Patent Application
20160237726
1. Field of the Invention
The present invention relates to a case latch assembly.
2. Brief Discussion of the Related Art
Case latches for securing the lid and body of a case together are well known and typically comprise first and second parts of a split dish, each part being externally mounted respectively on the body and lid of a case. The first part is typically provided with a rotatably mounted hinge plate comprising a slider element moveably mounted on the hinge plate. The slider element comprises a latch hook and is arranged to move by means of an actuator. A catch plate is provided on the second part of the split dish, and the latch hook is adapted to hook onto the catch plate, and hold the case closed. To open the latch, the actuator is operated by a user to move the latch hook out of engagement with the catch plate, and the hinge plate may then be rotated by the user so that the latch hook is swung up and away from the catch plate to allow the case to be opened.
According to an aspect of the present invention, there is provided a case latch assembly, comprising:
a strike plate member provided on a first lock mounting part;
a hinge member mounted on a second lock mounting part for pivotal movement about a pivot;
a reciprocating element mounted for reciprocal movement on the hinge member, the reciprocating element comprising a strike plate engagement portion to a side of the pivot nearest to the first lock mounting part for engaging with the strike plate member, and a cantilever portion which extends to the side of the pivot furthest from the first lock mounting part; and
a torsion element being arranged to apply torsion to the hinge member to bias the strike plate engagement portion away from the strike plate member;
wherein, as the reciprocating element moves between a first position and a second position, the cantilever portion interacts with a constraining formation on the second lock mounting part to offset the bias applied by the torsion element to cause the strike plate engagement portion to be deflected towards the strike plate member.
The interaction between the cantilever portion of the reciprocating element and the constraining formation effectively controls the movement profile or path followed by the strike plate engagement portion as the reciprocating member is retracted and extended on the hinge member. The movement path for the engagement portion to engage with and disengage from the strike plate member can therefore be defined by the shape and configuration of the cantilever portion of the reciprocating element and the constraining formation. The first position is preferably further from the pivot than the second position, such that the engagement portion moves into engagement with the strike plate member when the reciprocating element is retracted and disengages from the strike plate member when the reciprocating element is extended. Furthermore, due to the bias provided by the torsion element, when the strike plate engagement portion is generally in the open position a user may override the bias such that the strike plate engagement portion engages the strike plate member even when the cantilever and/or constraining formation fail, or when the first lock mounting part is spaced apart from the second lock mounting part.
The constraining formation may be provided to the side of the pivot furthest from the first lock mounting part.
When the reciprocating element moves in a first direction between the first position and the second position, the constraining formation may cause the cantilever portion to pivot in a first rotational direction up and away from the second lock mounting part, and consequently the strike plate engagement portion to pivot in the first rotational direction down and towards the strike plate member. Then, when the reciprocating element moves in a second direction opposite to the first direction between the first position and the second position, the constraining formation may cause the cantilever portion to pivot in a second rotational direction opposite to the first rotational direction down and towards the second lock mounting part and consequently the strike plate engagement portion to pivot in the second rotational direction up and away from the strike plate member.
The torsion applied by the torsion element urges the cantilever portion against the constraining formation, and as the reciprocating element moves between the first position and the second position, the cantilever portion slides along the constraining formation.
While the constraining formation may be a flat inside surface of the second lock mounting part, preferably the constraining formation comprises a ramp. As the cantilever portion climbs up the ramp, the hinge member is caused to pivot against the bias to rotate the strike plate engagement portion towards the strike plate member. Similarly, as the cantilever portion drops down the ramp, the hinge member is caused to pivot under the bias to rotate the strike plate engagement portion away from the strike plate member. Preferably, the ramp forms an inside surface of a ramp insert.
In one embodiment, the constraining formation comprises a rivet. The rivet may be provided instead of a ramp. Alternatively, a ramp may be provided as described above, and may be secured in place with a rivet. In the latter case, the rivet may be positioned and shaped to define a constraining formation against which the cantilever portion can interact in the event that the ramp should fail. In other words, a rivet used to secure the ramp in place may also act as a back-up ramp should the ramp itself fail.
One of the cantilever portion and the constraining formation may comprise a protrusion and the other comprise a depression, the protrusion engaging with the depression when the case latch assembly is in a closed position. The engagement between the protrusion and the depression advantageously inhibits the reciprocating member from sliding away from the closed position, and also provides the user with positive feedback (noise and/or vibration) indicating that the latch has reached the fully closed position.
