Motion control device

Abstract

A motion control device includes a housing in which an elongated push rod is mounted for reciprocating motion along a longitudinal axis between a first position and a second position, wherein the push rod extends out of the housing in both the first position and the second position. A spring is also disposed in the housing, the spring including a spindle operable to provide a biasing force on the push rod. A damping device including a spindle is disposed in the housing, wherein the damping device is continuously engaged with the push rod by reciprocating motion of the push rod. The spindle of the spring and the spindle of the damping device are not coaxial.

Description

Technical Field

[0001] The present invention relates to motion control devices and in particular, but not exclusively, to motion control devices for furniture components such as drawers and doors. Background Art

[0002] The disclosed arrangement is intended to provide a more stable product while minimizing overall size and improving usability.

[0003] One type of motion control device is a push latch. This device is commonly installed on doors and drawers of furniture items. In use, the operator pushes on the drawer or door, which activates a push rod located in the push latch. The push latch then opens the door or drawer slightly, allowing the operator to place a finger behind the drawer or door and complete the opening operation. This push latch is popular because it does not require a handle to be installed on the outer surface of the drawer / door.

[0004] However, there are various problems with the known arrangements. These problems include being too large. It will be appreciated that storage space within the drawer may be limited. It is desirable that the push latch not encroach too much on space.

[0005] Additionally, some push latches operate violently during the initial opening phase, causing the door / drawer to open rapidly.

[0006] As the door impacts the motion control, lateral forces can act on the push rod and damper, causing friction that can have a detrimental effect on operation. This can be particularly prevalent on shorter doors, which require a greater opening angle from the motion control to function properly. Or, in other words, shorter doors abut the push rod at a wider angle.

[0007] The arrangements of the present disclosure are directed to addressing these and other issues. Summary of the invention

[0008] According to the present invention, a motion control device is provided, comprising: a housing; an elongated push rod mounted in the housing for reciprocating motion along a longitudinal axis between a first position and a second position, wherein the push rod extends out of the housing in both the first position and the second position; a spring comprising a main shaft operable to provide a biasing force on the push rod; and a damping device comprising a main shaft, wherein the damping device is in substantially continuous engagement with the push rod directly or indirectly through reciprocating motion of the push rod, wherein the main shaft of the spring and the main shaft of the damping device are not coaxial.

[0009] The advantage of the arrangement of the present invention is that the damping means is operable to act on the push rod by the extent of travel of the push rod. By making one of the spring or damping means coaxial with the push rod and mounting the other of the spring or damping means to one side of the push rod, the damping means can be kept to a minimum length.

[0010] Preferably, the motion control means comprises an indexing mechanism for controlling the movement of the push rod relative to the housing.

[0011] Preferably, the indexing mechanism is operable to maintain the push rod in the first position or the second position.

[0012] The damping device may be a linear damper. The damper may be a piston and cylinder type damper. Preferably, the damper provides a decreasing force over its working stroke. The force of the spring decreases as it extends, so it is desirable to reduce the damping force accordingly to allow a substantially constant force to act on the drawer or door throughout the working stroke of the motion control device. Accordingly, preferably, the damping force has a decreasing force characteristic.

[0013] It will be appreciated that the damper may alternatively generate damping resistance at a constant rate over its operating stroke.

[0014] In one embodiment, preferably, the main axis of the damping device is coaxial with the longitudinal axis of the push rod.

[0015] Preferably, the damping device is at least partially contained within the push rod. Typically, the push rod will include a hollow core that can accommodate the damper. Particularly preferably, the push rod utilizes its hollow core as a damper housing. This arrangement reduces the size of the motion control device. In a preferred arrangement, the piston of the damper is assembled in the bore of the push rod together with the damping fluid.

[0016] Preferably, the piston of the damper is movable relative to the push rod. When the push rod is actuated, the piston forces the damping fluid to flow from the first chamber to the second chamber, thereby causing a damping action.

[0017] The damping device may be provided as a separate unit which is inserted into a hollow core of the damping device.

[0018] Preferably, in some embodiments, the major axis of the spring is substantially parallel to the longitudinal axis of the push rod.

