Latch assembly

Abstract: A latch assembly for latching two components (1,2) comprising a support member (3) arranged to be attached, in use, to a first component (1) to be latched. A lever member (4) is pivotally attached to the support member (3) at a first pivot point (5), and an engaging member (6) is pivotally attached to the support member at a second pivot point (7). The engaging member (6) is arranged to be moved, by movement of the lever member (4), from a position in which it urges a second component (2) out of engagement with the first component (1) to a position in which it engages with a second component to be latched to draw the second component into engagement with the first component and latch the components (1,2).

Description: There are many applications in which it is required to latch two components into engagement with one another. In many such applications it is difficult for a user carrying out the latching to assert sufficient force to ensure sufficient engagement or dis-engagement of the two components for the required purpose. A good example of such a situation is the latching of an electrical circuit board to a housing, in which it is required that, when the board and housing are in engagement, the engagement be such that good electrical contact is made between the board and the housing. Given that, in many situations, such components are in a confined region with restricted access, it is difficult for a user to ensure good engagement unless force is applied to sections of the board or housing that are not designed to withstand such force. Furthermore, once such components are in engagement, it is often very difficult to remove them from engagement with one another without, again, requiring force to be applied to regions that are not designed to receive such force. US-A-4230351 discloses a lever assembly with pivotal engaging member and driving spring. EP-A-0 034 356 discloses a lever assembly with pivotable lever arm. US-A-2129926 discloses a lever assembly with biasing spring. According to the present invention there is provided a latch assembly for latching two components, the assembly comprising: a support member arranged to be attached, in use, to a first component to be latched; a lever member pivotally attached to the support member at a first pivot point; and an engaging member pivotally attached to the support member at a second pivot point and arranged to be moved, by movement of the lever member, from a position in which it urges a second component out of engagement with the first component to a position in which it engages with the second component to be latched to draw the second component into engagement with the first component and latch the components; characterised in that: the first pivot point is closer than the second pivot point to the engaging surface of the engaging member. The engaging member may have a pin or slot formed therein, the pin or slot engaging, in use, with a slot or pin on the lever member. If a slot and pin arrangement is provided the position of the slot and pin relative to the first and second pivot points may be selected such that, when the latch assembly is in a latched position, the latch is biased to remain in that position. The lever member may be arranged so that it can be folded into a storage position. One example of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a side view of a latch assembly according to an example of the present invention in an engaged and latched position; Figure 2 is a side view of the latch assembly of figure 1 in an unlatched dis-engaging position; Figure 3 is a plan view of the latch assembly of figure 1; and Figure 4A and 4B are plan and side views of a second example of the present invention in an engaged latched position. Referring to figure 1, a support block 3 for a latch assembly according to the invention is attached to a first component 1 which is to be latched to a second component 2. Pivotally supported on the support block 3 is a lever member 4. The lever member 4 is pivotally supported upon the support block 3 by pins 5. Also pivotally attached to the support block 3 is an engaging member 6. The engaging member 6 is pivotally attached to the support block 3 by a pin 7. An engaging portion 8 is formed on one end of the engaging member 6. A slot or slots 9 are formed in the lever member 4 and a pin or pins 10, attached to engaging member 6, are retained therein. In operation, the latch assembly is initially in unlatched position (Figure 2) and a user pivots the lever member 4. The retaining slots 9 in the lever member 4 pivot the engaging member 6 via the pins 10. The engaging portion 8 of the engaging member 6 engages with the second component to be latched 2. The second component to be latched 2 is then drawn into engagement with the first component to be latched 1. The lever member 4 can finally be pivoted no further and is biased into the latch position by the relative positions of the pins 5, 7 and pin and slot arrangement 9,10. When dis-engaging the two components to be latched 1,2, the lever member 4 is pivoted in the opposite direction and a further section of the engaging portion 8 urges the two components 1,2 out of engagement. Figure 4 shows a second example of the present invention, in which components correspond to those in the example of figure 1 have identical numbering. In this example, the lever member 4 is arranged so that it has a releasable latch 11 formed thereon. The lever member 4 is formed from two components pivotally attached to one another by a pin 12. The releasable latch 11 allows the lever member to be folded around the pin 12 when the releasable latch 11 is activated. This means that, when the latch is in a latched position, the lever member 4 can be moved into a position in which it does not impinge upon anything attached to the surface of the first component 1. The present invention, whilst enabling strong and reliable latching of two components, also allows for simple dis-engagement of the two components when required. Furthermore, it has a minimum number of simple components, making it cheap and easy to manufacture. In addition, it has a low profile which means that a series of latched components can be stacked one upon another in close relationship.

Claims: A latch assembly for latching two components, the assembly comprising: a support member (3) arranged to be attached, in use, to a first component (1) to be latched; a lever member (4) pivotally attached to the support member at a first pivot point; and an engaging member (6) pivotally attached to the support member at a second pivot point (7) and arranged to be moved, by movement of the lever member, from a position in which it urges a second component out of engagement with the first component to a position in which it engages with the second component to be latched to draw the second component into engagement with the first component and latch the components; characterised in that : the first pivot point (5) is closer than the second pivot point (7) to the engaging surface of the engaging member (6). An assembly according to claim 1, wherein the engaging member (6) has a pin or slot formed therein, the pin or slot engaging, in use, with a slot or pin on the lever member (4). An assembly according to claim 2, wherein the position of the slot and pin relative to the first and second pivot points (5, 7) may be selected such that, when the latch assembly is in a latched position, the latch is biased to remain in that position. An assembly according to any preceding claim, wherein the lever member (4) is arranged so that it can be folded into a storage position.

Inventors: LAMBERT ANTHONY, LAMBERT, ANTHONY
Applicants: MCKECHNIE SPECIALIST PRODUCTS, MCKECHNIE SPECIALIST PRODUCTS LIMITED
Application year: 1998
Main classification: E05C3
IPC codes: E05C3, H05K7, E05B17