Clamp fitment for connecting pipe sections

Abstract: A clamp fitment includes a pair of holding members H1, H2 each capable of clamping a pipe section P1, P2, a coupler 6 mounted between both the holding members H1, H2 for relatively rotatably but unseparatably coupling the holding members H1, H2, and a lock mechanism L mounted between both the holding members H1, H2 for restraining the relative rotation of the holding members at any time in positions in which the pipe sections P1, P2 clamped in the holding members intersect each other at right angles. The single clamp fitment for connecting the pipe sections can be used properly as either a "swivel type" in which the angle of intersection of the pipe sections can be freely selected or an "orthogonal type" for unifying the pipe sections in a square fashion. This eliminates the need for a worker to carry two kinds of clamp fitments to a working field, leading to simplified handling and management of the clamp fitment.

Description: The present invention relates to a clamp fitment used for interconnecting pipe sections, such as in a scaffolding framework. Conventional clamp fitments of the type described above include, for example, a so-called "swivel type" clamp fitment designed to relatively rotatably and unseparatably couple a pair of holding members H 1 and H 2 capable of clamping pipe sections P 1 and P 2 , so that the angle of intersection of the pipe sections P 1 and P 2 clamped by the holding members H 1 and H 2 can be freely selected, as shown in Fig.9; and a so-called "orthogonal or square type" clamp fitment designed to integrally couple a pair of holding members H 1 and H 2 by a plurality of rivets or the like at positions in which the pipe sections P 1 and P 2 clamped into the holding members H 1 and H 2 intersect each other at right angles, so that the angle of intersection of the pipe sections P 1 and P 2 is fixed at right angles. The "swivel type" clamp fitment is effective when a pair of pipe sections are interconnected obliquely at arbitrary intersection angle, while the "orthogonal type" clamp fitment is effective when a pair of pipe sections are strongly interconnected orthogonaly. In practice, different types of clamp fitments must be used depending upon the site of the scaffolding framework and for this reason, it is a conventional practice for workers to carry both types of clamp fitments, and use those fitments properly as required, resulting in troublesome handling and management. In view of the above problems it is advantageous to provide a clamp fitment for connecting pipe sections, wherein a common single clamp fitment can be used as both a "swivel type" and an "orthogonal type", thereby overcoming the above-described problems associated with the prior art. FR-A-1103392 discloses a clamp fitment comprising two pairs of clamping jaws which are interconnected by a swivel coupling. When the jaws are not clamped over respective pipes the coupling allows rotation of one pair of jaws relative to the other, but when the jaws are tightened onto respective pipes, frictional engagement occurs between the sliding surfaces of the coupling, which resists relative rotation. If a high torsional loading is applied to the loading the frictional engagement can be overcome, causing one set of jaws to slip relative to the other. US-A-1706215 discloses a similar clamp fitment in which relative rotation between respective pairs of clamping jaws is fixed by means of a bolt which can be tightened independently of whether the pairs of jaws are tightened onto respective scaffolding pipes. According to the present invention, there is provided a clamp fitment for connecting pipe sections comprising: a pair of holding members each capable of clamping a pipe section; a coupler mounted between both said holding members for relatively rotatably but unseparatably coupling said holding members; and a lock mechanism mounted between both said holding members for restricting the relative position of the holding members; wherein in a condition in which said pipe sections are not mounted, said lock mechanism is capable of assuming a state permitting free relative rotation between both the holding members; characterized in that the lock mechanism comprises a fastening rotatably supported on a base frame of one of the holding members and engaging means provided on a base frame of the other of the holding members, the fastening and the engaging means being engagable with each other only when the holding members are oriented such that the pipe sections, when clamped in the respective holding members, are at right angles to one another. With the above arrangement, the clamp fitment can be used as a so-called "orthogonal type" in which the holding members are unified in positions in which the pipe sections intersect each other at right