GB2579424A - Buffer apparatus - Google Patents

Abstract

A buffer apparatus 200 for a heavy goods vehicle, such as a trailer, the apparatus comprising: a first housing 202; a second housing 204; at least one roller 206a,b rotatably attached to the second housing; and a damping element 208 disposed between the first and second housings. The second housing being slidably coupled to the first housing such that, when the at least one roller impacts an external object, the second housing slides relative to the first housing to thereby apply a compression force to the damping element. The coupling between the first and second housing may comprise at least one coupling element, each element comprising a sliding pin 232 and a longitudinal aperture or groove 310a,b. Two rollers may be provided, said rollers being disposed in line with the damping element. The damping element may allow the buffer to absorb a compressive force when the vehicle contacts an external structure, for example a loading dock, and the rollers may rotate to account for a vertical movement when the vehicle is loaded/unloaded

Description

BUFFER APPARATUS

The present invention relates to a buffer apparatus. In particular, but not exclusively, the present invention relates to a buffer apparatus for a heavy goods vehicle (HGV). The buffer apparatus, in use, is typically attached to the rear of the HGV for reducing damage when a HGV reverses up to an external object, for example a loading deck.

Background

Traditionally, Heavy Goods Vehicles (HGVs) are used to transport goods, for example from a supplier to a warehouse. Typically, a warehouse or other recipient location e.g. a supermarket, will have loading/unloading docks. These docks are designed to receive the rear end of the HGV so that goods may be easily transferred out of or into the HGV.

The rear of a HGV is often a blind spot to the driver. As such, when an HGV reverses into a loading dock the rear of the trailer may impact against the loading dock. Also, in some instances, it is desired for the rear of the trailer to abut against the loading dock so as to form a sealed abutment between the trailer and the loading dock. This impact or abutment can sometimes cause damage to either or both of the dock itself or the trailer. Therefore, it is common to include a buffer apparatus on the rear of an HGV trailer. A buffer apparatus extends outwardly from the back of a trailer to provide a contact surface for impacting the dock.

A buffer apparatus acts to reduce the possibility of damage to the loading dock or trailer by providing a surface intended to be the first area of impact of the rear of the trailer against an external object.

Fig. 1 shows an example of a trailer 100 which includes a buffer 110 according to the prior art. The buffer 110 is a longitudinal member, commonly formed of a hardwearing material such as steel. The buffer 110 is disposed on the rear surface of the trailer 100. That is, the buffer 110 protrudes away from the rear of the trailer 100, such that when the trailer is reversed into a loading dock the buffer 110 contacts the dock before the trailer 100. The buffer 100 extends laterally across substantially the whole width of the rear surface of the trailer.

Other examples of buffer arrangements are hard rubber protrusions. These protrusions can be mounted on the rear of an HGV, such that when an HGV reverses into a loading dock the protrusion contacts the dock before the trailer. The protrusions are fixably mounted to the HGV.

Once a trailer is received into the dock, with the buffer abutting against the dock, goods can be loaded into or out of the trailer. Often goods are transported in large quantities by a pallet truck for example. Goods passing over the rear of the trailer can cause the rear of the trailer to dip. This adds strain to the buffer attached to the rear of the trailer. Repeated strain on the buffer in this way reduces the lifetime of the buffer. Moreover, the movement of goods into or out of the trailer can cause the buffer to rub against the stationary sides of the dock, thus causing wear to both the buffer and dock. Increased strain and wear on the buffer results in a buffer having to be regularly replaced. This can incur significant time and costs.

A roller arrangement can be included as the impact portion of the buffer assembly. A roller acts so that the buffer assembly rolls against the dock to allow for dipping of the trailer. EP1369307A and EP2353943A disclose buffers including a roller.

It would be useful to provide a buffer arrangement with increased longevity.

According to a first aspect of the present invention there is provided a buffer apparatus for a heavy goods vehicle, the apparatus comprising: a first housing; a second housing; at least one roller rotatably attached to the second housing; and a damping element disposed between the first and second housing, wherein the second housing is slidably coupled to the first housing such that, when the at least one roller impacts an external object, the second housing slides relative to the first housing to thereby apply a compression force to the damping element.

