Movement control device

Abstract

The movement control device 10 for damping a push latch in an opening direction comprises: a base housing 12; a damper housing 16 and a piston 20. The piston and damper housing are located within the

Description

Field of the Invention The present invention relates to movement control devices, and particularly, although not exclusively, for furniture components such as drawers and doors. Background One type of movement control device is a push latch. Such devices are generally fitted to doors and drawers of furniture items. In use, an operator would push the drawer or door, hence actioning a push rod located within the push latch. The push latch thus opens the door or drawer by a small amount to allow the operator to be able to fit their fingers behind the drawer or door and complete the opening operation. Such push latches are popular because they negate the need for a handle to be included on the outer surface of the drawer / door. US5518223 Al provides a damped pushed latch. The present arrangement seeks advancements over this arrangement. Particularly, it is desirable to minimize the length of a push latch to allow such to be mounted in or on cabinets / units without effecting the structural integrity of the cabinet / unit. WO2021 / 233657 Al shows another known arrangement. Summary of the Invention The present invention provides a push latch of reduced length with a damper housing, indexing mechanism and a spring essentially co-axially aligned. The present arrangement provides a movement control device for damping applications such as furniture doors, sliding doors, drawers, lifters, etc. in the opening direction door, etc. Typically, although not essentially, at least part of the index mechanism is provided within an inner diameter of the spring. According to the present invention there is provided a movement control device for damping a push latch in the opening direction, the device comprising: a base housing; a damper comprising a damper housing and a piston assembly operable to be housed in said base housing, wherein one of said damper housing and said piston assembly is fixed relative to the base housing, and the other of said damper housing and piston assembly is moveable with respect to the base housing between a first position and a second position; a spring operable to bias the moveable one of the damper housing or piston assembly in the first position; an indexing mechanism operable to maintain the moveable one of the damper housing or piston assembly in the second position; wherein, the indexing mechanism comprises a moveablely mounted pin, and the movement control device comprises means to limit the range of the pin. Preferably, the base housing comprises a substantially cylindrical body, and wherein the damper housing, spring and index mechanism are substantially co-axial within said cylindrical body. Generally, it preferred that the base housing is operable to fit within pre-drilled holes of approximately 10mm. It is preferred that at least a portion of the indexing mechanism is located at least partially with spring. Preferably the spring is located within the damper housing. However, embodiments whereby the spring is located within the base housing, and outside of the damper housing are also contemplated. Preferably the indexing mechanism comprises a pin and a track. It is preferred, in some embodiments that one of the pin or the track is maintained, at least partially, within the spring. It is preferred that the damper housing comprises a first plug, and said track is affixed thereto. The track could be made integral therewith, or be made of a separate piece, and affixed to the plug. It is preferred that the damper is a linear damper. Such a damper will typically comprise a piston and a piston rod. Collectively, the piston and piston rod may be termed the piston assembly. Preferably the pin is positioned substantially in parallel with the spring and the piston rod. The track of the indexing mechanism is ideally co-axial with the spring and the damper. The pin is preferably mounted off-centre with respect to the piston rod. Preferably the piston comprises means to prevent rotation with respect to the base housing. It is also preferred the damper housing comprises means to prevent rotation with respect to the base housing. Preferably means to limit the range of the pin operates in a plurality of directions. In order that the present invention be more readily understood specific embodiments will now be described with reference to the accompanying drawings. Description of drawings Figure 1 shows a push latch in cross-section with a damper housing in a second position with respect to a base housing. Figure 2 shows a push latch in cross-section with a damper housing in a first position with respect to a base housing. Figure 3 shows a close-up of a piston arrangement of the push latch of figures 1 and 2. Figure 4 shows a close-up of a plug of the damper housing of the push latch of figures 1 and 2. Figure 5 showsan example of the push latch of figures 1 and 2 being placed in situ in an aperture of a unit. Figure 6 shows the push latch of figure 5, with the unit and base housing removed. Figure 7 shows an alternative base housing for the push latch. Figure 8 is a push latch according to a second embodiment. Figure 9 shows the damper housing of the push latch of figure 8. Figure 10 shows a push latch in cross-section of a third embodiment, with the push latch being in the first position. Figure 11 shows a push latch in cross-section according to a fourth embodiment, with the push latch being in the second position, noting that the base housing is note shown. Figure 12 shows a close-up of a piston of the fourth embodiment. Description of Preferred embodiments The present arrangement looks to provide a push latch of reduced length compared to known arrangements. The present embodiments provide a push latch to be fitted to doors and drawers of furniture items. In use, an operator pushes the drawer or door, hence actioning the push latch. The push latch thus opens the door or drawer by a small amount to allow the operator to be able to fit their fingers behind the drawer or door and complete the opening operation. The damping action on the embodiments of the present invention work on the opening stroke of the push latch: in other words when the door or drawer is being opened. The present arrangement looks to provide a push-latch that is minimized to an extent that it can be inserted into a (typically) pre-drilled hole inside a cabinet carcass, or the like. So that this is feasible, the hole cannot be too deep, as the structural integrity of the cabinet may be compromised. Typically, the diameter of the aperture would be 10mm. The present arrangement adds a damping function to a push latch during the opening stroke of the damper. Broadly, the push-latch 10 is shown in figure 5. There is a base housing 12. The base housing 12 is dimensioned to fit within a hole within a cabinet C. A dedicated fitment 14 may alternatively be used, as shown in figure 7. Figure 6 shows a view of the push latch of figure 5 with the base housing 12 removed. A damper housing 16 is operable to move in a reciprocal manner along the primary axis of the base housing. An adjustable end piece 218 is provided to allow for fine adjustment of the positioning of the push latch 10. The push latch is shown in more depth in figures 1 to 4. Figure 1 shows a push latch in cross-section with a damper housing in a second position with respect to a base housing, whilst figure 2 shows a push latch in cross-section with a damper housing in a first position with respect to a base housing. Figure 1 shows the damper housing 16 that is slidably co-axially mounted within the base housing 12. The damper housing 16 is sealed at a first end by plug 18, and at a second end by plug 200. The second end plug 200 may also be termed the bottom plug 200. Damping fluid is contained therewithin. A piston 20 is shown in detail in figure 3. The piston 20 is also visible in figures 1 and 2 (noting that it is orientated the other way around). An O-ring 22 is fitted on the piston 20. A piston rod 24 is connected to the piston 