angles in a locking state of the lock mechanism, and as a so-called "swivel type" in which the holding members are connected relatively rotatably in an unlocked state of the lock mechanism. Therefore, the single clamp fitment can be used as either an "orthogonal type" or a "swivel type". This eliminates the need for workers to carry two types of clamp fitments to a work site, leading to strikingly simplified handling and management of clamp fitments. Moreover, only a single type of clamp fitment needs to be manufactured, which contributes to a corresponding reduction in manufacturing cost. Furthermore, because the fastening can only be held in engagement with the engaging means by one of the pipe sections when the pipe sections are fastened at right angles, it is a simple matter for a worker to establish when the pipe sections are at right angles. Consequently the worker can easily assemble the clamp fitment into an "orthogonal type" orientation without having to measure the angle of alignment of the pipe sections. For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:- Fig. 1 is a perspective view of a clamp fitment according to a first embodiment of the present invention; Fig. 2 is a sectional view taken along a line 2-2 in Fig. 1; Fig. 3 is a sectional view taken along a line 3-3 in Fig. 1; Fig. 4 is a perspective view of a clamp fitment according to a second embodiment of the invention; Fig. 5 is a perspective view of a clamp fitment according to a third embodiment of the invention; Fig. 6 is a perspective view of a clamp fitment according to a fourth embodiment of the invention; Fig. 7 is a sectional view taken along a line 7-7 in Fig. 6; Fig. 8 is a sectional view taken along a line 8-8 in Fig. 6; Fig. 9 is a perspective view of a prior art swivel type clamp fitment; and Fig. 10 is a perspective view of a prior art orthogonal type clamp fitment. A first embodiment of the invention will now be described in connection with Figs.1 to 3. A clamp fitment C for interconnecting a pair of pipe sections P 1 and P 2 intersecting each other to form a scaffolding framework is comprised of first and second holding members H 1 and H 2 capable of clamping the pipe sections P 1 and P 2 , respectively. The first holding member H 1 includes a base frame 1 having an arcuate receiving surface la which is capable of abutting against an outer peripheral surface of the first pipe section P 1 , and a tip frame 2 pivotally supported by a pin 9 at one end of the base frame 1 for swinging movement for opening and closing. The tip frame 2 is formed with an arcuate pressing surface 2a for clamping and fixing the first pipe section P 1 by cooperation with the receiving surface la of the base frame 1. A supporting frame portion 1b having a substantially U-shaped cross section is integrally provided at the other end of the base frame 1 to project therefrom. A support stub 3 is laterally spanned between a pair of opposed sidewalls of the supporting frame portion 1b, and an eyeball-like head 4h of a bolt 4 is rotatably supported in a fitted manner by the support stub 3. At a free end of the tip frame 2, there are formed a cutout portion 2g into which a threaded shank 4j of the bolt 4 can be fitted, and a receiving seat 2s for receiving a nut 5 threadedly engaged over the threaded shank 4j on opposite sides of the cutout portion 2g. Thus, the first pipe section P 1 can be clamped between the receiving surface 1a and the pressing surface 2a by tightening and pressing the nut 5 against the receiving seat 2s in a condition in which the threaded shank 4j of the bolt 4 has been fitted into the cutout portion 2g. The structure of the second holding member H 2 is basically the same as that of the first holding member H 1 and hence, the description thereof is omitted, but individual components thereof are designated by reference characters similar to those of the first holding member H 1 . A coupling structure between both the holding members H 1 and H 2 will be described below. Flat intermediate walls 1m of the base frames 1 of the holding members H 1 and H 2 are placed on each other and interconnected for rotation about an axis perpendicular to axes of the pipe sections P 1 and P 2 by a cylindrical coupler 6 penetrating the intermediate walls 1m. The coupler 6 is integrally provided at opposite ends thereof with slip-out preventing outward-directed flange portions 6f each adapted to engage an inner surface of the intermediate wall 1m of the corresponding base frame 1. This ensures that both the base frames 1 cannot be separated from each other in an axial direction of the coupler 6. The above-described structure is similar to that of the conventionally known "swivel type" clamp fitment, but according to the invention, two sets of lock mechanisms L, L are added for restraining the relative rotation of the