Suitably, the second housing is configured to linearly slide relative to the first housing in a direction substantially perpendicular to an axis of rotation of the roller.

Suitably, the roller is disposed in-line with the damping element.

Suitably, at least one of the first housing or second housing comprises an abutment surface, the abutment surface configured to abut the damping element as the second housing slides towards the first housing and to substantially evenly distribute the compression force across the damping element.

Suitably, the abutment surface is substantially planar and parallel to a corresponding abutment surface of the damping element to thereby substantially evenly distribute the compression force across the damping element.

Suitably, a rear portion of the first housing forms the abutment surface.

Suitably, the damping element is coupled to one of the first housing or the second housing.

Suitably, the buffer apparatus comprises at least two rollers rotatably attached to the second housing.

Suitably, the second housing is slidably coupled to the first housing via at least one coupling element, wherein each coupling element comprises a slide pin and a longitudinal aperture or groove shaped to receive a portion of the slide pin, wherein the slide pin is configured to slide along the longitudinal aperture or groove such that the second housing slides relative to the first housing.

Suitably, the slide pin is fixedly coupled to one of the first housing or the second housing, and the longitudinal groove is disposed in the other of the first housing and the second housing.

Suitably, the second housing is slidably coupled to the first housing via at least two coupling elements, wherein a first of the at least two coupling elements comprises a longitudinal aperture or groove disposed on a first side portion of the first housing and a second of the at least two coupling elements comprises a longitudinal aperture or groove disposed on a further side portion of the first housing.

Suitably, the slide pins slidably couple the first and second housing.

Suitably, the longitudinal aperture or groove is disposed substantially perpendicular to an abutment surface of the damping element.

Suitably, the first housing is configured for coupling to the rear of a trailer.

According to a second aspect of the present invention, there is provided a trailer for a heavy goods vehicle, the trailer comprising at least one buffer apparatus mounted to the trailer.

Aptly, the buffer apparatus may be mounted to a rear end of the trailer.

For the avoidance of doubt the trailer according to the second aspect may include a buffer apparatus according to any of the example buffer apparatus described herein.

Certain embodiments of the invention provide the advantage that the lifetime of a buffer is increased.

Certain embodiments of the invention provide the advantage that a lighter buffer apparatus can be provided.

Certain embodiments of the invention provide the advantage that a buffer arrangement capable of allowing for vertical movement of a trailer against a stationary object is provided.

Brief description of the drawings

Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which: Fig. 1 illustrates an example of a buffer of the prior art; Fig. 2 illustrates a plan view of an example buffer apparatus; Fig. 3a illustrates a plan view of a further example buffer apparatus; Fig. 3b illustrates a perspective view the buffer of Fig. 3a; Fig. 4 illustrates a side view of the buffer apparatus of Fig. 3a and Fig. 3b; Fig. 5a illustrates an example of a slide pin arrangement; Fig. 5b illustrates another slide pin arrangement; Fig. 6 illustrates a side view of a portion of a trailer including a buffer apparatus; Fig. 7 illustrates a plan view of the trailer of Fig. 6; Fig. 8 illustrates a rear view of a trailer including a buffer apparatus; and Fig. 9 illustrates a perspective view of a portion of the trailer of Fig. 8.

In the drawings like reference numerals refer to like parts.

Detailed Description

Throughout the description reference is made to an "external object". This term is intended to encompass any object that a buffer assembly may abut against, including but not limited to a wall, a loading dock, a trailer, or a vehicle for example.

Fig. 2 illustrates an example arrangement of a buffer apparatus 200 for an HGV. In this example the apparatus includes a first housing 202, a second housing 204, at least one roller 206 and a damping element 208. The roller 206 is rotatably attached to the second housing 204 and the damping element is disposed between the first housing 202 and the second housing 204.

The second housing 204 is slidably coupled to the first housing 202 such that, when the roller 206 impacts an external object (for example, a loading dock), the second housing 204 slides relative to the first housing 202 to the thereby apply a compression force to the damping element 208.

