This invention relates to damper assemblies and in particular, though not exclusively, to damper assemblies for use in furniture.

For moving parts of furniture, such as doors for kitchen cupboards, it is desirable to provide damped resistance to the closing movement of the doors to prevent their slamming shut. Damper assemblies that are used for this purpose typically use damping devices of the piston and cylinder variety and are typically fitted to the cupboard carcase to act on the door in the vicinity of the hinge. With assemblies of this sort, it is desirable to have some means of adjustment, so that the damping action can be tailored to suit the door. In the prior art, adjustment mechanisms for damper assemblies often take the form of a screw-threaded device, as for example in US 2009/229077 or US 2009/119876. Because the screws in these mechanisms are positioned on the inner end of the assemblies, however, it can be awkward for a person to make a suitable adjustment. Also, the presence of the adjusting screw adds to the overall bulk of the assembly, to the detriment of the interior volume of the cupboard.

The present invention provides a damper assembly comprising a housing, a buffer mounted for reciprocal linear movement and extending out of the housing, the buffer providing a damped resistive force when being pushed back into the housing, spring biassing means urging the buffer towards its extended position and means for limiting the extent of protrusion of the buffer out of the housing.

By way of example, various embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 shows a first form of damper assembly according to the invention,

Figures 2a and 2b are views of the housing element of the damper assembly of Figure 1,

Figures 3 and 4 show respectively the damping device and adjusting collar of the damper assembly of Figure 1,

Figure 5 shows a second form of damper assembly according to the invention,

Figures 6a and 6b are views of the housing element of the damper assembly of Figure 5,

Figures 7 and 8 show respectively the damping device and adjusting collar of the damper assembly of Figure 5, Figure 9 shows a third form of damper assembly according to the invention,

Figures 10 and 11 show respectively the damping device and adjusting collar of the damper assembly of Figure 9,

Figure 12 shows a fourth form of damper assembly in position on a hinge, and Figure 13 shows a fifth form of damper assembly according to the invention.

The damper assembly 10 seen in Figure 1 comprises a housing 11 in which is mounted a damping device 12. The assembly 10 is mountable onto the carcase of a cupboard by suitable means 13 in order for the assembly to provide a damping resistance to the closing movement of the cupboard door. The mounting means 13 in this case is the subject of our application No. PCT/S12009/000058.

As seen in Figure 3, the damping device 12 is in the known form of a linear piston and cylinder type damper, with a piston rod 14 actuating a piston (not shown) within a cylinder 15 containing a viscous medium such as silicone. The cylinder 15 incorporates a spring (not shown) to return the piston rod 14 to its extended position. The damping device 12 has a longitudinal axis 19. As seen in Figure 1, the free end of the cylinder 15 protrudes out of the housing 11, where it is designed to be contacted by the cupboard door as it closes. For this purpose, a buffer pad 27 of rubber or the like is fitted to the end of the cylinder 15.

The damping device 12 is mounted within a chamber 16 in the housing 11. As seen in Figure 2b, the chamber 16 is bounded at least in part by a cylindrical wall section 17. The wall section 17 terminates mid-way along the housing 11 at an end face 18. As seen in Figure 2b, the end face 18 lies at an acute angle to the longitudinal axis 19 of the damping device 12. When the damping device 12 is in position in the housing 11, a lug 20 on the outside of the cylinder 15 engages the angled end face 18. The lug 20 will be urged into engagement with the angled end face 18 by the action of the return spring within the cylinder 15 acting through the piston rod 14 against a closed end section 11a of the housing 11. It will be understood from this arrangement that the rotational orientation of the damping device 12 relative to the housing 11 will determine the extent to which the free end of the cylinder 15 protrudes out of the housing, by virtue of the engagement of the lug 20 on the end face 18, and that the protrusion of the cylinder can be adjusted by rotating the damping device. Thus, the end face 18 effectively acts as a camming surface, with the lug 20 acting as a follower.

The end face 18 is ideally configured to provide a camming surface in the form of a regular helical track: this will produce a uniform amount of axial displacement of the damping device 12 relative to the housing 11 per degree of rotation of the damping device. The helical track is designed to have a relatively large pitch, that is to say, a small amount of rotation of the damping device will produce a relatively large amount of axial displacement of the damping device. The ratio of axial displacement to angular rotation might typically be in the order of 10 to 20 times greater than that obtained with a standard screw thread. Such a high gearing has the advantage of allowing adjustments to be effected more quickly than with a standard screw-thread adjuster. Also, with the movement of the damping device at adjustment being more easily seen, the adjustment process is easier to accomplish in practice.