holding members H 1 and H 2 in a position of intersection of the pair of pipe sections P 1 and P 2 at any time. Each of the lock mechanisms L is comprised of a frame type fastening 7 having a substantially U-shaped cross section and rotatably supported on the supporting frame portion 1b of one of the base frames 1 through the support stub 3, and a notch-like engage recess 8 provided in the arcuate receiving surface 1a of the other base frame 1, such that a locking piece 7a integrally and projectingly provided at a free end of the fastening 7 can be engaged into and disengaged from the engage recess 8. The fastening 7 is movable between an engaged position (shown by a solid line in Fig.2) in which the locking piece 7a is engaged into the engage recess 8, and a disengaged position (shown by a dashed line in Fig.2) in which the engagement of the locking piece 7a is released. If the fastening 7 is turned from the disengaged position to the engaged position, particularly in a condition in which the pipe sections P 1 and P 2 are not mounted to the holding members H 1 and H 2 , and center axes of the arcuate receiving surfaces 1a of the holding members H 1 and H 2 are perpendicular to each other, the holding members H 1 and H 2 are prevented from being rotated by the engagement between the locking piece 7a and the engage recess 8. Therefore, the clamp fitment C serves as an "orthogonal type". A pair of the engage recesses 8 are disposed in opposed locations on the arcuate receiving surface la of the base frame 1 on opposite sides of the axis of the coupler 6, and hence, even in positions of the holding members H 1 and H 2 rotated further through 180 degree from their states shown in Fig.1, the locking piece 7a of each fastening 7 can be brought into engagement with the other engage recess 8 to prevent the holding members H 1 and H 2 from being rotated. Even by this arrangement, the clamp fitment C serves as an "orthogonal type". The operation of this embodiment will be described below. If the clamp fitment C is used as a "swivel type", it is only necessary to place each of the fastenings 7 at the above-described disengaged position. This ensures that the holding members H 1 and H 2 are rotatable about the coupler 6, and only by clamping the pipe sections P 1 and P 2 to the holding members H 1 and H 2 , the pipe sections P 1 and P 2 can be interconnected at any desired intersection angle. On the other hand, if the clamp fitment C is used as an "orthogonal type", the holding members H 1 and H 2 are placed at positions of intersection of the center axes of their arcuate receiving surfaces la, before the pipe sections P 1 and P 2 are clamped. In this condition, the fastening 7 is turned from the disengaged position to the engaged position, so that the locking piece 7a of the fastening 7 is engaged into corresponding one of the engage recesses 8. Thereafter, if the pipe sections P 1 and P 2 are clamped into the holding members H 1 and H 2 , the outer peripheral surfaces of the pipe sections P 1 and P 2 are closely opposed to the outer surfaces of the corresponding locking pieces 7a, so that each of the pipe sections P 1 and P 2 serves to prevent rotation of the locking piece 7a in its disengaging direction. Thus, as long as the pipe sections P 1 and P 2 are clamped in the holding members H 1 and H 2 , the engaged state between the locking piece 7a and the engage recess 8 can reliably be maintained by the pipe sections P 1 and P 2 themselves. In this manner, the relative rotation of the holding members H 1 and H 2 is reliably restrained in the position in which the pipe sections P 1 and P 2 intersect each other at right angles and therefore, the clamp fitment C serves as an "orthogonal type", so that the pair of pipe sections P 1 and P 2 can be integrally coupled to each other at right angles. Moreover, in this "orthogonal" mode, the holding members H 1 and H 2 are coupled to each other not only through the coupler 6 but also through the two fastenings 7 and hence, the breaking strength of the clamp fitment C is correspondingly increased. Even if the fastening 7 should be broken by the action of an excessive shear load between the holding members H 1 and H 2 as a result of the pipe sections P 1 and P 2 being twisted strongly in use, the holding members H 1 and H 2 are still in their rotatably connected states through the coupler 6. Therefore, as in the conventional "swivel type " clamp fitment, there is no fear that the pipe sections P 1 and P 2 are separated from each other. The single clamp fitment C can be used properly as either a "Swivel type" or an "orthogonal type" and therefore, the need for the workers to carry two kinds of clamp fitments to a work site in order to assemble a scaffolding framework is eliminated, leading to an improved handling of the clamp fitment or the