At least one of the first housing 202 and the second housing 204 may include an abutment surface. In this example, the first housing includes an abutment surface 220. The abutment surface 220 is configured so as to abut the damping element 208 as the second housing 204 slides towards the first housing 202. The abutment surface 220 is aptly configured to substantially evenly distribute the compression force across the damping element 208.

For example, the abutment surface 220 may be substantially planar and parallel to a corresponding abutment surface of the damping element 208. In this way, the compression force may be substantially evenly distributed across the damping element 208.

The first housing is aptly configured for coupling to the rear of a trailer. For example, the first housing 202 may include an aperture on a rear surface thereof through which a bolt may extend. In other examples, the first housing may be welded to the rear of a trailer.

In this example, the first housing 202 is formed of three portions including a first side portion 212, a further side portion 214, and a central portion 216. The first side portion 212 is positioned opposite and spaced apart from the further side portion 214. The central portion 216 couples the first side portion 212 and further side portion 214. The first housing 202 forms a substantially U-shaped housing.

In this example, the second housing 204 is formed of three portions including a first side portion 222, a further side portion 224, and a central portion 226. The first side portion 222 is positioned opposite and spaced apart from the further side portion 224. The central portion 226 couples the first side portion 222 and further side portion 224. The second housing 204 forms a substantially U-shaped housing. The roller 206 is rotatably attached to the second housing 204 between the first side portion 222 and the second side portion 224 such that the axis of rotation of the roller is parallel to the central portion of the second housing 204.

Thus the width of the second housing 204 substantially corresponds to the length of the roller 206.

The second housing 204 is shaped similarly to the first housing 202 such that the second housing 204 may be substantially enclosed by the first housing 202.

The buffer apparatus is formed with the roller 206 rotatably attached to the second housing 204. The roller 206 may be attached to the second housing 204 by any standard means. For example, a longitudinal rod may be inserted through the roller such that the roller 206 can rotate freely about the longitudinal rod. In this way the roller 206 may rotate about a single central axis A. The longitudinal rod may be fixed with respect to the second housing 204 between the first side portion 222 and further side portion 224. That is, the longitudinal rod may extend from the first side portion 222 to the further side portion 224 and through the roller 206. Thus, the roller 206 may then rotate about the longitudinal rod.

The roller 206 may protrude from the second housing 204. That is, at least a portion of the curved surface of the roller 206 is exposed. Thus, when the buffer apparatus 200 impacts on an external object located at the roller side of the apparatus, the roller is the only portion of the buffer apparatus 200 that comes into contact with the external object.

The second housing 204 is slidably coupled to the first housing 202. That is, the second housing 204 is configured slide relative to the first housing 202. Aptly, the second housing 204 is configured to linearly slide relative to the first housing 202 in a direction substantially perpendicular to an axis of rotation A of the roller 206.

The second housing 204 may be slidably coupled to the first housing 202 via at least one coupling element. In this example, the coupling element includes a slide pin 232 and a longitudinal aperture or groove shaped to receive a portion of the slide pin. The slide pin is configured to slide along the longitudinal aperture or groove such that the second housing 204 slides relative to the first housing 202.

The slide pin 232 is aptly fixedly coupled to one of the first housing 202 or the second housing 204. The longitudinal groove is disposed in the other of the first housing or the second housing (i.e. the housing that is not fixedly coupled to the slide pin).

In this example, the apparatus includes two coupling elements. The first portion 212 of the first housing 202 is connected to the first portion 222 of the second housing 204 via a first slide pin 232a. The further portion 214 of the first housing 202 is connected to the further portion 224 of the second housing 204 via a further slide pin 232b. Corresponding longitudinal grooves or apertures (not shown) are disposed in the first portion 212 and the second portion 214 of the first housing 202.

In use, when the roller 206 abuts against an external object, the first and further slide pins 232a-b slide along their respective longitudinal grooves or aperture in the first housing 202, as will be discussed in more detail below with reference to Fig. 3b.