[0019] The push rod may include a flange. In this arrangement, the spring may be held between the flange and the housing. Accordingly, the spring is arranged to one side of the push rod, with the major axis of the spring and the major axis of the push rod being substantially parallel. Accordingly, the spring is operable to push the flange to move the push rod from the first position to the second position. By arranging the spring outside the longitudinal axis of the push rod, the damping device is allowed to be shorter.

[0020] In an alternative embodiment, the spring may be mounted at least partially within the push rod. Typically, the push rod includes a hollow core operable to accommodate the spring. In this embodiment, the damping device may be mounted to one side of the push rod in the housing. In a similar manner to the first embodiment, by arranging the damper outside the longitudinal axis of the push rod, the damping device is allowed to be shorter.

[0021] The damping device may be pivotally mounted in the housing. The mounting may be arranged such that movement of the push rod causes rotational movement of the damping device. In a preferred arrangement, the push rod includes a flange operable to engage the damping device such that when the push rod moves from the first position to the second position, the main axis of the damping device is caused to rotate relative to the longitudinal axis of the push rod.

[0022] The spring is typically a compression spring. As the spring stretches, it will exert less force on its path of travel. However, as the flange moves further away from the pivot, the flange exerts a greater force on the damper. Assuming that moment is force times distance, as the spring force decreases, the distance increases, so that a substantially uniform damping force is ultimately provided. Of course, the settings can be customized to produce a variety of different damping characteristics as desired.

[0023] When the push rod is in the first position, the major axis of the damping device and the longitudinal axis of the push rod may define an acute angle.When the push rod is in the second position, the major axis of the damping device and the longitudinal axis of the push rod may be substantially parallel.

[0024] The damper may be retained within a casing, the casing being mounted for pivotal movement. At least one of the damper housing or the damper piston may slide relative to the casing.

[0025] According to a second aspect of the present invention, a push latch is provided, comprising: a push rod, which is installed to move between a first position and a second position together with a housing; a spring, which is operable to push the push rod from the first position to the second position, wherein the spring is installed to be substantially parallel to the push rod but not coaxial with the push rod, wherein the push rod also includes a damping device, which directly or indirectly engages with the push rod during the entire travel of the push rod between the first position and the second position.

[0026] According to a third aspect of the present invention, a push latch is provided, comprising: a push rod, which is installed to move between a first position and a second position together with a shell; a damping device, which is installed in the shell, wherein when the push rod is in the first position, the main axis of the damping device defines an acute angle with the push rod, and when the push rod is in the second position, the main axis of the damping device is parallel to the push rod.

[0027] In the third aspect, the damper may be held in a casing that is pivotally mounted in the housing. At least one of the damper housing and the damper piston rod may be slidably mounted within the casing.

[0028] In the second and third aspects, the push latch preferably includes an indexing mechanism for controlling movement of the push rod relative to the housing.

[0029] Preferably, the indexing mechanism is operable to maintain the push rod in the first position or the second position.

[0030] The damping device may be a linear damper. The damper may be a piston and cylinder type damper. The damper may produce a decreasing force over its working stroke, or in an alternative embodiment, the damper may produce a damping resistance at a constant rate over its working stroke. As the spring is deployed from a fully compressed position to a fully extended position, the spring will provide a gradually decreasing force. Accordingly, it is advantageous for the damping device to provide a correspondingly decreasing damping force so that the damper and spring cooperate to provide a substantially constant opening force.

[0031] In all aspects, the housing is engageable with a base plate. Preferably, the housing is releasably detachable from the base plate. Typically, the base plate is mounted to the item of furniture and the motion control device is mounted on the base plate. A mechanism is provided to enable the motion control device to be forcibly removed in the event of a severe impact (e.g. when a door or drawer is slammed shut) to prevent damage to the device. Reattachment of the motion control device is a simple matter.

[0032] Preferably, the housing and base each include complementary noses that clip together with a resistance adapter. Preferably, the noses are angled to assist in connection and release of the housing from the base.

[0033] Particularly preferably, the housing is forced to be detached from the base plate during an excessive transverse force in a direction substantially perpendicular to the longitudinal axis of the push rod.

[0034] In order to more easily understand the present invention, specific embodiments of the present invention will now be described in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Fig. 1 shows a perspective view of a motion control device according to a first embodiment. The housing is shown separately so that the push rod installed therein can be seen.

