Elevator buffer

Abstract

The utility model discloses an elevator buffer, which comprises a base component, an elastic component, a plurality of elastic components and a plurality of elastic components, the base component limits a base concave part which extends upwards in use, and the base concave part is used for accommodating a part of a compressible energy absorber; a cap positioned, in use, over the base member, the cap defining one or more reaction surfaces for an elastically deformable member and a further downwardly extending cap recess for receiving a portion of a compressible energy absorber; a compressible energy absorber, the compressible energy absorber having respective sections received in the base recess and the cap recess; at least one wall extending between the base recess and the cap recess, the at least one wall being formed of or comprising a plastic material and defining a closed reservoir for fluid extending between the base member and the cap, an aperture extending through the cap.

Description

Technical Field

[0001] The utility model relates to an elevator buffer. Background Art

[0002] Elevator buffers absorb and dissipate energy when they are compressed longitudinally, and are typically mounted at the bottom of an elevator shaft or shaft, or at the bottom of an inclined track. Such a bottom location is at a distance (such as a few tens of centimeters or perhaps 1 to 2 meters) below the lowest expected range of travel of the associated elevator car with which the elevator buffer is configured for use. When the elevator car undershoots the lowest expected range of travel (as may occur due to, for example, component wear or lack of adjustment), it contacts and compresses the buffer longitudinally from above. The action of the buffer in compression then dissipates the kinetic energy in the elevator car. The purpose of this is to stop the elevator car smoothly and gradually, without shaking the occupants of the elevator car or any cargo being carried.

[0003] Elevator buffers as described have been manufactured in large quantities over the years. This is partly due to the boom in the construction of multi-story buildings and the prevalence of other moving elevator cars in recent decades. Utility Model Content

[0004] According to the utility model, in a broad aspect, there is provided an elevator buffer, comprising: a base member, the base member defining a base recess extending upwardly in use, the base recess being used to receive a portion of a compressible energy absorber; a cap, the cap being located above the base member in use, the cap defining one or more reaction surfaces for an elastically deformable member and a further downwardly extending cap recess for receiving a portion of the compressible energy absorber; the compressible energy absorber having respective sections received in the base recess and the cap recess; at least one wall, The at least one wall extends between the base recess and the cap recess, the at least one wall being formed of or comprising a plastics material and defining a closed reservoir for a fluid extending between the base member and the cap member, an aperture extending through the cap, the compressible energy absorber comprising a rod extending from the compressible energy absorber through the aperture, the rod comprising or having a reaction member fixed to the rod, the reaction member being spaced apart from the or each reaction surface in use; and the elevator buffer comprising a compressible, resiliently deformable member extending between the reaction member and the or each reaction surface.

[0005] There are many advantages to using plastics material to form the walls of the fluid reservoir defining the buffer. Chief among these advantages is that the weight of the buffer is significantly less than that of a buffer of the same size and load rating where all parts of the buffer (including the housing defining the reservoir) are made of steel.

[0006] The buffer is lighter than prior art products and cheaper to transport than steel buffers. It is also easier to handle and install.

[0007] Additionally, the use of plastic materials helps reduce manufacturing costs while maintaining effective buffer operation. This is especially important when compared to using other materials that are subject to price fluctuations in the international market.

[0008] Furthermore, the use of plastics material for the walls defining the fluid reservoir in combination with a suitably designed metering device means that fluids other than oil may be used within the damper.

[0009] In this regard, when the reservoir wall is made of, for example, steel, it is necessary to use oil as the working fluid because this prevents corrosion that would occur with many alternative fluids. However, when the reservoir wall is made of a plastic material, the buffer's working fluid can be selected without concern for its effect in causing corrosion of ferrous metals.

[0010] This in turn means that a fluid may be chosen which is lighter and cheaper than the oils which have been used hitherto. Indeed, when the walls defining the reservoir are made of plastic material, it may be possible to consider using a ubiquitous fluid such as water as the working fluid of the buffer. This may mean that in some cases it is easier to install the buffer than before; furthermore, the building water supply may be used to fill it (rather than a container of special oil); and furthermore, the step of filling the buffer may not need to be done when the buffer is manufactured, but may be left until installation takes place. Thus, the shipping costs and the purchase price of the buffer are further reduced.