The constraining formation may comprise a first planar surface at a first elevation, against which the cantilever portion rests when the reciprocating element is at the first position. The constraining formation may comprise a second planar surface at a second elevation, against which the cantilever portion rests when the reciprocating element is at the second position. The constraining formation may comprise a curved or planar sloped surface which joins the first and second planar surfaces, and over which the cantilever portion is required to travel when the reciprocating element moves between the first and second positions.
The strike plate engagement portion and the cantilever portion of the reciprocating element are preferably formed from a single piece of material.
In an embodiment, the first and second lock mounting parts comprise respective first and second mounting dishes, the first and second mounting dishes together comprising a latch dish. This may enable the first and second mounting dishes to be received by respective recesses in a case so that the case latch assembly is mounted substantially flush with a surface of the case.
Embodiments of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:
Referring to
The first 12 and second 14 lock mounting parts comprise respective first and second mounting dishes. The mounting dishes 12, 14 together form a latch dish and are arranged to be respectively located on the lid and body of a case. Each mounting dish 12, 14 is arranged to be located in a respective aperture (not shown) in the case (not shown) so that the mounting dishes 12, 14 may be mounted substantially flush with a surface of the case.
The strike plate member 18 is mounted on the first mounting dish 12 and defines a strike plate aperture 28. The strike plate member 18 further comprises a strike plate ramp 27 provided at an edge of the strike plate member 18 substantially facing the strike plate engagement portion 20a of the reciprocating element 20.
The case latch 10 further comprises a mounting element 30. The mounting element 30 is provided on the second mounting dish 14 and is configured to receive a pair of mounting springs 32a, 32b. The hinge member 16 is mounted for pivotable movement on the springs 32a, 32b. The springs 32a, 32b are configured to apply tension to the hinge member 16 to thereby bias the strike plate engagement portion 20a of the reciprocating element 20 away from the strike plate member 18 when the case latch 10 is in an open position. This bias can be overcome either by the cantilever assisted process described below, or by the user manually pressing down on the reciprocating element 20. The hinge member 16 is provided with a mounting hook 34 at one end and a circular retaining aperture 36. The cam pin 24 and the coupling pin 26 are located through the retaining aperture which constrains their movement. The mounting hook 34 is located around the mounting springs 32 such that the hinge member 16 is mounted for pivotable movement.
The first 32a and second 32b mounting springs may, in other embodiments, be replaced with any other torsion elements capable of biasing the strike plate engagement portion 20a of the reciprocating element 20 away from the strike plate member 18. In the present embodiment, the first spring 32a comprises a first fixing part 76 and a first hinge mounting part 78. The first spring further comprises a key element 80 provided on the first hinge mounting part. In this example, the key element 80 comprises a tab extending generally outwardly from the first hinge mounting part 78. The second spring 32b comprises a second fixing part 82 and a second hinge mounting part 84.
In this example, the mounting element 30 comprises first (not shown) and second 86 mounting apertures, and first (not shown) and second 88 fixing apertures. The first and second fixing apertures are arranged to receive and couple the respective first 76 and second 82 fixing parts such that the first 32a and second 32b torsion springs form a spaced pair oppositely located about the mounting element 30. The first 78 and second 84 hinge mounting parts are provided through the respective first and second 86 mounting apertures substantially towards each other such that together they form a hinge mount (not shown). The mounting hook 34 defines an engagement slot (not shown) and the hinge member 16 is mounted on the hinge mount with the mounting hook closely receiving and substantially coupling with the hinge mount such that the tab 80 is engaged with the engagement slot. The mounting hook 34 enables the hinge member 16 to be both coupled to the torsion springs 32a, 32b and to provide engagement of the hinge member 16 with the tab 80 through a single element.
The first 32a and second 32b torsion springs are each arranged to provide a torsion biasing force to bias the hinge body 16 substantially away from the second mounting dish 14. The tab 80 is arranged to provide additional transfer of torsional force from the first torsion spring 32a to the hinge body 16 and is arranged to bias the hinge body away from the second mounting dish 14. It will be appreciated that in a different embodiment the angle of the tab 80 with respect to the mounting hook 34 may be altered to transfer a different amount of torsional force to the hinge body 16. In this example, the second torsion spring 32b does not comprise a tab but it will be appreciated that in a different embodiment it may comprise a tab.
