The present invention relates to a latch mechanism and in particular, although not exclusively, to a latch mechanism for a pipe coupling.
Latch mechanisms are widely used in many applications wherein two parts engage by sliding relative to each other and a latch secures the two parts to prevent disengagement unless the latch is first released. For instance, it is known for a pipe coupling to consist of a female coupling member that includes a socket and a male coupling member that includes a probe wherein the two coupling members are mated by inserting the probe into the socket. The mating of the male and female coupling members aligns two parts of a fluid conduit so that fluid may flow through the couplings. Once mated, a coupling pin is inserted through an aperture in the female coupling member and an aligned recess in the probe in order to lock the male and female coupling members together. The axis of the pin is arranged at right angles to the insertion axis.
To disengage the male and female coupling members, the pin is withdrawn from the recess in the probe to allow the probe to be withdrawn from the socket along the insertion axis. Accordingly, disengagement and mating of the coupling members requires two distinct movements.
It is an aim of the present invention to provide a push-pull latch mechanism that can be mated by pushing the male coupling member towards the female coupling member and can be disengaged by pulling the male coupling member away from the female coupling member both requiring only one movement.
A further application is in sub-sea moorings. Here a floating platform is secured to the sea bed by dropping anchoring ropes from the platform and connecting the ends of the ropes to an underwater platform. A known latch mechanism for connecting the ropes to the underwater platform is to form wedge-shaped radial notches in a probe of a male coupling. Ball bearings are housed in the notches and are freely movable within the wedged notches from the shallow end to the deep end. When the ball bearings are in the deep end, they do not extend substantially past the perimeter of the male coupling. To insert the probe into a socket, the ball bearings move to the deep end and the probe enters a socket of a female coupling. When inserted the ball bearings align with notches in the sockets internal wall. Accordingly, the ball bearings carry the separation load by wedging between the notches on the probe and the notches in the socket. To de-couple the latch, a cage, which encircles the probe in order to retain the ball bearings within the notches, is operable to move the ball bearings towards the deep end and therefore out of engagement with the notches in the socket.
Due to the tendency of the floating platform to move under tides, wind and/or surface water conditions, the ropes are often joined/de-coupled under load. It is not possible to join/de-couple the known latch mechanism under load. Accordingly, it is a further aim of the present to provide a latch mechanism that can be coupled and un-coupled under load.
According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.
In one aspect of the present invention, there is provided a latch mechanism for coupling a first part to a second part in a first coupling direction wherein one of the first or second parts includes a latch and the other of the first or second parts includes a catch channel, the latch and catch channel being arranged such that when the two parts are coupled the latch enters the catch channel in a second direction. The second direction is inclined to the first direction, preferably by an oblique angle. Accordingly, a latch mechanism is provided that may suitably be used in any number of applications, for instance sliding doors, flat packed furniture joints and the alike. Preferably the latch mechanism may include a number of latches. Each latch may be angled to the first direction at a same or different angle.
In another aspect of the present invention, there is provided a latch mechanism having male and female coupling members that mate in a first coupling direction by insertion of a probe into a socket. Once mated a latch on one piece enters a catch channel on the other piece in a second direction. The second direction is inclined to the first direction, preferably by an oblique angle. Accordingly, de-coupling of the male and female coupling members in a direction opposite to the first direction is prevented by engagement between the latch and catch channel. Moreover, the latch and catch channel are not in communication with the socket. This avoids any cross-contamination problems between the socket and catch channel, as might otherwise arise in fluid delivery applications of the latching mechanism. It also enables the catch channel to include different characteristics to the socket.
In the exemplary embodiments the latch is retained by the male coupling member in a sliding arrangement. The latch slides relative to the male coupling member in the second direction. The latch is biased in the second direction to extend further from the male coupling member. Here, during insertion, an end of the sliding latch abuts an end face of the socket and moves against its bias in a direction opposite to the second direction to allow the male coupling member to be inserted. Accordingly, during insertion the sliding latch moves along the female coupling members end face. When the coupling members are mated, the latch and catch channels are aligned. Thus the latch enters the catch channel due to the bias. To de-couple the coupling, the latch is pulled against the bias and in the direction opposite to the second direction. Once the latch is clear of engagement with the catch channel, further relative movement in the direction opposite to the second direction effects de-coupling of the members in the direction opposite to the first direction. Thus there is provided a push-pull latch mechanism that can be coupled and de-coupled in single movements.
Preferably, the second direction is inclined to the first direction by an acute angle. The angle may be between more than 5° or more than 15° or more than 25° or more than 40° and less than 85° or less than 75° or less than 65° or less than 50°.
In the exemplary embodiments the male coupling member and female coupling member include a probe and socket respectively. Coupling/de-coupling is achieved by insertion/withdrawal of the probe into/from the socket. The coupling members each include a first fluid conduit, the first fluid conduits being aligned when the coupling members are mated to form a fluid passageway. Preferably, the fluid passageway takes any path through the coupling. In the preferred embodiments, the fluid passageway is straight. In one exemplary embodiment, the fluid conduits are straight and the fluid passageway has an axis parallel to the second direction. In another exemplary embodiment, the fluid conduits are non-linear. Thus the fluid conduits bend. For instance, the male coupling member includes a first portion of the fluid conduit that is parallel but preferably coincident with the first direction and a second portion of the fluid conduit that is angled with respect to the first direction. The fluid conduit is continuous. The second portion of the fluid conduit includes an aperture on the circumferential face of the probe. The female coupling member also includes first and second portion of fluid conduit. The first portion is parallel to the first direction. The axis of the first portion is spaced from the axis of the first portion in the male coupling when mated. The second portion of the female member's fluid conduit is angled to the first portion. The second portion includes an aperture on the circumferential face of the socket.