[0011] Many other non-oil fluids besides water may alternatively be employed; and the features of the damper of the present invention do not preclude the use of oil where necessary.

[0012] Mixtures of fluids may be used to produce specific performance effects. For example, one may consider mixing an antifreeze agent with another fluid to produce a buffer that can be used in cryogenic environments. Other fluid mixtures are also possible.

[0013] Various plastic materials are suitable for forming the at least one wall. As non-limiting examples, one may consider acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), polyoxymethylene (POM) or "acetal", or polypropylene, although any plastic material that provides manufacturing convenience and corrosion resistance is suitable.

[0014] The at least one wall may surround the compressible energy absorber over at least a portion of its length between the base recess and the cap recess. The plastic material may be readily formed into an encapsulated shape by any of a variety of processes, including but not limited to spinning, casting, pressing, molding, additive manufacturing (i.e., so-called "3D printing"), and related methods. All feasible methods of making the plastic wall are included within the disclosure herein.

[0015] Conveniently, the at least one wall comprises or consists of respective lower and upper wall sections, the lower wall section extending upwardly from the base member and the upper wall section extending downwardly from the cap. In such an arrangement, the at least one wall section may be formed as respective upwardly extending and downwardly extending extensions of the respective base and cap recesses.

[0016] When so formed as an extension of the base and cap recesses, the at least one wall is of two-part construction. The two sections may be made of the same material as the base and cap recesses and may be integral with the base and cap recesses; or they may be separate components. In the latter case, the sections of the wall portion may be formed of a different material than the recess. In some versions of the invention, one of the sections of the wall portion may be formed of the same material as the recess with which it is associated; and the other section may be formed of a different material. Various material combinations are possible, but in many examples of the invention, the extension defining the at least one wall is integral with the base member and cap and is formed of the same material as the base member and cap.

[0017] The lower wall segment may define an upward facing peripheral wall edge, and the upper wall segment may define a downward facing peripheral wall edge, the upward facing and downward facing wall edges having the same size and shape and contacting each other around the periphery of the reservoir, thereby providing an uninterrupted wall segment near the upward facing and downward facing wall edges; and the upper and lower wall segments are fixed to each other.

[0018] This arrangement allows the sections of the at least one wall to be reliably positioned and easily secured to each other. The securing may be achieved by any of a wide range of means, including fasteners, clips, threads and other forms of locking arrangements. Such means may be releasable, or they may be of a type that once secured is permanently secured.

[0019] In particularly preferred embodiments, the bumper comprises adhesive material on one or both of the upwardly facing and downwardly facing wall edges to thereby secure the upper and lower wall sections to one another.

[0020] One of the lower and upper wall sections may include a relatively large area end section, and the other of the lower and upper wall sections may include a relatively small area end section, whereby the relatively small area end section may be received within the relatively large area end section in a manner that positions the upper and lower wall sections relative to each other to define the at least one wall.

[0021] This aspect of the utility model allows easy assembly of wall segments to define a single reservoir wall. This is beneficial in a mass production environment, for example, where the buffer is assembled. In addition, this aspect is compatible with various options for fixing the wall segments together as outlined above.

[0022] The relatively small area end section may be a friction, press fit or interference fit within the relatively large area end section. This aspect, when present, further contributes to making the reservoir wall easy, quick and reliable to assemble from discrete components. Additionally or alternatively, the base member and the cap may be welded together. This may be achieved by any of a range of methods, such as friction welding and ultrasonic welding.

[0023] In an alternative embodiment, optionally, the bumper comprises at least one intermediate wall member extending between the base recess and the cap recess so as to define at least a portion of the length of the closed reservoir.

[0024] An intermediate wall member may be provided to interconnect the above-mentioned lower and upper wall sections. To this end, the intermediate wall member may have the same cross section at its ends as the corresponding lower or upper wall end section positioned adjacent thereto.

[0025] In practice, the intermediate wall member may have a constant internal cross-section along its length, and more preferably may be a hollow chamber having the same internal shape as the lower and upper wall sections (assuming these have the same shape as each other in an alternative embodiment, although this need not be the case). The intermediate wall member is made of or comprises a plastic material. This may be the same material as the material of the lower and upper wall sections, although this need not necessarily be the case.