[0036] Fig. 2 shows a perspective view of the push rod. The view in this figure has been rotated 180° relative to the view in Fig. 1 .

[0037] Figure 3 shows the mounting plate.

[0038] FIG. 4 shows the lower part of the housing with the push rod removed.

[0039] Figure 5 shows a first cross section of the motion control device according to the first embodiment. The push rod is in the position where it normally is when the cabinet door is closed.

[0040] FIG. 6 shows a second cross-section of the motion control device according to the first embodiment.

[0041] Figure 7 shows a first cross section of a motion control device according to a first embodiment. The push rod is in the position where it would normally be when the cabinet door is open. A sample of the cabinet and door is shown as background.

[0042] Figure 8 A perspective view of a motion control device according to a second embodiment is shown. The housing is shown separately so that the push rod installed therein can be seen.

[0043] Fig. 9 A plan view of a motion control device is shown with a push rod in a retracted position according to a second embodiment.

[0044] Fig.10 A plan view of a motion control device is shown with a push rod in an extended position according to a second embodiment.

[0045] Figures 11 to 15 The operation of the indexing mechanism which may be incorporated into the first and second embodiments is shown. DETAILED DESCRIPTION

[0046] FIG1 shows a motion control device commonly referred to as a touch latch. Touch latches are commonly used in furniture applications to assist in controlling the movement of components such as drawers and doors. In particular, the touch latch facilitates the opening and closing of these components by simply pushing these components in a known manner.

[0047] A first embodiment is described with reference to FIGS. 1 to 7 . The motion control device comprises a housing 10 . In FIG. 1 , the housing is shown as being separated, having a top portion 10 a and a bottom portion 10 b. A push rod 12 is mounted for reciprocating motion within the housing 10 . As shown in FIG. 2 , the push rod comprises a hollow bore 14 . The bore 14 extends substantially throughout the length of the push rod 12 . Accordingly, the push rod 12 itself can serve as a housing for a damper 16 . The damping device 16 is typically a linear damper of the piston and cylinder type. The damping device 16 engages with the housing 10 at one end thereof. This arrangement can be readily seen in FIGS. 5 and 7 .

[0048] Alternatively, the discrete damping device 16 may be inserted into the push rod bore 14 .

[0049] The push rod 12 is operable to move between a first position and a second position. In the first position, the push rod 12 is retracted into the housing 10. A portion of the push rod 12 still protrudes through the housing 10. This position is shown in Figures 1 and 5. In the second position, the push rod extends out of the housing. This position is shown in Figure 7.

[0050] 5 and 7 also illustrate the working action of the damping device 16. As described above, the push rod 12 is configured to serve as a housing for the damping device 16. Two chambers are provided: a high pressure chamber 50 and a low pressure chamber 52. During the working stroke of the damper 16, the damping fluid is urged from the high pressure chamber 50 to the low pressure chamber 52.

[0051] Thus, in FIG. 5 , the damping fluid is substantially located within the high pressure chamber 50 , and during actuation of the damping device 16 , the damping fluid is transferred to the low pressure chamber 52 .

[0052] An advantage of using a push rod as the damper housing is that the overall length of the motion control device can be reduced.

[0053] A volume compensator 54 is provided at the end of the hole 14. This may be a compressible material. As can be seen from a comparison between Figures 5 and 7, the volume compensator has a reduced volume (i.e. it is compressed) in the first position compared to the second position. Due to the reverse damping function of the motion control device, the volume compensator 54 is located at the low pressure chamber 52 (i.e. the motion control device inhibits the opening of the door or drawer, but not the closing of these components).

[0054] The push rod 12 also includes an indexing mechanism 18 operable to maintain the push rod in the first position or the second position after a compression stroke or an extension stroke.

[0055] The indexing mechanism 18 includes a guide rail 20 and a latch 22. The operation will be described in more detail below.

[0056] The spring 24 is disposed on one side of the push rod 12 in the housing 10 .

[0057] The push rod 12 comprises a flange 26 with a through hole 28. A guide rod 30 is arranged in the housing 10. The spring 24 and the flange 26 are configured to be able to travel on the guide rod 30. The arrangement of the guide rod 30 ensures that the spring 24 remains on its operating axis. The spring 24 is a compression spring intended to push the flange 26 along the guide rod 30. Accordingly, this action is intended to push the push rod 12 to its second position.

