GB2185066A - Clamp in the form of a one piece flexible closure - Google Patents

Abstract

The clamp is moulded in one piece from an elastomeric plastics material and has a semi-cylindrical portion 52 forming a flexible spring, a fixed jaw 54 consisting of one of the end portions of the portion 52, and a substantially semi-cylindrical movable jaw 42 articulated, at an intermediate point along its length, to the other end of the portion 52 by a first thin pliable external hinge 44, and at one of its ends to a toggle portion 46 by a hinge 48, the toggle portion 46 itself being articulated by a second thin pliable external hinge 50 to the portion 52 at a point offset relative to the free end of the fixed jaw 54, the sum of the distances between the internal hinge 48 which articulates the movable jaw 42 on the knuckle-joint portion 46 and the external hinges 44 and 50 being greater than the distance between the external hinges 44 and 50 when the portion 52 forming the spring is in a released condition, and being slightly shorter than the developed length of said portion 52 forming the spring. A resilient tongue 64 connected to the toggle portion 46 serves to hold a member being clamped and is capable of holding members of very small diameter but does not obstruct the mouth of the clamp when the latter is open. <IMAGE>

Description

SPECIFICATION Clamp in the form of a one piece flexible closure This invention relates to a moulded clamp intended to secure elongate objects, such as tools, and made in one piece by moulding from an elastomer plastics materiai, for exam ple polypropylene.

From patentapplicationPCT78/O0003thereis already known a clamp of this type. For a better un- derstanding of the defects of this clamp and of the means used according to the invention to remedy them,theknownclampwill nowbedescribed in detail with reference to figures 1 and 2 of the ac co m pa nyi n g d rawi n g s, wh ich show the cla m p i n the open position and in the closed position.

The clamp comprises a base 10 by means of which it can be fixed to a support, a portion 12 forming a spring and intheform of a half-ring, integral at its middle with the base 10 and thus describing on either side of the lattertwo arms,18,20, and two jaws 14, 16, likewise in the form of half-rings. The jaws 14, 16 are interconnected in an articulated manneratoneoftheirfurthermorearticulatetothe ends of the arms 18, 20 by small and pliable external hinges,24,26.

The sum of the distances between internal hinge 22 and external hinges 24,26 is greaterthan distance a between the latter and is slightly less than the developed length ofthe portion forming spring 12. The result of this is that when the clamp is open the internal hinge 22 is located about the straight line iinking the external hinges 24,26. If the jaws 14,16, are brought together, hinge 22 on figure 1 descends, thus flexibly pushing arms 18,20 outwards and, once it has passed dead centre consisting of the abovementioned line, jaws, 14, 16 are snapped shut bythe spring action of 16 when closed describe between them a substantially circular passage, the diameter of which corresponds to the maximum diameter of the object which can be secured with the clamp.One ofthejaws, is isextended by an appendage 28 straddling the other jaw 14 and providing a finger holdfortheusertoopentheclamp.

The clamp furthermore comprises a flexible retaining tongue 30 which is moulded together with jaw 16, in the vicinity of internal hinge 22. This tongue 30 serves to secure between the jaws objects having a diameter small than that of the ring formed bythe closed jaws 14,16.

While such a clamp is efficient inthe majorityof applications, it has two major defects: firstly, as will be seen on comparing figure 1 and 2, the total width b of the open clamp is much greater than its width c in the closed position. It is cleartherefore that to en ablethejaws 14, 16to be opened totheirmaximum spacing the clamp must be located in an area free from any obstacle over a length at least equal to b. In particular, several of these clamps cannot be placed side by side. This condition naturally constitutes a serious constraint to the use of the clamp.

Moreover, as can be seen on figure 2, retaining tongue 30 in its rest position extends substantially across the diameter of the ring formed by the jaws, so that it cannot effectively secure objects having diameterssmallerthanthe minimum diametercorresponding to the distance between the tongue 30 and jaw 14.