[0026] The lower wall section may define an upwardly facing peripheral wall edge and the upper wall section may define a downwardly facing peripheral wall edge. The intermediate wall member may define a respective intermediate wall end at each of its ends, the respective intermediate wall end having a wall end edge that is in contact with, secured to, and of the same respective size and shape as at least one of the upwardly facing and downwardly facing wall edges around the periphery of the reservoir to thereby provide an uninterrupted wall section in the respective vicinity of the wall end edges.

[0027] Similarly, the bumper may include adhesive material on at least one of the upwardly facing peripheral wall edge, the downwardly facing peripheral wall edge and one or more of said wall end edges to thereby secure the elements defining the closed reservoir to each other.

[0028] Thus, the intermediate wall member may advantageously be fixed in a similar manner as the fixing of the lower and upper wall sections to each other as explained above.

[0029] Additionally, the lower wall segment and an intermediate wall member adjacent the lower wall segment may be shaped and sized such that one is receivable within the other in a manner that positions the lower wall segment and intermediate wall member relative to each other to define a portion of the at least one wall.

[0030] Moreover, the upper wall segment and the intermediate wall member adjacent to the upper wall segment may be shaped and sized such that one is receivable within the other in a manner that positions the upper wall segment and the intermediate wall member relative to each other to define a portion of the at least one wall.

[0031] This is again somewhat similar to the arrangement for positioning lower and upper wall sections as described above, but with the insertion of intermediate wall members.

[0032] Optionally, the elevator buffer includes a foot defined at or near a lowermost end of the elevator buffer in use, and one or more ribs or fillets extending between and secured to the foot and an upwardly extending base recess.

[0033] Providing feet is one way to ensure that the elevator buffer is stably supported on the floor of the elevator shaft from below. However, other arrangements (such as a hole extending downwardly into the material of the shaft and into which a stable downwardly extending portion of the housing can be received) are possible within the scope of the present disclosure.

[0034] Conveniently, the compressible energy absorber is or comprises a fluidic energy absorber which, in use, contains an energy dissipating fluid. However, other forms of energy absorbers are not excluded, such as elastically deformable elements. These may be provided as an alternative to or in combination with the fluidic energy absorber.

[0035] Desirably, the fluid reservoir may contain, in use, an energy dissipating fluid, and the buffer may include one or more conduits via which the energy dissipating fluid may be supplied between the fluid reservoir and the compressible energy absorber.

[0036] Conveniently, the energy dissipating fluid is selected from the list comprising: oil and water. Preferred oils (when present) include but are not limited to hydraulic oil or its equivalent.

[0037] In addition, the compressible energy absorber may additionally include a hollow metering chamber, which is received in the fluid reservoir over at least a portion of its length; and a piston fixed to the rod, which is sealingly movably received in the metering chamber, the metering chamber including one or more holes, the one or more holes leading to the interior of the metering chamber and outside the metering chamber, thereby interconnecting the interior and exterior of the metering chamber; and an elastically deformable member, which in the absence of an applied force imparts a biasing force that biases the piston toward the upper part of the metering chamber in use, arranged so that when a force is applied longitudinally to the rod to compress the compressible energy absorber, the piston overcomes the force generated by the elastically deformable member and moves toward the lower part of the metering chamber in use, while discharging fluid from the metering chamber to the fluid reservoir via the one or more holes; and when the applied force decreases to a magnitude less than the biasing force, the elastically deformable member biases the piston back toward the upper part of the metering chamber. Therefore, the energy absorber can advantageously be of a universal type.

[0038] In a practical but optional embodiment, the elevator buffer may include a plurality of apertures formed spaced apart from one another around a perimeter defined by the metering chamber and / or along a length longitudinally defined by the metering chamber.

[0039] At least one of the holes may have a smaller cross-sectional area at its opening into the interior of the metering chamber than at its opening at the exterior of the metering chamber.

[0040] The elevator buffer may include one or more energy dissipating elements within the fluid reservoir outside the metering chamber, which are contacted by the fluid discharged through one or more of the holes in a manner that dissipates energy in the energy dissipating fluid when the compressible energy absorber is longitudinally compressed.