A corollary of providing a relatively highly geared camming surface is that a control mechanism needs to be provided for holding the cam follower in position after adjustment. Here, the control mechanism takes the form of a collar 21. The collar 21 is rotatably mounted on the housing 11 and is positioned at the front end of the chamber 16, where it is retained by means of a snap fit. The collar 21 has a rib 22 on its outer surface. The rib 22 is designed to be located within an arcuate slot 23 in the housing 11 when the collar 21 is in position. This arrangement means that the range of possible rotational movement of the collar 21 is effectively constrained between two end limits.

On its inner bore, the collar 21 is splined with four equally spaced grooves 24. These are designed to match corresponding splines 28 on the protruding end of the cylinder 15. This arrangement means that the damping device 12 is fixed relative to the collar 21 in a rotational sense, but capable of linear axial movement relative to the collar. Thus, rotational movement of the collar 21 will cause axial displacement of the damping device 12 relative to the housing 11 by the cam and follower action of the lug 20 on the angled end face 18.

The outer surface of the collar 21 is contoured, here with a ribbed and grooved pattern 25. This is designed to engage with a series of serrations 26 on the housing 11 when the collar 21 is in position. The effect of this arrangement is to provide a ratchet-like mechanism to retain the collar 21, and hence also the damping device 15, in its chosen rotational position after adjustment.

When the damper assembly 10 is to be mounted to a cupboard, it is first fixed in position using the mounting mechanism 13. The position of the buffer pad 27 is then adjusted to suit the door. If the buffer pad 27 is adjusted to extend further out of the housing 11, this will mean that the door will encounter it sooner in its closing movement and hence the assembly will effectively apply a greater damping resistance. Adjusting the buffer pad 27 so that it extends less far out of the housing 11 will have the opposite effect. In this way, the damping action can be tailored to suit different doors.

It will be noted that the whole damper assembly 10 is constructed using just three components: the damping device, the housing and the collar. The assembly 10 thus provides a simple mechanism for allowing adjustment of its damping action in situ. Adjustment can be effected by rotating the collar 21 and/or the splined end of the cylinder 15. Because both the splined end of the cylinder 15 and the collar 21 are at the front end of the assembly 10 (i.e. facing out of the cupboard), there is ease of access for the adjustment process. Also, the arrangement means that the assembly 10 does not intrude any further into the cupboard interior than necessary.

The form of damper assembly 210 seen in Figure 5 is essentially the same as the assembly 10 of Figure 1 in terms of its basic functionality. It has a housing 211 in which is mounted a damping device 212 of the same linear piston and cylinder variety. The housing 211 is designed to be mountable onto the carcase of a cupboard (here using fasteners such as screws through mounting holes 250), with the free end of the cylinder 215 and its buffer pad 227 protruding out to engage the cupboard door and provide damped resistance to its closing movement.

The housing 211 has a cylindrical wall section 217 having an end face 218 that lies at an acute angle to the longitudinal axis 219 of the damping device 212. As in the previous assembly, the end face 218 is in the form of a helically extending track with a relatively large pitch and is designed to be engaged by a lug 220 on the cylinder 215 of the damping device 212, under the biassing action of a return spring (not shown) within the damping device which presses the piston rod 214 against a closed end section 211a of the housing 211. Again, the arrangement means that the rotational orientation of the damping device 212 relative to the housing 211 will determine the axial position of the free end of the cylinder 215 relative to the housing. The extent to which the free end of the cylinder 215 protrudes out of the housing 211 is adjusted by altering its rotational orientation, under the action of the lug 220 on the angled end face 218. Again, therefore, the angled face 218 acts effectively like a camming surface, with the lug 220 being a follower.

As in the previous embodiment, there is a control mechanism for holding the damping device 212 in position after adjustment. This takes the form of a collar 221. The free end of the cylinder 215 is splined, here with three equally spaced longitudinal ribs. The collar 221 has a matching spline arrangement 230 and fits over the cylinder 215. The collar 221 is rotatably mounted in a slot 250 in the housing 211 (seen in Figure 6a). The arrangement means that the protrusion of the free end of the cylinder 215 out of the housing 211 can be adjusted by turning the free end of the cylinder and/or by turning the collar 221, which for ease of grasping has an outwardly extending boss 222. The boss 222 is shaped so that it also functions to restrict the range of possible rotational movement of the collar 221, and hence also the linear displacement of the damping device 212, within defined end limits.