The damping element 208 is disposed between the first housing 202 and the second housing 204. In this example, the damping element 208 is located in a space formed between the central portion 226 of the second housing 204 and the central portion 216 of the first housing 202. The damping element 208 may be positioned substantially centrally in the longitudinal direction of the buffer apparatus. In other words, the midpoint of the damping element 208 is located in-line with the midpoint of the central portion 226 of the second housing 204.

The damping element may be coupled to either of the first housing 202 or the second housing 204. In this example, the damping element 208 is coupled to the second housing 204. The damping element 208 is fixed to the central portion 226 of the second housing 204. The damping element may be fixed by any suitable means, for example a bolt 234. The damping element 208 is positioned opposite and spaced apart from the roller 206. Aptly, the damping element 208 is disposed in-line with the roller 206.

In this example, the damping element 208 includes a first face 240 and a second face 230. The first and second faces are spaced apart and opposing one another. Aptly, each of the first face 240 and the second face 230 are substantially planar. The first face 240 of the damping element 208 abuts against the central portion 226 of the second housing 204.

The second face 230 of the damping element 208 opposes the first face 240. As such, in this example with the damping element coupled to the second housing 204, the second face 230 faces the central portion 216 of the first housing 202.

A rear portion of the first housing 202 may form the abutment surface 220. In this example, the central portion 216 of the first housing 202 includes the abutment surface 220. The abutment surface 220 is positioned in the interior of the buffer apparatus. In this way, the second face 230 of the damping element 208 faces the abutment surface 220. The second face 230 of the damping element 208 forms a further abutment surface 230.

In this example, the damping element 208 may be sized to cover up to 80% of the surface area of central portion 226 of the second housing 204. Aptly the damping element 208 may be from about 80 mm in diameter to about 120 mm in diameter, or more aptly about 108 mm in diameter. The damping element may have a thickness from 80 mm to 100 mm or more aptly 90 mm.

The abutment surface 220 of the first housing 202 is configured such that, as the second housing 204 slides towards the first housing 202 the damping element 208 abuts the abutment surface 220. The abutment surface 220 of the first housing 202 is aptly substantially planar. Aptly, the abutment surface 220 spans the width of the first housing to thereby provide a relatively large surface area over which to distribute any compression force. In this example, the abutment surface 220 is planar and parallel to the abutment surface 230 of the damping element 208, such that, as the second housing 204 slides towards the first housing 202, the damping element 208 abuts the abutment surface 220 evenly. Thus, the compression force across the damping element is distributed substantially evenly.

In this example, the damping element 208 is disposed in-line with (i.e. behind) the roller 206.

The damping element 208 is configured to absorb at least some of the impact force when the roller 206 impacts an external object. The roller 206 is positioned spaced apart from the damping element 208, such that the axis of rotation A of the roller 208 is parallel to the abutment surface 230 of the damping element 208. Specifically, the buffer apparatus is arranged such that, the first housing 202, the damping element 208, the second housing 204 and the roller 206 are assembled in an in-line configuration. Thus, an impact force may be evenly distributed across the damping element 208.

The even distribution of the impact force on the damping element helps to reduce uneven wear of the constituent parts of the buffer assembly.

The first housing 202 and second housing 204 may be formed of the same material or of different materials. For example, the first and second housing may be formed of steel.

In this example the roller 206 is formed from a hard wearing material for example steel, or hard rubber.

The damping element 208 (damper) may be formed from any suitable material capable of absorbing impact. The damping element 208 is aptly formed of a material with elastic properties, such that the damping element is able to withstand an impact force and return to its original shape. The damping element may be elastically deformable. In this example the damping element is formed of a hard rubber.

Fig. 3a, Fig. 3b and Fig. 4 illustrate an example of the buffer apparatus 200 as described above, including two rollers. The arrangement of the first housing 202 and second housing 204 is as described above and as such, shall not be described again for brevity.

In this example, the buffer apparatus 200 further includes a cover 360. The cover 360 is coupled to the first housing 202 and covers the central portion 226 of the second housing 204. That is, the cover is located over the rear of the second housing 204. In this example, the cover is coupled to the first side portion 212 and further side portion 214 of the first housing 202, e.g. via welding. The cover may alternatively be formed integrally with the first housing 202. The cover 360 may provide increased rigidity to the first housing 202 in the region where the first housing 202 is slidably coupled to the second housing 204.