[0041] The use of a plastic material to manufacture the one or more walls allows for the fluid reservoir to be easily designed and manufactured in a manner that accommodates the one or more energy dissipation elements. Such elements may include one or more movable components that are moved when contacted by fluid discharged from the energy absorber, and due to the manufacture of the at least one wall, such features may be easily mounted or otherwise accommodated, and in many examples, the entire housing is made of a plastic material.

[0042] More particularly, the one or more energy dissipation elements may be selected from a list comprising: one or more baffles positioned to intersect and reactively reduce the energy of fluid discharged through the one or more holes during compression of the compressible energy absorber; and one or more rings rotatably held relative to the exterior of the metering chamber and comprising one or more blades positioned to intersect and reactively reduce the energy of fluid discharged through the one or more baffles during compression of the compressible energy absorber through rotational acceleration of the one or more rings.

[0043] Additionally, at least one of the apertures may be angled relative to a horizontal plane in use, thereby reactively dissipating energy in the fluid expelled via the one or more apertures during compression of the compressible energy absorber.

[0044] For the avoidance of doubt, as used herein, the term "elevator" is synonymous with "lift" as used in some jurisdictions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Preferred embodiments of the present invention will now be described by way of non-limiting examples with reference to the accompanying drawings, in which:

[0046] Figure 1 is an isometric partial cross-sectional view of a first embodiment of an elevator buffer according to the present invention;

[0047] Figure 2 yes Figure 1 a side view of the buffer;

[0048] Figure 3 is Figure 2 A cross-sectional view taken on line YY of ;

[0049] Figure 4 is an isometric partial cross-sectional view of a second embodiment of an elevator buffer according to the present invention;

[0050] Figure 5 yes Figure 4 a side view of the buffer;

[0051] Figure 6 is Figure 5 A cross-sectional view taken on line WW of FIG.

[0052] Figure 7 is with Figure 3 A similar cross-sectional view showing Figure 1 optional energy dissipation elements in the form of a stacked series of rotatable blade support disks in the buffer;

[0053] Figure 8is formed Figure 7 an enlarged perspective view of one form of a disk of a portion of an embodiment;

[0054] Fig. 9 is with Figure 7 a similar cross-sectional view and showing, as an alternative to the rotatable disk, a spray shield that helps dissipate energy in the fluid being discharged through the ports visible in the figure; and

[0055] Fig.10 is with Figure 7 and Fig. 9 A similar cross-sectional view and showing the angle of the metering port of the energy absorber as a further means of dissipating fluid energy. DETAILED DESCRIPTION

[0056] Referring to the drawings and first to Figures 1 to 3 , an elevator buffer 10 according to an embodiment of the present invention is shown.

[0057] The elevator buffer 10 comprises a base member 11 which defines a hollow base recess 12 which extends upwardly in use. In the illustrated embodiment, the base recess 12 is defined by an upright, continuous, constant thickness, obliquely upwardly extending cylindrical wall (lower wall section) 13 as an upright hollow cylinder of gradually increasing diameter along its upwardly extending length. However, the recess 12 may take a range of other forms, including, for example, a polygonal cross section over part or all of its length; a constant or other non-constant cross section, a non-constant wall thickness, formed by more than one wall, and various other modifications, as will be apparent to those skilled in the art.

[0058] The base recess 12 receives a lower end of a compressible energy absorber 14 extending vertically upward therein, as will be described in greater detail below.

[0059] The elevator buffer 10 also includes a cap 16, as further described below, which fits onto the top of the base member 11 and is thus substantially located above the base member. When so fitted together, the cap 16 and the base member 11 define a housing. The interior of the housing serves as a container for the energy absorber 14 and as a reservoir for a fluid, also described below.

[0060] In the illustrated embodiment, the cap 16 is formed as an upwardly extending truncated cone at its exterior, the lower end of which has a smaller diameter than the upper end. The cap 16 is formed at its uppermost end to include a circumferential lip 17 that protrudes upward around the outer periphery of the upper end.

[0061] In a similar manner to the base member 11 , these design aspects of the cap 16 are not mandatory, and many construction variations (as will occur to those skilled in the art) are possible within the scope of the present invention.

