Hook connector with snap closure

Abstract: A connector with snap closure comprises a pair of levers (3, 3') elastically stressed, each lever (3, 3') having a formed end (8, 8') for performing the closure for the connector (1), and the other formed end (9, 9'; 10, 10') for providing a snap element and an element for manual control of opening of the connector (1).

Description: The present invention relates to a hook connector with snap closure which is used for hooking an external rigid element such as an eyelet of a piton, a bar or the like. A hook connector of this type has a lever for closure of the hook connector which remains open untill the external rigid element exerts an appropriate pressure on an appropriate snap part of the connector there-by determining the closure of the connector. The snap closure of the connector avoids inconvenient of having to open the connector for hooking the external rigid element to be hooked, and also of having to operate with the same hand in order to open the connector and keep it open. A hook connector with snap closure of this type is disclosed in EP-A-0465995 and is formed by a generally C shaped rigid body having a mouth portion and a containing area for inserting an external rigid element and a sliding part elastically biased to perform closure of the connector. In particular the sliding part is jointed to a manual control part and is actuated in closure by means of an appropriate snap part. The snap part in turn is provided with snap means for hooking with the manual control part and the sliding part. The presence of a plurality of parts and connections between the snap part and the remaining parts of the connector may cause jamming thereof due to dust or external agents, and simultaneously restricts the performances thereof in terms of accuracy of the value of the force which permits release of the snap part and consequently closure of the same connector. A connector of this type thus can have a complex structure and become expensive. The object of the present invention is that of providing a hook connector with snap closure which eliminates the disadvantages found with traditional devices and which offers high standards of performances and is found to be reliable, simple, rugged and inexpensive. Another object of the present invention is that of providing a hook connector which does not allow accidental opening in the case of impact or rubbing against the rock or the rope. These and other objects are achieved using the hook connector with snap closure of the present invention, in accordance with the independent claim listed hereinbelow. The hook connector of the present invention is characterised by the presence of a lever or of a pair of levers elastically biased and whereon the means of closure of the connector are formed in one single piece, consisting of the element of closure of the mouth portion of the generally C shaped rigid body, the part for manual control of the opening of the connector and the snap element of the connector. The advantage of providing a lever with a profile adapted and designed to perform three different functions, that is to say closure, manual resetting and snap of the connector, lies in the fact that the total number of the parts and of the relevant interconnections is considerably reduced, thus appreciably simplifying the device and in particular the mechanism of release of the snap and simultaneously ensuring reliable operation and accurate performances. A preferred embodiment of the present invention will be described with reference to the accompanying drawings, in which: Figs. 1a and 1b show a plan view of a connector and respectively of a detail of a connector with two levers according to the present invention in an opening position; Figs. 2a and 2b show a plan view of the connector of the previous figure in a closure position. Fig. 3 is a perspective view of a lever of the connector of the previous figures. Fig. 4 shows a plan view of a detail of a connector with only one lever according to the present invention. In the various accompanying drawings the corresponding parts of the connector are denoted by identical reference signs. In Figs. 1a, 1b, 2a, 2b and 3 the connector 1 is shown according to a preferred embodiment. The connector 1 comprises a rigid body formed by two symmetrical parts defining a general C shape and denoted by 2, whereon two levers 3 and 3', with identical shape, are supported for rotation around the common pin 4 and are arranged symmetrically in relation to the axis of the rigid body 2 passing through the pin 4. The rigid body 2 is provided with a front mouth portion 5 for access to an area 6 for containing the element to be hooked to the connector, formed for example by the eyelet of a piton, and, on the opposite side, by an appropriately shaped hole 17, designed to house a tape or a rope. In a variant of the present embodiment a wall of the hole 17 of the rigid body 2 can be removed to allow opening of the hole 17 and consequently easy replacement of the tape or rope contained therein. The levers 3 and 3' have been appropriately shaped in order to perform unhooking without the need for additional parts. Each lever 3 and 3' is thus formed by a longitudinal plate 7, 7', having a first projecting end 8,8' turned towards the mouth portion 5 an, being transversally bent towards the inside of the connector 1. The other end of the plate 7, 7' extends with a first and a second transverse fin 9, 9' and 10, 10', of which the first 9, 9' is arranged in relation to the plate 7, 7' on the same part as the projecting end 8, 8', while the second 10, 10' is arranged on the opposite side. The external edge of the projecting end 8, 8' has a profile describing a circumference arc with centre in 4. A support pin 12, 12' in stainless steel, or another suitable material, attached to the end 21, 21' of the plate 11, 11' of the rigid body 2, is positioned at such a distance from the centre 4 so as to rest on the external edge of the projecting end 8,8' without hindering rotation of the same 8, 8'. The part of the profile of the projecting end 8, 8' which is shaped as a circumference arc can therefore slide adjacent to the support pin 12, 12' and perform an angular stroke which stops