[0058] By arranging the spring 24 to one side of the push rod 12, the length of the device can be reduced compared to a similar device where the push rod, damper and spring are all coaxial.

[0059] A smooth opening action is achieved by providing a damping device that engages the push rod 12 throughout its travel path. In addition, by providing controlled damping for the push rod 12 throughout its working stroke, the force acting on the latch 22 is reduced, which brings a longer working life to the device.

[0060] Figures 5 to 7 show the internal structure of the motion control device. By comparing Figures 5 and 7, it will be apparent that the damper has a working stroke that substantially corresponds to the distance traveled by the push rod 12 between the first position and the second position. Accordingly, the damping device 16 acts on the entire working stroke of the push rod 12.

[0061] The bore 14 in the push rod 12 extends over almost the entire length thereof. Accordingly, the working stroke of the piston of the damping device 16 (shown by the length X in FIG. 7 ) can extend through almost the entire length of the push rod 12. To achieve this effect, preferably, the length X is greater than or at least equal to the distance traveled by the push rod 12 between the first position and the second position - the length Y (shown with respect to both FIG. 5 and FIG. 7 ).

[0062] The spring 24 is typically a compression spring. The force applied by the spring 24 will decrease as the spring 24 moves from its most compressed state to its most extended state. Thus, when the push rod 12 moves from the first position to the second position, the force applied to the flange 26 will decrease. To ensure a smooth damping function, the damping device 16 may be configured to provide a damping function that decreases along its working stroke.

[0063] Now combine Figures 8 to 10A second embodiment is described. In this arrangement, the spring 24 is coaxial with the push rod 12. The push rod 12 comprises a hollow bore which receives or at least partially receives the spring 24. The spring 24 is intended to push the push rod 12 from the closed position to the open position.

[0064] The push rod 12 includes a first end that is engaged with a door or drawer of a furniture product and a second end that is always retained in the housing 10. The flange 32 is located at the second end of the push rod 12, such as at Figures 8 to 10 The flange can be further positioned along the push rod 12, but arranging the flange 32 at the second end of the push rod 12 allows the flange to run along the entire working stroke of the push rod.

[0065] Fig. 9 A plan view of the motion control device according to the second embodiment is shown with the push rod 12 in the closed position. Or, in other words, the arrangement of the motion control device when the drawer or door is closed.

[0066] Fig.10 The same device is shown with the push rod 12 in the open position, or the configuration of the motion control device when the drawer or door is open.

[0067] The damping device 16 is pivotally mounted within the housing about a pivot 34. In the closed position, the damping device 16 is disposed at an acute angle to the push rod 12. Typically, the damping device will be a piston and cylinder arrangement.

[0068] A cam surface 36 is provided in the housing 10 .

[0069] During the working stroke of the push rod 12, the flange 32 engages the damping device 16. When the push rod 12 travels from the closed position to the open position, the flange forces the damping device to rotate about the pivot 34. Thereby, the damping device 16 is urged against the cam surface 36. This action causes the damping device to be compressed, thereby causing a damping action.

[0070] The damping device 16 may be mounted within a sleeve 60. The sleeve 60 is pivotally mounted in the housing 10. At least one of the damper housing or the piston rod may slide relative to the sleeve 60, thereby allowing the damping device 16 to be compressed when it is urged against the cam surface 36.

[0071] In this embodiment, the spring 24 is coaxially located with the push rod 12, but the damping device 16 is located on one side of the push rod 12. By locating the damping device 16 outside the main axis of the push rod, the motion control device is shorter in length.

[0072] Thus, it is apparent that in the second embodiment, the damping device 16 is operable to rotate between a first position and a second position. In a preferred embodiment, the first position is angled relative to the longitudinal axis of the push rod 12. When the flange pushes the damper, the damping device 16 is pushed into a position generally longitudinally parallel to the push rod 12.

[0073] It will be appreciated that the further the flange 32 travels from the pivot 34, the greater the force exerted by the flange 32 on the damper 16. Thus, as the force exerted by the spring decreases as the spring stretches, the force exerted by the flange on the damper increases. The result is a smooth, substantially constant force exerted on the damper device during the working stroke of the spring 24.