[0062] Radially inward of the lip 17, the cap 16 includes an annular groove 18 that is recessed downward relative to the lip 17. Radially inward of the groove 18, the cap 16 extends upward beyond the height of the lip 17 to define a cylindrical housing extension 19. In the illustrated embodiment, due to the circular cross-section of the cap 16, the lip 17 and the groove 18 are circular. However, this need not be the case, and other shapes of the lip 17 and the groove 18 are possible. The lip 17 and the groove 18 do not have to have the same shape. More generally, the base member 11 and the cap 16 do not have to have a circular cross-section, although this form is advantageous due to factors such as its inherent strength and the ease with which it can be manufactured.

[0063] A series of reaction surface webs 21 are arranged around the interior of the lip so as to rigidly interconnect the lip 17 with the material of the housing extension and thereby collectively define a base member in the slot 18. The reaction surface webs 21 are equiangularly spaced about a circle defined by the interior of the slot and each reaction surface web presents an upwardly facing upper edge reaction surface 21a, as shown in FIG. Figure 3 The reaction surface 21a is used to react to the force applied by the elastically deformable member, which in the illustrated embodiment is a coil spring 22. The function of the spring 22 is described below.

[0064] Forming the reaction surface by a series of webs 21 defining an upwardly facing upper edge means that the material of the cap can be minimized while providing a design that can be easily manufactured using, for example, molding or other mass production techniques. However, the one or more reaction surfaces 21a may be designed in different ways, such as without equiangularly spaced webs or similar features; without webs or similar features all having the same design as shown; or as a continuous bottom plate defining an annular bottom portion of the groove 18. Other forms of reaction surfaces are also possible, as will occur to those skilled in the art.

[0065] The cap 16 has a hollow interior defined by a downwardly depending, substantially cylindrical wall (upper wall section) 20 and this defines a downwardly extending cap recess 15. This is intended to receive an upper portion of a body 30 of the energy absorber 14.

[0066] The foregoing corresponds to an arrangement in which the at least one wall is formed by the respective lower wall section 13 and upper wall section 20 described above.

[0067] The lower wall section 13 defines an upwardly facing peripheral, i.e., circumferential (annular) wall edge 13a adjacent its uppermost end. The upper wall section 20 defines a downwardly facing peripheral, i.e., circumferential (annular) wall edge 20a. The wall edges 13a, 20a are of the same size and are positioned on the respective walls 13, 20 so as to contact each other when the cap 16 is positioned over the base member 11 to form the housing of the elevator buffer 10. As a result, at least on the inner side of the housing, the walls 13, 20 define a wall section that is uninterrupted in the up-down and circumferential directions about the respective wall edges 13a, 20a.

[0068] However, as shown, the lower and upper wall sections 13, 20 need not be cylindrical, and may instead have different (e.g., polygonal) cross-sectional shapes, such as may correspond to the overall shape of the associated base member 11 or cap 16. It can be seen that the wall edges 13a, 20a may similarly have different cross-sectional shapes, although they are the same as the corresponding lower or upper wall sections 13, 20. However, the lower and upper wall sections 13, 20 (and the corresponding wall edges 13a, 20a) preferably have the same cross-sectional shapes as each other, as shown in the illustrated embodiment.

[0069] Additionally, in the embodiment shown, the upper and lower wall sections 13, 20 are secured together. In the illustrated embodiment, this is accomplished by the presence of an applied adhesive material that secures the wall edges 13a, 20a to one another. During assembly of the elevator buffer 10, the adhesive material may be applied to one or both of the wall edges 13a, 20a, as may be dictated by the precise design and assembly requirements of the buffer 10. Various methods of applying the adhesive material are possible and will be known to those skilled in the art.

[0070] As an alternative or in addition to the use of adhesive materials, the base member 11 and cap 16 may include other fixing means. These may take the form of one or more clips, fasteners, threads and other forms of locking arrangements without limitation. Ultrasonic or heat welding of the materials of the base member 11 and cap 16 may additionally or alternatively be employed, and the applicability of these methods of securing the components together is another unexpected advantage of using plastic materials in the construction of the elevator buffer 10.

[0071] The securing means may be releasable or they may secure the base member 11 and cap 16 together, such as permanently.

[0072] As from Figure 3 As will be apparent, the base member 11 adjacent the wall edge 13a is arranged to have a relatively small diameter, and hence relatively small area, end section. The lowermost portion of the cap 16 adjacent this has a relatively large diameter, and hence relatively large area.