In this example, the apparatus includes a first roller 206a and further roller 206b. The first roller 206a is stacked above the further roller 206b, such that the axis of rotation of the first roller 206a is parallel to and lies in the same plane as the further roller 206b. The axis of rotation of each of the first roller 206a and further roller 206b are spaced apart such that each of the rollers may freely rotate. The plane of the axis of rotation of the first and further rollers is parallel to the abutment surfaces of the first housing 202 and the damping element 208. Each of the first roller 206a and further roller 206b may be rotatably attached to the second housing 204 in any suitable manner such as that described above with reference to Fig. 2.

The damping element 208 is positioned centrally in respect of the first roller 206a and the further roller 206b. That is, the damping element is positioned such that the centre of the damping element 208 is positioned to be in-line with a point midway between the first 206a and further roller 206b.

Fig. 3b and Fig. 4 illustrates the coupling element slidably coupling the first housing 202 to the second housing 204. The first housing 202 includes a longitudinal aperture 310 on each of the first side portion 212 and further side portion 214. In this example, the first housing 202 includes two longitudinal apertures on each of the first side portion 212 and further side portion 214. In other examples, one or more longitudinal apertures may be included on each side portion of the first housing, for example, one, three or four longitudinal apertures. In this example, two longitudinal apertures on each side of the first housing can help to provide smooth sliding of the second housing relative to the first housing. Each longitudinal aperture 310 is shaped to slidably receive a portion of a respective slide pin 232. For example, the longitudinal aperture 310 may be stadium shaped.

The longitudinal aperture 310 determines the extent and direction of the movement of the second housing 204 relative to the first housing 202. In this example, the longitudinal aperture 310 extends in a direction substantially perpendicular to both the central portion 216 (abutment surface) of the first housing 202 and the axis of rotation of the rollers. The longitudinal aperture is also substantially perpendicular to the abutment surface of the damping element. Thus, the sliding motion of second housing 204 may be limited to a single linear direction.

The length of the longitudinal aperture may be selected according to the desired movement of the first housing relative to the second housing. The length of the aperture may also be selected according to the elasticity of the damping element. In this example the length of the longitudinal aperture 310 is 75 mm, and the width of the longitudinal aperture is 30 mm. In other examples, the length of the longitudinal aperture may be from 50 mm to 100 mm and the width of the longitudinal aperture may be from 20 mm to 40 mm depending on the diameter of the slide pin.

A slide pin 232 couples the second housing 204 to the first housing 202. In this example, the slide pin 232 is fixedly coupled to the second housing 204. A portion of the slide pin 232 extends through the aperture 310 in the first housing such that the second housing 204 is slidably coupled to the first housing 202. The slide pins are described in detail below with reference to Fig. 5 and as such will not be described here for brevity.

Fig. 5a illustrates an example of a slide pin arrangement of the buffer apparatus. For clarity, the roller and the damping element are omitted from the figure. In this example, a slide pin 510 extends from a first side portion 512 of the first housing 502, through the first side portion 522 and further side portion 524 of the second housing 504 and through to the further side portion 514 of the first housing 502. That is, the slide pin 510 passes through the first and further side portions of the first and second housings.

The slide pin 510 may be fixedly attached with respect to one of the first and second housings and may be slidably received within a longitudinal aperture or groove in the other of the first and second housings. For example, similarly to the example shown in Figs. 3 and 4, the slide pin may be fixedly attached to the second housing 204, for example via an aperture in the each of the first side portion 522 and further side portion 524 of the second housing 504. The aperture may be sized to correspond to the shaft of the slide pin 510 so as to prevent movement of the slide pin 510 with respect to the second housing 504.

Additionally or alternatively, the slide pin may be fixed to the second housing 504, for example by welding. In other examples, the slide pin 510 may be formed integrally with the second housing 504.