[0074] An advantage of the arrangement of both the first and second embodiments is that the damper engages with the push rod in a manner that substantially extends throughout the entire travel path of the push rod. This results in the damper being operable to act on the push latch throughout the entire opening operation. It is known to arrange the damper outside the push rod axis, but the damper does not engage during the entire operating stroke of the push rod. Such an arrangement may cause a violent initial opening before the damper takes effect. Such an arrangement may cause stress on the indexing mechanism, which may ultimately jeopardize the operation of the push latch 22.

[0075] Both the first and second embodiments are suitable for being assembled to a mounting plate 38. Figures 3 and 4 show the mounting plate and the lower portion of the housing 10, respectively. It will be appreciated that the second embodiment will incorporate these features in exactly the same manner. The advantage of this arrangement is that it prevents damage to the device if the door or drawer is slammed shut. Specifically, the engagement of the housing 10 and the mounting plate is designed to allow the motion control device to be released from the mounting plate during a strong closing impact. The base plate includes an inclined nose 40 that is flexible in directions A and B, respectively, as shown in Figure 3. The lower portion 10b of the housing 10 includes an inclined nose 42 that cooperates with the inclined nose on the base plate. Therefore, if the motion control device is released from the base plate after a strong impact, it is easy to re-clamp the damper to the mounting plate.

[0076] Specifically, the housing is forced to disassemble from the base plate during excessive lateral force in a direction substantially perpendicular to the longitudinal axis of the push rod. This direction is shown in FIG. 3 by arrows (A, B).

[0077] The mounting plate 38 typically includes one or more screw holes to allow it to be fixed to the interior of a cabinet or drawer. A positioning flange 44 may be provided to help position the mounting plate in a furniture item.

[0078] The operation of the indexing mechanism will now be described. Such an arrangement is known from WO2019 / 064061, the contents of which are incorporated herein by reference.

[0079] The movement of the push rod 12 is controlled by an indexing mechanism 18 . Figures 11 to 15 An indexing mechanism 19 is shown, which includes a latch 22 and a guide rail 20. The latch 22 is a circular rod segment bent into a generally known Z-shaped configuration, with two ends extending perpendicularly in opposite directions to either side of its central portion. One of the ends 22a engages in a hole in the housing 10, serving as a fulcrum for the latch 22 to pivot. The other end 22b engages in the guide rail 20, mounted on the push rod 12 or forming part of the push rod 12. The latch 22 and its two ends 22a, 22b are also shown in Figures 5 and 7. The guide rail 20 is generally in the shape of an elongated ring with straight segments 20a and 20b extending between latch recesses 20c and 20d.

[0080] Fig.11 The indexing mechanism 18 of the device is shown in a loaded state and here the push rod 12 is always held in the innermost position of the housing 10 by retaining the end 19b of the latch 22 in the latch recess 20c. This is the normal state of the device when the drawer or door of the furniture item is closed.

[0081] To open a drawer or door, a small thrust is applied to it, thereby generating a force on the push rod 10 such as Fig.12 This causes the latch 22 to move along the guide rail 20 toward its straight section 20a. This releases the push rod 12 so that it moves out of the housing under the bias of the spring 24. This movement of the push rod 12 Fig.13 Indicated by arrow B.

[0082] The push rod 12 will continue to move out of the housing 10 until the latch 22 engages its end 19b with the latch recess 20d. Fig.14 The position shown in FIG. 1 is the fully extended state of the device. This is the state the device will be in when the drawer or door is open.

[0083] Closing the drawer or door will reset the device. Fig.15 2, wherein the closing movement of the drawer or door will exert a force indicated by arrow C on the push rod 12. This will cause the latch 22 to move along the guide rail 20 in such a way that the end 22b disengages from the latch recess 20d and reaches the straight section 20b. This movement will continue until the latch 22 engages its end 22b with the latch recess 20c, at which time the spring 24 is fully compressed and returns to the straight section 20b. Fig.11 The loaded state of the device is shown in FIG.