[0073] The portions of the elevator buffer 10 are sized such that the upper end of the base member 11 is received within the lower end of the cap 16 in a manner that positions the lower and upper wall sections 13, 20 relative to each other and defines the at least one wall mentioned.

[0074] The described arrangement may be such that the protruding portion of the base member 11 (i.e., the relatively small area end section thereof) is friction, interference, or force fit in the relatively large area end section of the cap 16. Such an arrangement may be designed so that it is possible to manually assemble the base member 11 and the cap 16. Likewise, it is within the scope of the present invention to assemble the components together using one or more tools and / or machines.

[0075] The compressible energy absorber 14 has a body 30 which is an elongated, hollow, upright cylinder in use, having a cylindrical internal metering chamber 25 of constant internal diameter, and having a cylindrical piston 23 movably (especially slidably) received therein so as to be movable along the length of the interior of the body 30. However, other shapes of the body, metering chamber and piston are possible.

[0076] The piston 23 includes one or more o-ring grooves 24, 26 formed in its outer surface for receiving piston rings 27, 28 (i.e., sealing rings), which combine with the outer diameter of the piston 23 and the inner diameter of the metering chamber 25 to ensure fluid-proof sealing of the piston 23 relative to the inner wall of the metering chamber 25.

[0077] The body 30 of the energy absorber 14 is received within the space defined by the base recess 12 and the cap recess 15, wherein as mentioned the lower end of the body 30 is in the base recess 12 and the upper end is in the cap recess 15. Since the cap 16 is assembled on top of the base member 11, this space is a single volume, which is substantially cylindrical in the embodiment shown, although this need not necessarily be the case in other embodiments. In the preferred embodiment shown, the lower portion of the single volume defined by the base recess 12 has a larger diameter than the upper portion of the space defined by the cap recess 15, although this need not necessarily be the case in other embodiments.

[0078] The base recess 12 is defined by an upwardly extending lower wall 13, and the cap recess 15 is defined by a downwardly depending upper wall 20. These walls collectively correspond to at least one wall defining the aforementioned space. This serves as a substantially closed reservoir 31 for fluid, which extends between the base member 11 and the cap 16.

[0079] The piston 23 is connected at its upper end to a rod 29 extending upwardly therefrom.

[0080] The upper end of the reservoir 31 is substantially closed by the cap 16, but is perforated by a hole 32 extending therethrough. The rod 29 passes through the hole 32 above its connection with the piston 23 so that it emerges on the upper side of the cap 16. A stabilizer bushing 35, which in the illustrated embodiment is an annular member fixed to the hole 32, but which may take other forms in other embodiments, tightly surrounds the rod 29 in a manner that allows the rod to move in the hole while ensuring a fluid-tight seal with the rod 29 during operation of the buffer 10.

[0081] The rod 29 extends beyond the upper end of the cap 16 by a distance determined by the design of the compressible energy absorber 14. In this regard, the intended duty of the elevator buffer is important. In particular, in elevator buffer design, it is important to match the stroke length to the expected speed of the elevator car, the movement of which is to be buffered. This might suggest extending the rod as much as possible, but a rod that is too long might make the buffer laterally unstable and in any case would add unnecessary mass to the buffer 10. The rod length is optimized at the design stage taking these factors into account.

[0082] A reaction member in the form of a rigid circular disc 33 is secured to the rod at its uppermost end. The disc 33 is formed with an outer downwardly depending circular rim wall 34 and a downwardly depending central boss 36 at which it is secured to the rod 29. In the radial region between the rim wall 34 and the boss 36, the disc 33 defines an upwardly extending annular recess 37, the purpose of which is to receive the upper end of the spring 22 against it from below.

[0083] The base member 11 includes a flat bottom foot 45 extending outwardly therefrom. In the illustrated embodiment, the foot 45 is square in plan view, although a variety of other shapes are possible.

[0084] The foot 45 is rigidly fixed to the base member 11 and in some embodiments is integrally formed with the base member and extends outwardly from its lowermost end. A series of fixing holes 50 are formed to extend through the material of the foot 45 at each corresponding corner. Optional eyelets 51 reinforce the foot 45 near the holes 50.