Similarly to the example shown in Figs. 3 and 4, the first housing 502 may include at least one longitudinal aperture in each of the first side portion 512 and further side portion 514. Each of the longitudinal apertures may have a width corresponding to the diameter of the shaft of the slide pin so as to allow for substantially linear movement of the slide pin 510 along the length of the aperture.

The slide pin 510 may extend parallel to the central portion 526 of the second housing and the axis of rotation of the roller. Upon application of an impact force to the second housing 504 via the roller element the second housing 504 will slide relative to the first housing 502 in a controlled manner.

In this example, the slide pin 510 has a first end stop 520a and a second end stop 520b located at either end of the slide pin 510 protruding from the first housing. The end stops 520 are configured to retain the slide pin 510 in position in the longitudinal aperture. In this example, the end stops are substantially disk shaped, having a larger diameter than the width of the longitudinal aperture, to thereby prevent passage of the ends of the slide pin 510 out of the aperture.

The slide pin may be made from any suitable material, for example steel or stainless steel.

Fig. 5b illustrates an alternative example of a slide pin arrangement of a buffer apparatus 500. In this example a first slide pin 570 extends through the first side portion 512 of the first housing 502 and the first side portion 522 of the second housing 504. A second slide pin 560 extends through the further side portion 514 of the first housing 502 and the further side portion 524 of the second housing 504.

The first slide pin 570 may include a first end stop 530a and a second end stop 530b. Similarly, the second slide pin 560 may also include a first end stop 540a and a second end stop 540b. The end stops may be similar to the end stops described above in relation to Fig. 5a to help retain the slide pin in position.

Each of the slide pins may be fixedly coupled to the second housing 504 and slidably coupled to the first housing 502 similarly to that described above in relation to Fig. 5a. Alternatively, each of the slide pins may be fixedly coupled to the first housing 504 (similarly to the fixed coupling described above) and may be slidably coupled to the second housing 504 (similarly to the slidable coupling described above).

Fig. 6 to Fig. 9 depict various views of the rear portion 650 of a trailer of a HGV which includes buffer apparatus. In the figures, the wheels of the trailer are omitted for clarity. In this example, a first buffer apparatus 600a and a further buffer apparatus 600b are shown affixed to a rear portion of a trailer. It will be understood that a trailer may include any appropriate number of buffer apparatus.

As shown in Fig. 6 and Fig. 7 the first buffer apparatus 600a is affixed to the lower rear of the trailer 650. For example, the first buffer apparatus 600a can be attached to the trailer chassis or other structural element. In this example, the first buffer apparatus 600a is attached securely to the trailer chassis. The first buffer apparatus 600a may be attached via any conventional means. For example, the buffer apparatus may be attached to the trailer via at least one bolt extending through the first housing and coupling with a structural element of the trailer chassis. In other examples, the first housing may be welded to a portion of the trailer, for example the trailer chassis.

In this example, the central portion of the first housing of the first buffer apparatus 600a is affixed to the trailer. As such, that the damping element is closer to the rear of the trailer than the roller 606. Thus, the roller 606 forms the first contact surface at the rear of the trailer. As such, in use, when the buffer apparatus 600 impacts an external object the roller 606 is the contact surface.

The first buffer apparatus 600a may be located in a lower corner of the rear portion 650 of the trailer. The first buffer apparatus 600a is positioned on the rear of the trailer so as to come into contact with an external object before the rear wall 620 of the trailer during a reversing manoeuvre of the HGV. Aptly the buffer apparatus 600 is connected to the lower part or the rear portion 650 of the trailer.

The buffer apparatus 600 is orientated on the trailer so that the axis of rotation of the roller 606 is perpendicular to the direction of the dipping motion. For example, if the dipping of the trailer 600 would occur in a vertical (up and down motion) then the buffer apparatus 600 may be coupled to the trailer in an orientation such that the axis of rotation of the roller 606 is horizontal. That is, the axis of rotation of the roller 606 is substantially horizontal to the ground when in use.