20, and to the base housing at point 26. The piston 20 and O-ring 22 are formed to resist the flow of damping fluid in one direction, and to more easily allow damping fluid to pass in the other. Such arrangements are known in the field of linear dampers. The piston 20 and piston rod 24 are fixed with respect to the base housing. Plug 18 of damper housing 16 comprises an aperture through which the piston rod 24 passes. Appropriate sealing is provided to ensure that the damping fluid is retained within the damper housing 16. In use the damper housing 16 is operable to slide co-axially with the base housing 12, thus there is relative movement between the piston 20 and the damper housing 16. Accordingly, during the working stroke of the push latch 10, the damping fluid is operable to be moved from one side of the piston 20 to the other. Accordingly, a damping action is provided as is known in linear dampers. However, it should be appreciated that the working stroke of the push latch of the present embodiment is in the opening direction of a door of a piece of furniture. Figure 3 shows the piston 20 in close-up. The piston comprises an elongate body comprising a volume compensator 28 and mounting section 30. The piston comprises fins 32 that are operable to cooperate with grooves on the inner diameter of the base housing 12 to prevent relative rotation of the piston 20 with the base housing 12. A spring 38 is mounted within the damper housing 16. Unhindered, the spring 38 urges the damper housing into the first position (i.e., the position shown in figure 2). One end of the spring abuts the (fixed) piston 20, and hence urges the damper housing into the position shown in figure 2. The push latch 10 further comprises an indexing mechanism. The indexing mechanism comprises a latch, and a track 36. The latch is typically a cylindrical rod bent into a C shape, thus creating a C pin 34. Advantageously, the track 36 can be made integrally with the plug 200. However, it may be made as a separate item. Prior patent application (EP4153829) by the present applicant describes the works of a similar indexing mechanism, the contents of which are hereby incorporated by reference. The pin 34 is pivotally mounted on mounting section 30. Restraining means 40 and 42 limit the scope of movement of the pin 34. Restraining means 40 limits the rotation in a notionally horizontal direction, whilst means 42 limited a notionally vertical direction. Such restraints ensure that the pin 34 centers to the track 36 for engagement therewith. When the damper housing 16 is urged into the base housing 12, the pin will come into contact with the track 36. The configuration of the camming surfaces of the track 36 are such that the pin will follow path X. The pin will come to rest at point Y, thus locking the damper housing 16 in position with respect to the piston 20, and hence the base housing 12. Pushing on the push latch 10 will cause the pin 34 to follow the path Z, and hence release the damper housing. Under the action of the spring 38 the damper housing 16 will revert to the first position, as shown in figure 2. It will be appreciated that, during the working stroke of the push latch the damping fluid is urged from one side of the piston to the other. In figure 1, the damping fluid is on the left side of the piston as viewed. In figure 2, the damping fluid is on the right side of the piston. Thus, if an oil is used, the spring 38, pin 34, track 36 are all lubricated, thus prolonging use. By locating the indexing mechanism at least partially within the internal diameter of the spring 38, the length of the push latch 10 can be reduced. Accordingly, it becomes feasible to manufacture a push latch that is operable to fit within a pre-drilled hole within a furniture carcass. The pin 34 is partially maintained within the spring at all times. Particularly, in the second position the pin is at least partially within the spring. The pin is maintained wholly within the spring when the damper housing is in the first position. The spring 38, the track of the indexing mechanism 36 and damper housing 16 are all co-axially aligned. The pin 34 of the indexing mechanism is mounted parallel to the central axis of the spring 38 and the piston rod 24. The pin 34 is mounted off-center to allow engagement with the track 36. However, the indexing mechanism is essentially co-axial with the damper housing 16 and the spring 38. Accordingly, the push latch can be made smaller in length, and have a reduced width. The coaxial alignment of the above features also makes it possible to manufacture the push latch 10 to have a substantially cylindrical shape. As such, the push latch can be readily inserted into holes drilled within furniture carcasses. By placing the track 36 of the indexing mechanism inside the damper housing, the track is kept free from debris, and hence maintains working life of the push latch. A second embodiment is shown in figures 8 and 9. Here, the spring 38 and indexing mechanism are mount outside of the damper housing 16. However, the spring, damper housing and indexing mechanism are all substantially mounted co-axially. Particularly, the spring, damper housing and track of the indexing mechanism are mounted co-axially. The pin 34 of the indexing mechanism is mounted in parallel with the spring and the piston rod, positioned off-center thereto. In the second embodiment the track 36 of the indexing mechanism is always at least partially maintained within the inner diameter of the spring 38. The action of the damper works in the same manner as in the first embodiment. Other features described in relation to the first embodiment, such as the means to limit the movement of the pin 34, and the means to ensure that there is minimal rotation of the respective comments are equally applicable to the second embodiment. In both the first and second embodiments the tip of the damper housing that is exposed from the base housing may comprise an adjustable member to aid in fine tuning the positioning of the push latch. Fig.10 shows a push latch in cross-section in accordance with a third embodiment. Here, the piston assembly is in the first position with respect to a base housing. In this embodiment it is the piston assembly that moves with respect to the base housing, with the damper housing remaining stationary. A cap A is provided at the end of the piston rod. Cap A is operable to slide between the base housing 12 and the damper housing 16. The adjustable end piece 218 is fixedly attached to the base housing 12. Cap A is operable to be rotated, thus allowing for fine-tuning adjustments. Alternative indexing mechanisms may be used. For example, the rotational mechanism as disclosed in EP 2147179 may be used. Such an embodiment is shown in Fig 11 and 12. In this embodiment, the rotational pin 34' is guided in the track 36', 36". The damper could be a fluid damper with a piston and O-ring arrangement. Alternatively, as shown in the drawings, a frictional piston and O-ring arrangement may be used. In case of a frictional piston and O-ring design, a frustro-conical shaped expander 220 is operable to urge against the O-ring produce a higher friction in the opening direction. A ring expandable in the circumferential direction could also be used. A flat-faced piston ring 20 urges the O-ring back in the closing direction, hence providing a lower friction in the closing direction. A push latch piston could also be designed as an air damper as disclosed in epl717396. The contents of which are hereby incorporated by reference. It is to be understood that the embodiments described herein are for reference purposes only, and that the scope of the invention is to be determined by the appended claims. Many modifications and variations are possible within the scope and spirit of the invention. For example, in the push latch shown in fig.8, the spring 38 could instead be mounted in the base housing 12 in the damper housing 16. In this case, the track 36 of the indexing mechanism would not be inside the spring 38 but would still be co-axially therewith. The pin 34 would still be circumferentially off-center of the piston rod, but parallel to both the spring and the piston rod.