The reciprocating element 20 is mounted for reciprocal linear movement on the hinge member 16. The reciprocating element 20 has a coupling slot 38 and a cam slot 40 provided in it. The coupling slot 38 extends generally lengthways and the cam slot 40 extends generally crossways. The coupling slot has a curved shape, to more closely match the curved path of the coupling pin 26 during actuation of the case latch. The curved shape may constrain the path of the coupling pin without interfering with the motion of the reciprocating element 20, which may ensure smooth movement of the strike plate engagement portion 20a between the closed and extended positions. The cam slot 40 extends generally from the central region of the coupling slot 38. The coupling slot 38 and the cam slot 40 are provided together as a single generally mushroom-shaped slot. The strike plate engagement portion 20a of the reciprocating element 20 is provided with a strike plate hook 44. The hook 44 is configured to engage the strike plate member 18, through its aperture 28, when the case latch is in a closed, locked position.
Referring again to the torsion springs 32a, 32b, in addition to applying the torsional bias, the coupling of the hinge member 16 to the mounting element 30 via the torsion springs 32a, 32b results in tension between the first 12 and second 14 lock mounting parts. This is because, once the hook 44 is fully engaged with the strike plate member 18, further movement of the reciprocating element 20 on the hinge member 16 deforms the springs 32a, 32b (which are the only deformable element between the hook 44 and the mounting element 30), and this deformation acts to “pull” the first 12 lock mounting part towards the second lock mounting part 14, holding them together. It also allows for a certain amount of shock absorption should the case be bumped, forcing the lid away from the body of the case.
The lock nut 22 is rotatably mounted and is provided with an actuation key 42 for manual rotation of the lock nut 22 by a user. The cam pin 24 is connected to the lock nut 22 at an off-centre position and is located through and engaged with the cam slot 40. The coupling pin 26 is connected to the lock nut 22 at a second position and is located through the coupling slot 38. Both pins 24, 26 extend through the aperture 36 in the hinge member 36.
In use, the case latch assembly 10 is operated by a user manually rotating the lock nut 22 with the actuation key 42. The rotation of the lock nut is translated by movement of the cam pin 24 within the cam slot 40 into linear movement of the reciprocating element 20 between a first position (in which the reciprocating element is extended away from the pivot) and a second position (in which the reciprocating element is retracted towards the pivot). During rotation of the lock nut 22 and the strike plate engagement member 20 the coupling pin 26 moves along the coupling slot 38.
In the extended position the coupling pin 26 is located at one end of the coupling slot 54 and the cam pin 24 is located at the end of the cam slot 56 adjacent the coupling slot 54. As the lock nut 22 is rotated the cam pin 24 is moved to the distal end of the cam slot and the position of the coupling pin 26 moves along the coupling slot to the mid-point. Further rotation of the lock nut causes the cam pin to move away from the distal end of the cam slot, back towards the coupling slot and the position of the coupling pin 26 moves further along the coupling slot towards the other end. In the closed position the cam pin 24 is back at its starting position within the cam slot 56, adjacent the coupling slot 54, and the coupling pin is located at the opposite end of the coupling slot to where it started.
While the present embodiment uses a particular cam based actuator to control the linear position of the reciprocating element 20, it will be appreciated that other structures for controlling the linear position of the reciprocating element 20 could be used instead.
The case latch assembly 10 is further provided with a number of fixing rivets 46.
The reciprocating element 20 is reciprocally linearly moveable between a closed position in which the strike plate hook 44 may engage with the strike plate member 18, through the strike plate aperture 28, and an open position in which the strike plate hook 44 is separated from the strike plate member 18. When the reciprocating element 20 is in the closed position and the strike plate hook 44 is engaged with the strike plate member 18, the first 12 and second 14 mounting dishes are brought into a generally adjacent arrangement and are locked together.