The roller 606 of the first buffer apparatus 600a extends beyond the rear wall 620 of the trailer. In this way, the roller 606 of the buffer is the rearmost surface of the HGV. Therefore, the first buffer apparatus 600a acts to cushion the force of impact onto the loading dock. In this example the first buffer apparatus 600a extends up to 300 mm beyond the rear of the trailer. Thus, the trailer can still be positioned relatively closely against a loading dock to allow for easy loading and unloading of goods.

As demonstrated in Fig. 7, 8 and 9 the rear portion 650 of the trailer may have more than one buffer apparatus attached. In this example a first buffer apparatus 600a is affixed to a first side 660 of the trailer chassis at the rear of the trailer and a further buffer apparatus 600b is affixed to the opposite side 670 of the trailer chassis at the rear of the trailer. The further buffer apparatus 600b is substantially identical to the first buffer apparatus 600a, and as such will not be described again for brevity.

In this example the first buffer apparatus 600a is positioned on the HGV symmetrically to the further buffer apparatus 600b. By including a plurality of buffer apparatus on the rear wall of a HGV an impact force is more evenly distributed between the first 600a and further 600b buffer apparatus.

In use, when a buffer apparatus as described above contacts an external structure an impact force is generated. The impact force is a compressive force which is applied to the roller of the buffer apparatus. The roller then transfers the compressive force to the second housing, which then slides relative to the first housing. This slide motion occurs as the slide pins move in the longitudinal apertures. The slide pins are fixed to, or formed integrally with the first or second housing and the longitudinal apertures are formed in the other of the first or second housing. The central portion of the second housing moves the damping element until the damping element abuts the abutment surface on the first housing. The second housing then applies a compression force, compressing the damping element against the abutment surface of the first housing. The damping element may then elastically deform to effectively absorb the compression force. In this way, the impact force transferred to the trailer via the buffer apparatus is significantly reduced.

Once the trailer is in position in the loading dock, the buffer apparatus may remain in a compressed state (e.g. with the damping element compressed). As goods are loaded and unloaded from the trailer, the trailer may experience vertical "dipping" movement relative to the loading dock. In this event, the rollers rotate to account for the vertical movement, whilst the second housing may slide relative to the first housing to account for any minor movements towards or away from the dock.

In this way, damage to both the trailer and/or the dock can be mitigated or significantly reduced.

Various modifications to the detailed designs as described above are possible. For example, the first housing may be positioned such that the second housing partially encloses the first housing. In other words, the first housing may be positioned inside of the second housing.

In other examples a cover may be included to substantially enclose the first and second housing. The cover may be used to protect the first and second housing, i.e. preventing dirt obstructing the sliding elements.

Throughout the description the damping element has been described as coupled to the second housing, however it should be understood that the damping element may alternatively be coupled to the first housing. In this example, the second housing includes an abutment surface against which the damping element abuts as the first and second housings slide relative to each other. Alternatively, the damping element may be coupled to both the first and second housing in any manner that allows compression of the damping element between the two housings (e.g. via a rod extending through the damping element and the central portion of each housing).

Although in the examples described above, the longitudinal aperture is provided in the first housing, in alternative examples the longitudinal aperture may be provided in the second housing. In some examples, a longitudinal groove (or recess) may be provided instead of an aperture, which extends only partially through the first or second housing. The longitudinal groove may be configured to slidably receive an end portion of the slide pin.

The damping element may alternatively be formed of a plurality of smaller damping elements. The plurality of damping elements may be substantially evenly distributed such that an impact force is distributed evenly across them.

Although the rollers have been described as being attached to the second housing via a longitudinal rod it will be understood that any standard means may be used. For example, the rollers may have a protruding flange at each end. Said flange may extend into an aperture in the second housing such that the roller can freely rotate.

Although the trailer is shown above with the buffer apparatus attached to the rear of the trailer, in other examples the trailer may include a buffer apparatus attached at varying positions around the perimeter of the trailer.

With the above-described arrangements a buffer apparatus can be provided with a second housing slidably coupled to the first housing such that when the at least one roller impacts an external object, the second housing slides relative to the first housing to thereby apply a compression force to the damping element.

