RESILIENT BIASED LATCH WITH FUSIBLE RETAINING MEMBER
A device containing a retaining mechanism comprising: a resiliently biased latch member adapted for motion between at least three positions; a fusible retaining member having at least one engagement surface configured to engage with and act as a stop to the motion of the latch member between two of said positions; and a heating member positioned adjacent to the retaining member; wherein one motion of the latch member between said positions causes it to engage with the fusible retaining member and stop said motion, and activation of the heating member affects at least a portion of the fusible retaining member causing it to soften, melt, weaken or break allowing the latch member to move so as to release the latch member for a further motion between said positions
1 . A device containing a retaining mechanism comprising:
a resiliently biased latch member adapted for motion between at least three positions;
a fusible retaining member having at least one engagement surface configured to engage with and act as a stop to the motion of the latch member between two of said positions; and
a heating member positioned adjacent to the retaining member;
wherein one motion of the latch member between said positions causes it to engage with the fusible retaining member and stop said motion, and activation of the heating member affects at least a portion of the fusible retaining member causing it to soften, melt, weaken or break allowing the latch member to move so as to release the latch member for a further motion between said positions.
2 . The device according to claim 1 , wherein the engagement surface is sloped such that the engagement between the engagement surface and the latch member presses the retaining member towards the heating member.
3 . The device according to claim 1 or 2 , wherein the latch member comprises a sloped engagement surface such that the engagement between the engagement surface of the retaining member and the latch member presses the retaining member towards the heating member.
4 . The device according to any of the preceding claims, wherein the retaining member has a softening or melting temperature of between 40° C. and 150° C.
5 . The device according to any of the preceding claims, wherein the retaining member comprises polycaprolactone or a cyclic/cyclo olefin polymer or copolymer.
6 . The device according to any of the preceding claims, wherein the heating member is an element of a printed circuit board (PCB).
7 . The device according to any of the preceding claims, further comprising a temperature sensor, such as a temperature sensor in thermal contact with the PCB of claim 6 .
8 . The device according to any of the preceding claims, in which the device is adapted to affect the fusible retaining member, thereby to release the latch member, after a controlled period.
9 . The device according to claim 8 , wherein the controlled period begins after the engagement of the latch member and the fusible retaining member and/or a predetermined time after activation of the heating member.
10 . The device according to any of the preceding claims, wherein release of the latch member releases stored mechanical energy, for example stored mechanical energy in a preloaded biasing means such as a mechanical spring, e.g. a torsion spring.
11 . The device according to any of the preceding claim, wherein the retaining mechanism temporarily interrupts the operation of a drive means
12 . The device according to any of the preceding claims, wherein release of the latch member causes a drive means to transfer a liquid.
13 . The device according to claim 11 or 12 , wherein the drive means transfers the liquid between different zones in the device.
14 . The device according to claim 11 or 12 , wherein the drive means transfers the liquid out of the device.
15 . The device according to any of the preceding claims, wherein the retaining member is configured to engage with a casing or chassis element of the device.
16 . The device according to any of the preceding claims, which is a medical device such as a diagnostic test device.
17 . A mechanism for a device, such as a medical device, the mechanism being electromechanical and comprising:
a resiliently biased, rotary latch member having a plane of rotary motion and an axis perpendicular thereto;
a fusible retaining member having at least one engagement surface configured to engage with and act as a stop to rotary motion of the rotary latch member; and
a heating member positioned adjacent the retaining member,
wherein activation of the heating member affects at least a portion of the fusible retaining member causing it to soften, melt, weaken or break and so allowing the rotary latch member to move in at least the direction of the axis so as to release the rotary latch member for rotary motion.