during opening when the fin 10, 10' strikes a stop pin 13, 13' attached to the end 22, 22' of the plates 11 and 11' of the rigid body 2, and during closure when the pin 12, 12' engages a flap 14, 14' of the external edge of the projecting end 8, 8'. A return spring formed by a curved metal wire 15 is hinged on two symmetrical points 16 and 16' of the levers 3 and 3' in such a way that the line joining the two points 16 and 16' (denoted by a dotted and dashed line in Figs. 1b and 2b) lies below the rotation pin 4 in opened position of the connector 1, and above the rotation pin 4 in closed position of the connector 1. In the case wherein a different tension is to be given to the return spring, the hinging points 16 and 16' can be provided on the levers 3 and 3' also in an asymmetrical position. The housing of the metal wire 15 is formed by the reduction in thickness of the levers 3 and 3' between which the metal wire 15 can therefore be placed. The metal wire 15 must have a shape compatible with the movements necessary inside the device, that is to say that it must not tangle with the rotation pin 4. The following is an illustration of the functioning of the connector 1. The connector 1 is first brought into the position of opening. In order to do this, the fins 10 and 10' have to be pulled with the fingers, which fins act as an element for manually operating the levers 3 and 3' from the closed to the opened position of the connector 1, in that they cause the simultaneous rotation of the levers 3 and 3' until they strike the stop pins 13 and 13'. The levers 3 and 3' maintain this position given that the line joining the points 16 and 16' and lying below the centre 4 coincides with the line of action of the metal wire 15 on the same levers 3 and 3'. The force indicated by Fa then generates on the levers 3 and 3' a torque which keeps them open and in contact with the stop pins 13 and 13'. The correct positioning of the stop pin 13, 13' is essential for ensuring that, when the connector is open, the projecting end 8, 8' completely frees the front mouthpiece 5 of the rigid body 2 and the fin 9, 9' is arranged in a central portion of the containing area. The fins 9 and 9' function as a snap element. When the body to be hooked to the connector 1, for example the eyelet of a piton, penetrates the containing area 6 through the front mouth portion 5 and presses between the tips of the fins 9 and 9', the levers 3 and 3' tend to rotate for closure of the connector 1, but are opposed by the action of the metal wire 15. However at the moment when, due to the pressure exerted by the element to be hooked, the rotation of the levers 3 and 3' is sufficient to make the line joining the points 16 and 16' move from below to above the centre 4 which acts as a fulcrum, the levers 3 and 3' are released for closure of the connector 1. More particularly the projecting end 8 and 8', following rotation of the levers 3 and 3', act as elements for closure of the connector 1, completely invading the front mounth portion 5 and confining the body to be hooked inside the confining area 6. The structural simplification introduced by providing a lever 3, 3' is therefore clear, which lever, by means of an appropriate design of its profile, incorporates in one single piece the means of closure, that is to say the element of closure of the mouth portion of the generally C shaped rigid body 2, the element of manual control of opening and the snap element of the connector, and performs all the functions with extreme simplicity. The rotation for closure of the levers 3 and 3' stops when the flaps 14 and 14' engage in the pins 12 and 12'. Together with this use of them, the support pins 12 and 12', with the pin 4, naturally also serve to absorb the traction stresses transmitted by the levers 3 and 3'. Fig. 2a shows also that the dynamics of closure of the connector leads to a configuration wherein the movement of the body to be hooked in the containing area 6 is not hindered by the fins 9 and 9' used for the snap, the latter moving to take up position between the plates 11 and 11' of the two parts forming the rigid body 2 in such a way as to free the containing area 6 completely. So that the connector 1 can only be "actuated" when the levers are both brought into a position of complete opening and that it moves into a closure position when the levers are released from any other position which is not that of opening, the arrangement of the points 16 and 16' in relation to the rotation pin 4 is chosen carefully, bearing in mind that the connector 1 only remains open if the direction of the force of the spring 15 on the levers 3 and 3' goes beyond the centre of rotation 4 of the same and localising this type of behaviour only at the limit of the stroke of opening of the levers 3 and 3'. The presence of two levers in this embodiment guarantees against opening in the case of rubbing or impact against the face or rock. In order to open the connector, both projecting end 8 and 8' must clear completely the front mouth portion 5 of the generally C shaped rigid body 2. Impact or rubbing against faces and rocks may cause the opening of one single lever, but the opening of the connector is very unlikely, which requires instead a combined and simultaneous action on both levers. The symmetry of the two parts which make up the generally C shaped rigid body 2 and of the two levers 3,3' also allows these elements to be obtained from a single mould, thus simplifying the manufacturing process and consequently reducing the costs. Fig. 4 shows another embodiment of the present invention wherein the connector 1 is formed by a single lever 3. In this case the return spring 15 is hinged at one end on the lever 3 and at the other end on one plate 11 of the generally C shaped rigid body 2. A connector with two levers can be devised according to the invention and which has each lever hinged on a respective rotation pin. According to another possible variant finally the elastic part can be in the form of an appropriately shaped plate whose ends engage on two notches appropriately formed on each lever in the case of a connector with two levers, and on the lever and on the plate of the rigid body in the case of a connector with a single lever.