Preferably, the latch comprises at least one elongate member. In the exemplary embodiments, the latch comprises a plurality of elongate members. Two or more elongate members are preferred as they increase the rotational stiffness of the coupling. Accordingly, the catch channel comprises a plurality of channels. The channels are not in communication with the socket. In the preferred embodiments the elongate members are held together by a cross-member. The cross-member includes means to enable the latch to be easily operated, for example a part giving a mechanical advantage to the operation.
Preferably the latch includes a reduced strength area. The reduced strength area may allow the latch to fracture at a given load in order to decouple the latch. The reduced strength area may be formed by one or more notches. The reduced strength area may be formed in the latch along the plane of coupling.
In a further aspect of the present invention, there is provided a method of latching male and female coupling members. The method includes inserting a male coupling member in to a female coupling member by moving a probe relative to a socket in a first direction. During insertion, continuous movement in the first direction causes a latch to enter a channel in a second direction. The channel is separate to the socket. The coupling is de-coupled by continuously moving the latch in a direction opposite to the second direction.
The method may include latching male and female coupling members as herein described.
As shown in
A latch 20 is slidably mounted on the male coupling member 12, in a second direction (B-B). A compression spring 21 biases the latch 20 so that the latch extends further from the male coupling member 12. Catch channels shown here as two holes 22 for receiving a part of the latch 20 are formed in the female coupling member. The holes 22 extend from a front face 24 of the female member 14 in the second direction (B-B).
In use, the latch mechanism 10 is coupled by continuous relative movement in the first direction between the male and female coupling members, between limit positions. Accordingly, during insertion, the latch abuts the front face 24 of the female member. Further movement causes the latch to slide relative to the probe in the second direction and against its bias, which allows the probe to further advance into the socket. In doing so, the contact point between the front face and latch also moves along the front face. When the probe is fully inserted, the latch is aligned with the holes 22. Consequently, due to the bias of the spring 21, the latch 20 enters the holes 22, in a manner to be described in detail.
Because the second direction is inclined to the first direction, when in the mated position, de-coupling of the latch mechanism is prevented by engagement between the latch 20 and the holes 22. The engagement creates a shearing force in the parts of the latch within the holes 22. Thus the load carrying characteristics of the latch mechanism is determined by the shear strength of the material used for the latch.
Accordingly, to de-couple the latch mechanism the latch 20 is moved relative to the female member 14 against its bias and in the second direction B-B. This withdraws the latch from the holes 22. Once removed from engagement, the male and female members are free to de-couple by relative movement of probe 16 and socket 18 in the first direction A-A. The movement is continuous, between the end positions. The force effecting the movement can be applied all in the first direction or all in the second direction. It will be appreciated that the force effecting the movement could also be a summation of forces in both directions.
Referring to
The male coupling member 12 comprises a tubular section 32. One end of the tubular section comprises the probe 16. A straight fluid conduit 34 is formed between an end face of the probe 16 and a conduit fitting (not shown). A sealing ring 36 is arranged in an annular groove 38 formed toward the probe's distal end. The male coupling member 12 includes a collar 40. The collar 40 is arranged fast to the male member 12. Two through holes 41 are formed in the collar 40 along the second direction.
The latch 20 comprises two prongs 42 connected by a plate 44. The plate is arranged, in use, perpendicularly to the first direction. Accordingly, the prongs 42 are secured fast to the plate 44 at an angle. The prongs locate in the through holes 41. Accordingly, the latch is restrained by the male member's collar 40 to slide in the second direction.
The plate 44 is substantially U-shaped. This allows the plate 44 to be assembled to the male member by sliding the prongs 42 into the holes 41. Once assembled, the spring can be arranged about the tubular male member 16 with one end abutting a rear face of the plate 44. A circlip 46 can then be arranged on the male member to give the spring 21 a fixed point to operate against. The spring 41 thereby biases the plate 44 against the collar 40. In this position, the pins extend from the collar 40.
Referring to
Referring to
Referring to
Referring to
The sprung cir-clip 82 is shown in more detail in
As shown in
In a further embodiment, and referring to
The latch mechanism operates substantially as herein described. However, a slot 94 is formed in the male coupling 12 and the latch is accessible through the slot. Furthermore, one side 96 of the slot acts and as a stop for a compression spring 98 to act against.
Consequently, the notches 99 provide a predetermined fracture point through the prongs. Accordingly, a known break-out strength can be imparted on the latch mechanism, at which point the pins will shear and the parts be able to de-couple. It will be appreciated that such notches could be incorporated into any of the embodiments herein described.
Referring to
Referring to
The latch mechanism herein described provides a push-pull coupling that is able to be coupled and de-coupled under load and that has positive engagement.
Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
Number | Date | Country | Kind |
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0808252.1 | May 2008 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2009/050472 | 5/7/2009 | WO | 00 | 2/3/2011 |