Claims

1. A movement control device for damping a push latch in the opening direction, the device comprising: a base housing;a damper comprising a damper housing and a piston assembly operable to be housed in said base housing, wherein one of said damper housing and said piston assembly is fixed relative to the base housing, and the other of said damper housing and piston assembly is moveable with respect to the base housing between a first position and a second position;a spring operable to bias the moveable one of the damper housing or piston assembly in the first position;an indexing mechanism operable to maintain the moveable one of the damper housing or piston assembly in the second position;wherein, the indexing mechanism comprises a moveable mounted pin, and the movement control device comprises means to limit the range of the pin.

2. A movement control device according to claim 1, wherein the base housing comprises a substantially cylindrical body, and wherein the damper housing, spring and index mechanism are substantially coaxial within said cylindrical body.

3. A movement control device according to either claim 1 or claim 2, wherein at least a portion of the indexing mechanism is located at least partially within the spring.

4. A movement control device according to any of claims 1 to 3, wherein the spring is located within the damper housing.

5. A movement control device according to any of claims 1 to 3, wherein the spring is located within the base housing, and outside of the damper housing.

6. A movement control device according to any preceding claim, wherein the indexing mechanism comprises a pin and a track.

7. A movement control device according to claim 6, wherein one of the pin or the track is maintained, at least partially, within the spring.

8. A movement control device according to either claim 6 or 7, wherein the damper housing comprises a first plug, and said track is affixed thereto.

9. A movement control device according to any of claims 6 to 8, wherein the pin is positioned substantially in parallel with the spring.

10. A movement control device according to any preceding claim, wherein the damper is a linear damper.

11. A movement control device according to any preceding claim, wherein the piston comprises means to prevent rotation with respect to the base housing.

12. A movement control device according to any preceding claim, wherein the damper housing comprises means to prevent rotation with respect to the base housing.

13. A movement control device according to any preceding claim, wherein the pin is directly or indirectly attached to the piston.

14. A movement control device according to claim 13, wherein the piston, pin and the track are inside the damper housing.

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