Claims: A hook connector (1) with snap closure comprising: a generally C shaped rigid body (2) having a mouth portion (5) and a containing area (6) for inserting an external element, to which the connector has to be hooked and a hole (17) for attachment of a tape or a rope, a lever or a pair of levers (3, 3') elastically biased with a spring (15) and rotatably supported on said rigid C shaped body (2), said levers being rotatable between an opened and a closed position of the connector (1); characterised in that each lever (3, 3') has a first projecting end (8, 8') turned toward said mouth portion (5) and being transversally bent towards the inside of the connector (1) and projectable into said containing area (6) in the closed position for the connector (1) and an opposite end with first transverse fins (9, 9') extending towards the inside of the connector (1) and projectable into said containing area (6) in the opened position of the connector (1) in order to act as a snap element, and with second fins (10, 10') extending outwardly from the levers (3, 3') of the connector (1) and used as an element for manual operating the levers from the closed to the opened position of the connector (1). A hook connector (1) with snap closure according to the previous claim, characterised in that a single rotation pin (4) is (4) provided on said generally C shaped rigid body (2) for rotatably supporting said pair of levers (3, 3'). A hook connector (1) with snap closure according to claim 1, characterised in that a respective rotation pin for each lever (3, 3') is provided on said generally C shaped the rigid body (2) for rotatably supporting each lever (3, 3'). A hook connector (1) with snap closure according to any previous claims, characterised in that said first projecting end (8, 8') of each lever (3, 3') has an arc shaped external edge and in that for each lever (3, 3') a respective pin (12, 12') fixed to said generally C shaped rigid body (2) is provided in order to slidably support said arc shaped external edge of the first projecting end (8, 8') of each lever (3, 3'). A hook connector (1) with snap closure according to the previous claim, characterised in that on said first projecting end (8, 8') a blocking part for said first projecting end (8, 8') is provided which can be engaged with said respective pin (12, 12') for slidably supporting said first projecting end (8, 8') of each lever (3, 3') at the closed position for the connector (1), said closed position for the connector (1) being achieved when said first projecting end (8,8') invades completely the mouth portion (5) of the generally C shaped rigid body (2). A hook connector (1) with snap closure according to the previous claim, characterised in that said blocking part is in the form of a flap (14, 14') of the external edge of said first projecting end (8, 8'). A hook connector (1) with snap closure according to any of previous claims, characterised in that to each lever (3, 3') a respective stop pin (13, 13') provided on said generally C shaped rigid body (2) can be connected to stop the stroke of each lever (3, 3') in the opened position of the connector (1), said opened position being achieved when said first projecting end (8, 8') completely frees the mouth portion (5) of the generally C shaped rigid body (2) and said first transverse fin (9, 9') is arranged frontally to said mouth portion (5) and substantially in the centre of said containing area (6). A hook connector (1) with snap closure according to any one of the previous claims and having one single lever (3), characterised in that a return spring (15) which has a first point of hinging provided on said single lever (3) and a second point of hinging provided on said generally C shaped rigid body (2) is provided for elastic biasing of said single lever (3), said return spring (15) performing respectively the closure or the opening of the connector (1) whether the line joining said first and second points of hinging is brought above said rotation pin (4) or below said rotation pin (4). A hook connector (1) with snap closure according to any one of claims 2 to 7 and having a pair of levers (3, 3'), characterised in that a return spring (15) which has a first point (16) of hinging provided on one lever (3) of said pair of levers (3, 3') and a second point (16') of hinging provided on the other lever (3') of said pair of levers (3, 3') is provided for elastic biasing of said pair of levers (3, 3'), said return spring performing respectively the closure or the opening of the connector (1) whether the line joining said first (16) and second (16') points of hinging is brought above said rotation pin (4) or below said rotation pin (4). A hook connector (1) with snap closure according to the previous claim, characterised in that said pair of levers (3, 3') is formed by two identical levers (3, 3') and in that said first (16) and second (16') points of hinging are provided on said pair of levers (3, 3') in a symmetrical position. A hook connector (1) with snap closure according to claims 8 to 10, characterised in that a housing is provided for said return spring (15), said housing being formed by a reduction in the thickness of said one lever or pair of levers (3, 3'). A hook connector (1) with snap closure according to any of previous claims, characterised in that an openable wall is provided on said hole (17) for housing a tape or a rope to allow replacement of said tape or said rope.

Inventors: BONAITI MARCO, BONAITI, MARCO
Applicants: KONG SPA, KONG S.P.A.
Application year: 1999
Main classification: F16B45
IPC codes: F16B45