The reciprocating element 20 further comprises a cantilever portion 20b such that the cantilever portion extends towards the second mounting dish 14. The cantilever portion 20b extends away from the main body of the reciprocating element 20 in a direction generally towards the second mounting dish 14 and away from the strike plate hook 44. The cantilever portion 20b defines a first sloped part which is angled away from the main, planar, region of the reciprocating element 20 towards the second mounting dish 14, a second planar part which is substantially parallel to the main, planar, region of the reciprocating element 20, and a third sloped part which is angled away from the second mounting dish 14 back towards the plane of the main body of the reciprocating element 20. The first sloped part of the cantilever portion 20b
A ramp insert 50 is provided which is fixed to the second lock mounting part 14 by a fixing rivet 54 and a stud (not shown) on the base of the ramp insert 50 which engages with the hole 58 of the second lock mounting part 14. The ramp insert 50 is also trapped in place by the mounting element 30 when the mounting element 30 is fixed to the second lock mounting part 14. The ramp insert 50 provides a ramp 52 defining a constraining formation over which a part of the cantilever portion 20b of the reciprocating element 20 moves, as well as providing a protective end cap for the mounting element 30. While most components of the case latch assembly 10 may typically be made of metal, the ramp insert 50 is typically made of plastic. This results is a quieter and smoother operation as the case latch assembly 10 is opened and closed and the cantilever portion 20b of the reciprocating element 20 moves against the ramp 52. One problem with the plastic insert is that it may perish, or wear more quickly than the metal components which form the majority of the case latch assembly. It will be appreciated that if the ramp insert 50 fails then the latch may not close properly. In order to address this problem and permit the latch to continue to function adequately if the ramp insert 50 should fail, the rivet 54 which serves to secure the ramp insert 50 in place is shaped and positioned to act as a ramp in the event that the ramp insert 50 fails. A washer 56 raises the rivet 54 to the correct height to achieve this function. In some examples, one or more rivets alone might be used rather than employing a plastic ramp.
The cantilever portion 20b and the ramp 52 are arranged such that as the reciprocating element 20 is retracted on the hinge member 16 towards the closed position, the cantilever portion 20b rides up the ramp 52 and acts against the torsional bias provided by the springs 32a, 32b, causing rotation of the hinge member 16 and resultingly the reciprocating member 20 about the mounting hook (pivot) 34, and thus the strike plate engagement portion 20a to deflect (rotate) down towards the strike plate member 18. Similarly, when the reciprocating element 20 is extended on the hinge member 16 towards the open position, the cantilever portion 20b drops down the ramp 52, permitting the torsion applied by the springs 32a, 32b to rotate the hinge member 16 and resultingly the reciprocating member 20 about the mounting hook (pivot) 34, and thus the strike plate engagement portion 20a to move up and away from the strike plate member 18.
It will be appreciated that the path of movement (movement profile) of the strike plate engagement portion and specifically the hook 44 can effectively be specified by selecting the shape and/or position of the cantilever portion 20b and/or the ramp 52.
In the example of
The cantilever portion 20b is arranged such that it is substantially at the top of the ramp 52 when the strike plate engagement portion 20b is in engagement with the strike plate member 18. The cantilever portion 20b is further arranged such that when the reciprocating element 20 is moved from the closed position towards the open position the cantilever portion 20b descends the ramp 52 to allow the torsion applied by the torsion springs 32a, 32b to bias the strike plate engagement member away from the second mounting dish 14.
The cantilever portion 20b of the reciprocating element 20 extends behind the pivot point of the springs 32a, 32b and the mounting hook 34. Similarly, the ramp insert 50 is provided substantially behind the pivot point of the springs 32a, 32b and the mounting hook 34. In other words, the cantilever portion 20b (and preferably, if present, the ramp) extends to the side of the pivot furthest from the first lock mounting part. By providing these structures behind the hinge member 16 and the main bulk of the reciprocating element 20 and the cam-based actuation structure (rather than underneath them) the case latch assembly can have a slimmer profile.
Referring first to
In
In
In
To open the latch, the reverse process occurs. In particular, as the reciprocating element is extended from its position in
Referring to
| Number | Date | Country | Kind |
|---|---|---|---|
| 14155507.8 | Feb 2014 | EP | regional |
This application is a Continuation of co-pending application Ser. No. 14/245,243 filed on 4 Apr. 2014, for which priority is claimed under 35 U.S.C. §120; and this application claims priority of Application No. 14155507.8 filed in EUROPE on 18 Feb. 2014 under 35 U.S.C. §119, the entire contents of all of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14245243 | Apr 2014 | US |
| Child | 15139795 | US |