By arranging the damping element behind and in line with the roller of the buffer assembly any movement is limited to two planes. For example, the buffer may allow for movement up and down vertically via the rolling element and forwards and backwards, via the slidable attachment of the first and second housing.

Limiting the planes of movement of the buffer apparatus provide a stable buffer apparatus capable of allowing for the dipping of a trailer due to loading and unloading of heavy goods and allows for soft reversing into a loading bay. The limitation of the planes of movement also provides the advantage that variations in the shape of the external object will not alter the damping capabilities of the buffer apparatus. In addition, the impact force is evenly distributed throughout the buffer apparatus, thus reducing risk of damage.

The above-described arrangement further provides the advantage that a smaller, lighter and more cost efficient buffer apparatus may be provided compared with some known buffer 30 apparatus.

The above-described arrangement provides the advantage that the buffer apparatus may be easily replaced or retrofitted to a trailer.

It will be clear to a person skilled in the art that features described in relation to any of the embodiments described above can be applicable interchangeably between the different embodiments. The embodiments described above are examples to illustrate various features of the invention.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of them mean "including but not limited to", and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims (15)

1. CLAIMSA buffer apparatus for a heavy goods vehicle, the apparatus comprising: a first housing; a second housing; at least one roller rotatably attached to the second housing; and a damping element disposed between the first and second housing, wherein the second housing is slidably coupled to the first housing such that, when the at least one roller impacts an external object, the second housing slides relative to the first housing to thereby apply a compression force to the damping element.
2. 2. A buffer apparatus as claimed in claim 1 wherein the second housing is configured to linearly slide relative to the first housing in a direction substantially perpendicular to an axis of rotation of the roller.
3. A buffer apparatus as claimed in claim 1 or 2 wherein the roller is disposed in-line with the damping element.
4. 4. A buffer apparatus as claimed in any preceding claim, wherein at least one of the first housing or second housing comprises an abutment surface, the abutment surface configured to abut the damping element as the second housing slides towards the first housing and to substantially evenly distribute the compression force across the damping element.
5. 5. A buffer apparatus as claimed in claim 5, wherein the abutment surface is substantially planar and parallel to a corresponding abutment surface of the damping element to thereby substantially evenly distribute the compression force across the damping element.
6. A buffer apparatus as claimed in any of claims 3 to 5, wherein a rear portion of the first housing forms the abutment surface.
7. 7. A buffer apparatus as claimed in any preceding claim, wherein the damping element is coupled to one of the first housing or the second housing.
8. 8. A buffer apparatus as claimed in any preceding claim, wherein the buffer apparatus comprises at least two rollers rotatably attached to the second housing.
9. 9. A buffer apparatus as claimed in any preceding claim, wherein the second housing is slidably coupled to the first housing via at least one coupling element, wherein each coupling element comprises a slide pin and a longitudinal aperture or groove shaped to receive a portion of the slide pin, wherein the slide pin is configured to slide along the longitudinal aperture or groove such that the second housing slides relative to the first housing.
10. 10. A buffer apparatus as claimed in claim 9, wherein the slide pin is fixedly coupled to one of the first housing or the second housing, and the longitudinal groove is disposed in the other of the first housing and the second housing.
11. 11. A buffer apparatus as claimed in claim 9 or claim 10, wherein the second housing is slidably coupled to the first housing via at least two coupling elements, wherein a first of the at least two coupling elements comprises a longitudinal aperture or groove disposed on a first side portion of the first housing and a second of the at least two coupling elements comprises a longitudinal aperture or groove disposed on a further side portion of the first housing.
12. 12. A buffer apparatus as claimed in any of claims 9 to 11, wherein the slide pins slidably couple the first and second housing.
13. 13. A buffer apparatus as claimed in any preceding claim, wherein the longitudinal aperture or groove is disposed substantially perpendicular to an abutment surface of the damping element.
14. 14. A buffer apparatus as claimed in any preceding claim, wherein the first housing is configured for coupling to the rear of a trailer.
15. 15. A trailer for a heavy goods vehicle, the trailer comprising at least one buffer apparatus as claimed in any preceding claim mounted to said trailer.