[0084] The device preferably incorporates a mechanism for adjusting the extent to which the push rod 12 protrudes beyond the housing 10. For example, the push rod 10 may be provided with a threaded end 46 to enable its overall length to be adjusted. This enables the device to be customized to fit the furniture item in use, thereby ensuring the correct closing and opening movement of its drawer or door. The threaded end 46 may be tethered via an internal anchor to ensure that it cannot be removed from the push rod 12. It will be appreciated that the threaded end 46 is not shown in FIG. 2 .

[0085] If the mounting plate 38 is not used, the housing 10 may include a flange 44 to help position the motion control device on an item of furniture. In this example, screw holes may be set on the additional side flanges.

[0086] By providing a motion control device according to the present invention, a push latch of small size, enabling controlled opening of a drawer / door and of robust design is provided.

[0087] It will be appreciated that the above embodiments are described by way of context only and that numerous modifications and variations are covered by the appended claims.

Claims

1. A motion control device, include: case; an elongated push rod mounted in the housing for reciprocating movement along a longitudinal axis between a first position and a second position, wherein the push rod extends out of the housing in both the first position and the second position, and wherein the second position is a more extended position relative to the first position; a spring including a spindle operable to provide a biasing force on the push rod; as well as a damping device comprising a spindle, wherein the damping device is directly or indirectly in substantially continuous engagement with the push rod through reciprocating motion of the push rod and is configured to provide a damping force on the push rod when the push rod moves from the first position to the second position, wherein The main axis of the spring and the main axis of the damping device are not coaxial; The main axis of the damping device is coaxial with the longitudinal axis of the push rod.

2. The motion control device of claim 1, comprising an indexing mechanism for controlling movement of the push rod relative to the housing, wherein the indexing mechanism is operable to maintain the push rod in the first position or the second position.

3. The motion control device according to claim 1, in, The push rod comprises a through hole along its longitudinal axis, so that the push rod comprises a housing of the damping device.

4. The motion control device according to claim 3, in, The damping device is a linear damper including a piston.

5. The motion control device according to claim 4, in, The working stroke of the piston is at least as long as the travel path of the push rod between the first position and the second position.

6. A motion control device according to any one of the preceding claims, in, The major axis of the spring is substantially parallel to the longitudinal axis of the push rod.

7. The motion control device according to claim 6, in, The push rod includes a flange, wherein the spring is retained between the flange and the housing.

8. The motion control device according to claim 7, in, The spring pushes the flange to move the push rod from the first position to the second position.

9. The motion control device according to claim 8, in, The damping device is configured to provide a decreasing damping force on the push rod as the push rod moves from the first position to the second position.

10. The motion control device of claim 1, comprising a base plate releasably engaged with the housing.

11. A motion control device, include: case; an elongated push rod mounted in the housing for reciprocating movement along a longitudinal axis between a first position and a second position, wherein the push rod extends out of the housing in both the first position and the second position, and wherein the second position is a more extended position relative to the first position; a spring including a spindle operable to provide a biasing force on the push rod; as well as a damping device comprising a spindle, wherein the damping device is directly or indirectly in substantially continuous engagement with the push rod through reciprocating motion of the push rod and is configured to provide a damping force on the push rod when the push rod moves from the first position to the second position, wherein The main axis of the spring and the main axis of the damping device are not coaxial; The spring is at least partially mounted within the push rod, the damping device is pivotably mounted to one side of the push rod in the housing, and movement of the push rod causes rotational movement of the damping device.

12. The motion control device according to claim 11, in, The push rod includes a flange operable to engage the damping device such that a spindle of the damping device is caused to rotate relative to a longitudinal axis of the push rod when the push rod moves from the first position to the second position.

13. The motion control device according to claim 12, in, When the pushrod is in the first position, the major axis of the damping device and the longitudinal axis of the pushrod define an acute angle, and when the pushrod is in the second position, the major axis of the damping device and the longitudinal axis of the pushrod are substantially parallel.

14. The motion control device according to any one of claims 11 to 13, in, The damping device is mounted in a sleeve, the sleeve is pivotally mounted in the housing, and at least one of a damper housing or a damper piston is slidably mounted in the sleeve.

15. The motion control device of claim 11, comprising a base plate releasably engaged with the housing.

16. The motion control device according to claim 15, in, The base plate and the housing include complementary noses that allow the housing to be releasably clamped into the base plate.

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