It is true that this disadvantage could be remedied by placing the tongue closerto jaw 14, as shown in dotted outline offigure 1, but in this event with the clamp open (figure 1)thetongue30would be located in the middle of the opening ofthe clamp and would thus preventthe insertion of the objects to be secured between the jaws 14,16. Furthermore, in the caseofsmalldiameterobjectsitwill be necessary to ensure that they do not slip between the tongue 30 and the jaw 16.

According to the present invention there is provided a clamp moulded in one piece from an elastomer plastics material comprising a semi-circular portion forming a flexible spring, a fixed jaw formed by one of the end portions ofthe semi-circular portion, a substantially semi-circuiar movable jaw articulated at an intermediate point along its length to the other end of the semi-circular portion by a first thin pliable hinge, and at one of its ends to a knucklejoint portion articulated by a second thin pliable hinge to said semi-circular portion at a point displaced from the free end of the fixed jaw, the sum of the distances between the hinge which articulates the movable jaw to the knuckle-joint portion and the first and second hinges when being greaterthan the distance between the first and second hinges when the semi-circular portion forming the spring is in are- leased condition, and being slightly shorterthan the developed length of the said semi-circular portion forming the spring.

The clamp according to the invention preferably includes a flexibly deformable retaining tongue connected to the knuckle-joint portioln i n the vicinity of the second hinge, said tongue having in its unstressed state a curved form such that in the closed position ofthe clamp it lies adjacent to the knucklejoint portion and the movable jaw with little deviation therefrom, and that in the open position ofthe clamp its free end is in contact with or close to the free end of the fixed jaw.

It is clear, then, that when the clamp is open the gap comprised between the ends of the jaws is substantially clear and that objects can therefore be inserted between the jaws without any difficulty.

Additionally, the tongue when provided can exert a gripping effect on objects of relatively small diameters.

According to a further feature of the invention, locking of the clamp in the closed position is enhanced by the provision of a lug on the movable jaw and a notch which is formed on the semi-circular portion forming the spring and are capable of engaging with one another.

An embodiment of the invention will now be described, byway of example, with reference to the accompanying drawings, in which: Figures land 2 are elevational views of the known clamp described hereinbefore, In the open position and in the closed position; Figures3and 4are similarviewsof a clamp ac- cording to the present invention; Figure 5 shows an object of small diametersec ured in the clamp according to the present invention, and Figures 6to Sshowthree consecutive views of the placing of a large diameter object in the clamp according to the present invention.

With reference to figures 3 and 4, the clamp according to the invention is made in one piece by moulding from an elastomerplastics material and comprises a member40 in the form of a half-ring and a substantially semi-circular movable jaw 42 which is articulated at an intermediate point along its length to one of the ends of the member 40. The articulation consists of a thin pliable hinge 44.

According to a feature of the invention, the movable jaw 42 is additionally articulated at its internal end to one end of a bow-shaped knuckle-joint portion 46, the other end of which is itself articulated to the semi-circular member 40 at an intermediate point along the length of the members, the two above-mentioned articulations likewise consisting of thin pliable hinges 48,50.

Hinge 50 thus defines, on semicircular member40, two portions: a portion 52 forming flexible spring which extends between hinges 44 and 50 and a free end portion 54. The latter performs the role of a fixed jaw. It has on the external face of its free end indentations 56 which can be engaged by a hook 58 prov ided atthe free end of movable jaw42.

Thus, in relation to the clamp shown in figures 1 and 2, it will be seen that hinge 26 has been replaced by hinge 50, thus making it possible to reduce the movable jaw 16to a simple knuckle-joint and to replace the said movable jaw 16 by fixed jaw 54. The result of this arrangement isthatonlythe movable jaw is opened and closed and that its deflection takes place principally within the volume limits ofthe semi-circular portion 40, without projecting laterally therefrom. Ittherefore becomes possible to place clamps side by side. Forthis purpose the clamp is provided in the vicinity ofthe ends of the portion 40 with a male attachment 60 and with a female attachment 62 allowing the connection of clamps placed against one another.

