot 4, as shown in Figs. 2, 3 and 5. The slot 4 will limit the forward and rearward movement of the catch 2. Said portion 2' of the catch 2 is configured in such a way that the catch can be operated manually between a locking position 4A, which is shown in Figs. 2 and 3, and an open, non-locking position at the end 4B of the slot. The holes 3, 3' are so located that the catch 2 is resiliently pushed forward, towards the standard, in the locking position. When the catch 2 is moved rearwards, past a dead centre, it will instead spring rearwards to be maintained by itself in the open position. The catch is maintained in its mounted position through spring force or by overbending. Figs. 4 and 6 show a side view and an end view, respectively, of said catch 2. When mounting the ledger 1 to the standard, the catch 2 will be in its open or its locked position. In its open position, the hooks 6 and 7 of the ledger lean be hooked, without resistance, into the loops on the standard. The catch is then switched over to its locking position. The protruding tip of the catch 2 will then be placed under the upper loop of the standard, preventing the ledger from being lifted up; thus making it securely locked. Disassembling is performed in reverse order. Assembly can also be performed with the catch in the locking position 4A. The catch will then perform a self-locking function. The lower loop on the standard (not shown), will then push the catch 2 a small distance in the direction towards the vertical portion 5 of the ledger 1, as the ledger is pushed on from above. When the hooks 6 and 7 of the ledger 1 are pushed down into the loops of the standard, the catch 2 will spring back towards the standard, thereby wedging the catch 2 against the lower edge of the upper loop thus performing automatic locking. The above-mentioned open, non-locking position 4B is especially advantageous when dismantling the modular scaffolding, as it enables easy unlocking of the locking device, whereby initially one end and then the other of the ledger 1 are manually unlocked, whereupon the ledger 1 is removed. Preferably, the above catch 2 is made of an erosion-resistant material, such as zinc-coated or stainless steel, plastic or some other material suitable for the purpose.

Claims: CLAIMS 1. Device for locking ledgers to standards in modular scaffolding or similar, characterised by the locking device exhibiting a spring catch (2) between ledger (1) and standard. 2. Locking device according to claim 1, characterised by said catch (2) being arranged on the ledger (1) and securing, in its locked position, the ledger (1) to the standard. 3. Locking device according to claim 2, characterised by the catch (2) having a self-locking position (4 A), causing automatic locking of the ledger (1) to the standard to occur when the catch (2) is in said self-locking position. 4. Locking device according to any one of the preceding claims, characterised by the catch being aπanged so as to be retained in an open, non-locking position (4B). 5. Locking device according to any one of the preceding claims, characterised by said catch (2) consisting of a bent wire. 6. Locking device according to claim 5, characterised by said bent wire being affixed by its two ends in two holes (3, 3'), and being maintained in its mounted position, on a vertical portion (5) of the ledger (1), through spring force or by over- bending. 7. Locking device according to claim 6, characterised by one of said holes (3, 3') being shaped like a slot. 8. Locking device according to claim 6 or claim 7, characterised by said holes (3, 3') being spaced in relation to each other, both vertically and horizontally, thus controlling the springing properties of the catch (2) so as to resiliently push the catch (2) towards the standard in a locking position, and to remain, by itself, in an open position. 9. Locking device according to any one of the preceding claims, characterised by said catch (2) extending through a slot (4) in the vertical portion (5) of the ledger (1). 10. Locking device according to any one of claims 1 to 9, characterised by said catch (2) being made of zinc-coated or stainless spring steel. 11. Locking device according to any one of claims 1 to 9, characterised by said catch (2) being made of plastic.

Inventors: OSKARSSON ULF, OSKARSSON, ULF
Applicants: HAKI AB, OSKARSSON ULF, OSKARSSON, ULF
Application year: 2001
Main classification: E04G7
IPC codes: E04G7