The collar 221 also features a series of serrations 225. These are arranged on an axial end face of the collar 221 and are designed to engage with a rib 226 on the housing 211 (see Figure 6a). The engagement of the serrations 225 with the rib 226 provides a ratchet-like connection between the collar 221 and the housing 211 which serves to ensure that the collar, and hence also the damping device 212 will remain in its chosen position after adjustment. The form of damper assembly 310 seen in Figure 9 is again similar to the previously described embodiments in that it comprises a housing 311 in which a piston and cylinder type damping device 312 is mounted. The housing 311 is mountable on the carcase of a cupboard in such a way that the free end of the cylinder 315 of the damping device 312 with its buffer pad 327 comes into contact with the cupboard door and provides damped resistance to its closing movement.

The position of the free end of the cylinder 315 is again adjustable relative to the housing 311 in order to enable the damping action of the assembly to be tailored to suit the door. The adjustment mechanism is again in the nature of a camming surface with a follower. The follower is again in the form of a lug 320 on the cylinder 315 of the damping device 312. The camming surface here is provided not on the housing 311, but on a collar 321, in the form of an angled end face 318 (see Figure 11). The collar 321 here thus not only acts as the driver for the adjustment mechanism, it also serves as the control mechanism for holding the damping device in position after adjustment.

The collar 321 is rotatably mounted in a slot 350 in the housing 311, with the lug 320 on the cylinder 315 engaging its angled end face 318. The lug 320 is pressed into engagement with the angled end face 318 by the action of the return spring within the damping device 312 biassing the piston rod 314 against a closed end section 311a of the housing 311. The arrangement means that the rotational orientation of the collar 321 relative to the housing 311 determines the axial position of the damping device 312 relative to the housing. Thus, the extent to which the free end of the cylinder 315 protrudes out of the housing 311 is adjusted by rotating the collar 321. To ensure that the cylinder 315 does not also rotate, this has a longitudinal rib 360 which keys into a suitable groove 361 in the housing 311. The collar 321 is provided with a pattern of serrations 325 extending around its circumference. A wing 326 on the housing 311 is designed to engage these serrations 321 and thus provide the collar 321 with a ratchet-like brake to ensure that it will remain in its chosen rotational position after adjustment. The collar 321 is shaped with an outwardly extending knob 322 for grasping, to facilitate the adjustment process.

The form of damper assembly 410 seen in Figure 12 is similar to the assembly 310 of Figures 9, 10 and 11, but is arranged to be mounted directly on a hinge assembly, rather than on a cupboard carcase. Thus, the assembly 410 has a housing 411 that is designed to fit over and attach to the part of the hinge assembly 500 that is mounted on the cupboard carcase C. The free end of the cylinder 415 is seen projecting forwardly, where it will come into contact with the cupboard door D as it closes. The amount of damping resistance that the assembly 410 will give to the door D will depend on how long the door is in contact with the buffer pad 427 and this is determined by the relative position of the free end of the cylinder 415. Using the knob 422, the collar 421 is easily rotated to adjust this position.

In the above embodiments, instead of being formed as a separate part, it would of course be possible to make the damper assembly as an integral part of the hinge assembly. Also, instead of contacting the door, it would be possible to arrange for the buffer pad to come into contact with a part of the hinge in order to provide damped resistance to the closing movement of the door.

The damper assemblies described above all have the camming surface/cam follower mechanism arranged with the camming surface on the housing or collar and the follower on the damping device. It will be appreciated that assemblies could equally well be designed with these components the other way round, i.e. the camming surface could be provided on the damping device or colla, with the follower on the housing. An example of such an alternative arrangement is seen in Figure 13. In this embodiment, the camming surface takes the form of a helical track 518 which extends around the outer surface of the cylinder 515 of the damping device 512. The helical track 518 is engaged by a lug 520 which is integrally formed in the housing 511. A spring (not shown) acting on the piston 514 of the damping device 512 ensures that the helical track 518 is held in engagement with the lug 520 on the housing 511. As in previous embodiments, a collar 521 is mounted between the damping device 512 and housing 511 to ensure that the buffer 514 that extends out of the housing remains in position after adjustment. The collar 521 also forms part of the adjustment mechanism.

The connection between the collar 521 and the buffer 514 is configured, e.g. using splines 528, so that the two parts will rotate together, but can move axially relative to one another. When the collar 521 is rotated, therefore, this will alter the rotational position of the helical trade 518 relative to the lug 520, which will in turn cause an axial displacement of the buffer 514. This is how the assembly is adjusted. A series of serrations 525 on an axial face of the collar 521 engage a corresponding series of serrations 526 on an end face of the housing to provide a ratchet-like mechanism for holding the collar in position rotationally.

It will be noted that in all the above described embodiments, the damper assembly consists of just three components: a damping device, a housing and a collar. This helps to minimise the cost of production of the assemblies.