According to another significantfeature of the invention, the clamp comprises a flexible retaining tongue 64which is connected to the knuckle joint portion 46 in the vicinity of hinge 50 by a slightly curved semi-circular portion 66. The tongue 64 is bow-shaped so that, in the closed position of the clamp (figure 4) it lies adjacent to the knuckle-joint portion 46 and part of movable jaw 42 with very little deviation therefrom. It is clearthatthe tongue 64 can thus retain small diameter objects 68 (figure 5).

Furthermore, as shown in figure 3, in the open position ofthe clamp the tongue 64 is virtually withdrawn from the jaw 42 and its free end is very close to or in contact with the end of fixed jaw 54. The opening between the jaws 42 and 54 is substantially clear and therefore allows trouble-free insertion of the objects to be clamped Locking of the jaws in the closed position is enhanced by the provision on movable jaw 42 of a lug 70 which locates in a notch 72 formed in portion 40.

Figures 6to 8 show the successive deformations of the clamp according to the invention when it is used to secure an object 74 having a diameterslightly smallerthanthe maximum diameterwhich it can accommodate. With the object 74 inserted between the jaws 42, 54, the movable jaw 42 is moved towards the fixed jaw 54. At the start of this movement, the object74 is pushed bythe tongue 64 and becomes wedged in the recess of the movable jaw 42. The gap between the movable jaw 42 and the tongue 64continu#esto close and it is nowthe tonguewhich is pushed by the object 74. Semi-circular portion 66 by which the tongue 64 is attached to the knuckle-joint portion 46 opens gradually and the tongue 64 moves towards the fixed jaw 54.During this time, the portion 52 forming flexible spring opens and thus stores potential energy. Once the internal hinge 48 has passed the straight line linking external hinges44,50 (figure 7) the portion 52 forming the spring is snapped shut, thus pressing the movable jaw42 against the fixed jaw 54. During this movement, object 74 again pushes tongue 64 until the end of the latter is applied against the fixed jaw 54, after which the tongue 64 is flexibly deformed throughout its length. At the end of stroke ofthe movable jaw 42 its hook 58 becomes engaged with an indentation 56 and the lug 70 engages in the notch 72.

The invention therefore provides a clamp capable of being used for many applications in the home, in the workshop, in the garden of wheresoever objects need to be fixed in a detachable manner. It can advantageously replace suspension hooks.

Claims (4)

1. A clamp moulded in one piece from an elastomer plastics material comprising a semi-circular portion forming a flexible spring, a fixed jaw formed by one ofthe end portions of the semi-circular portion, a substantially semi-circuiar movable jaw articulated atan intermediate point along its length to the other end of the semi-circular portion by a first thin pliable hinge, and at one of its ends to a knucklejoint portion articulated by a second thin pliable hinge to said semi-circular portion at a pointdisplaced from the free end of the fixed jaw, the sum of the distances between the hinge which articulates the movable jaw to the knucklejoint portion and the first and second hinges when being greater than the distance between the first and second hinges when the semi-circular portion forming the spring is in are- leased condition, and being slightly shorter than the developed length of the said semi-circular portion forming the spring.

2. A clamp as claimed in claim 1, in which it includes a flexibly deformable retaining tongue connected to the knuckle-joint portion in the vicinity ofthe second hinge, said tongue having in its unstressed state a curved form such that in the closed position of the clamp it lies adjacent to the knuckle-joint portion and the movable jaw with little deviation therefrom, and that in the open position ofthe clamp its free end is in contact with or close to the free end of the fixed jaw.

3. A clamp as claimed in claim 1 or claim 2, in which locking ofthe clamp in the closed position is enhanced by the provision of a lug on the movable jaw and a notch which is formed on the semi-circular portion forming the spring and are capable of engaging with one another.

4. A clamp substantially as hereinbefore described with reference to and as illustrated in Figures 3 to 8 of the accompanying drawings.