like. A second embodiment of the invention is shown in Fig.4. This embodiment is different from the previously described embodiment only in that a fastening 7 is mounted only on one holding member H 2 and no fastening is mounted on the other holding member H 1 . Further, a third embodiment of the invention is shown in Fig.5. This embodiment is different from the second embodiment only in that the engage recess 8 is omitted from the holding member H 2 having the fastening 7 mounted thereon. Yet further, a fourth embodiment of the invention is shown in Figs.6 to 8. This embodiment is different from the third embodiment only in respect of the structure of a lock mechanism. More specifically, in a lock mechanism L' in the fourth embodiment, the locking piece 7a is not provided on a fastening 7'. In place of the locking piece 7a, a pair of locking projections 8' are integrally and projectingly provided on the arcuate receiving surface 1a of the other holding member H 2 , and either one is capable of being brought into engagement with an inner surface of the fastening 7' to prevent the holding members H 1 and H 2 from being rotated. Each of the projections 8' is formed by cutting or notching two portions of the arcuate receiving surface la and bending a portion thereof between the two notched portions outwardly. Moreover, the locking projections 8' are disposed at opposed positions on the arcuate receiving surface la on opposite sides of the axis of the coupler 6. Thus, even in positions of the holding members H 1 and H 2 relatively rotated further through 180 degree from their states shown in Fig.6, the inner surface of the fastening 7' can be brought into engagement with the other locking projection 8' to prevent the holding members H 1 and H 2 from being rotated. Even in this embodiment, an effect similar to that in the previous embodiments can be provided. Alternatively, in the fourth embodiment, two sets of lock mechanisms L' may be provided, as the lock mechanisms L in the first embodiment. Even when only one set of the lock mechanism is provided in the fourth embodiment, the locking projection 8' may be, of course, formed also on the holding member H 2 having the fastening mounted thereon, as in the second embodiment.

Claims: A clamp fitment for connecting pipe sections comprising: a pair of holding members (H1, H2) each capable of clamping a pipe section (P1, P2); a coupler (6) mounted between both said holding members (H1, H2) for relatively rotatably but unseparatably coupling said holding members; and a lock mechanism (L; L') mounted between both said holding members (H1, H2) for restricting the relative position of the holding members; wherein in a condition in which said pipe sections (P1, P2) are not mounted, said lock mechanism (L; L') is capable of assuming a state permitting free relative rotation between both the holding members (H1, H2); characterized in that the lock mechanism (L; L') comprises a fastening (7; 7') rotatably supported on a base frame (1) of one of the holding members (H1, H2) and engaging means (8, 8') provided on a base frame of the other of the holding members, the fastening and the engaging means being engagable with each other only when the holding members are oriented such that the pipe sections (P1, P2), when clamped in the respective holding members (H1, H2), are at right angles to one another. A clamp fitment according to claim 1, wherein said fastening (7) is provided on each of said holding members (H1, H2). A clamp fitment according to claim 1, wherein said fastening (7, 7') is provided on only one of said holding members (H1, H2). A clamp fitment according to any one of the preceding claims, wherein said engaging means (8) is provided on each of said holding members (H1, H2). A clamp fitment according to claim 3, wherein said engaging means (8; 8') is omitted from said one of the holding members. A clamp fitment according to any one of the preceding claims, wherein said fastening (7) has a locking piece (7a) at a free end thereof and said engaging means is a recess (8) to be engaged by said locking piece (7a). A clamp fitment according to any one of claims 1 to 5, wherein said fastening (7') is a frame-type fastening and said engaging means is a locking projection (8') to be engaged by a closed free end of said frame-type fastening (7'). A clamp fitment according to any one of the preceding claims, wherein the base frames (1) of said holding members (H1, H2) each have an arcuate receiving surface (la) capable of abutting against an outer peripheral surface of the associated pipe sections (P1, P2), said base frames (1) being placed on each other and coupled by said coupler (6).

Inventors: SATO MASATARO, SATO, MASATARO
Applicants: SATO MASATARO, SATO, MASATARO
Application year: 1993
Main classification: E04G7
IPC codes: F16B7, E04G7