[0085] The purpose of the feet 45 is to help the elevator buffer 10 stand stably and upright on the surface of the elevator shaft. One or more bolts or studs can be used in a manner extending through the holes 50 to secure the buffer 10 in place below the elevator car.

[0086] A series of rigid triangular moldings 52 are secured around the outer perimeter of the base recess 12 and connected to the feet 45. The moldings 52 are an optional feature that helps to strengthen the housing in the vicinity of the feet 45.

[0087] The components of the elevator buffer 10 described so far may be made of a variety of materials. The body 30 of the compressible energy absorber 14, the piston 23, the rod 29 attached thereto, and the disc 33 may be made of steel material and may be rigidly fixed to one another using techniques known per se.

[0088] However, an important aspect of the present invention is that at least the upwardly extending wall 13 and the downwardly depending wall 20 are manufactured from a plastics material, defining at least one wall therebetween which in turn defines a substantially closed reservoir 31 .

[0089] In fact, Figures 1 to 3 In the embodiment, as mentioned the entire base member 11 and the cap 16 are made of plastic material.

[0090] The advantages of such materials (exemplary non-limiting grades of which are mentioned herein) are as described above. In particular, the use of plastic materials allows for the formation of elevator buffers that are significantly lighter than the lightest all-metal buffers currently on the market, while surprisingly maintaining and in some respects improving performance levels comparable to all-metal buffers.

[0091] The metering chamber 25 is, at least internally, an elongated hollow cylinder of constant inner diameter, although in other embodiments the metering chamber may have a different shape. In any case, in the embodiment shown, the metering chamber 25 is constituted by the body 30 of the energy absorber 14 together with an end cap 38 sealingly fitted into the lowermost end of the chamber 25. The end cap 38 rests on the bottom inside the base recess 12. The latter may be shaped as shown in the figure so as to act to precisely position the energy absorber 14 relative to the base member 11.

[0092] As illustrated, the at least one wall defined by the walls 13, 20 is preferably cylindrical at least on its inner surface, although the inner diameter of the reservoir 31 partially decreases along its length in an upward direction due to the design of the base member 11 and the cap 16. Other shapes and sizes of the reservoir 31 are possible, as will occur to those skilled in the art. As illustrated, the reservoir 31 surrounds the compressible energy absorber 14 over a portion of its length, and the compressible energy absorber is composed of a body 30 located between the base recess 12 and the cap recess 15.

[0093] At the upper end of the body 30, a space is formed to locate the body 30 relative to the cap 16. The locating features of the base member 11 and the cap 16 facilitate assembly of the elevator buffer 10 as a mass-produced item.

[0094] The body 30 includes a series of metering holes 39 extending therethrough to interconnect the interior and exterior of the compressible energy absorber 14. In the illustrated embodiment, the holes 39 are arranged in four vertical lines of four holes each extending along the length of the body 30 below the piston 23 when the piston is located at the top of the metering chamber 25. In the illustrated embodiment, the four lines of holes 39 are mutually orthogonal.

[0095] Other patterns and numbers of holes 39 are possible within the scope of the present invention, but the foregoing has been found to be a very effective arrangement.

[0096] Each hole 39 is a relatively narrow cylindrical bore, which opens inside the metering chamber 25. Each of the holes widens to become a larger diameter bore that opens on the side on the outside of the body 30. The reason for this configuration is as described above.

[0097] Other designs (eg, cross-sectional shapes of the holes 39 ) are possible within the scope of the present invention.

[0098] The metering chamber 25 is filled with a working fluid which may be of the kind exemplified herein.

[0099] When the elevator car overshoots the lowest expected travel range by more than a predetermined, desired minimum amount, the underside of the elevator car or an element fixed thereto contacts the rod 29 from above. This creates a downward force that is transmitted to the piston 23 via the rod 29. Assuming that this force is greater than the biasing force applied by the spring 22, this causes the piston 23 to move downward within the metering chamber 25. The size of the metering chamber 25 and the piston 23, together with the action of the sealing rings 27, 28, causes the piston 23 to press against the working fluid.

[0100] The spring 22 now becomes compressed between the disk 33 and the cap 16. This increases the potential energy in the spring 22.

[0101] The working fluid in the metering chamber 25 is incompressible. Therefore, the movement of the piston 23 forces it into the fluid reservoir 31 via the metering hole 39 at high speed. During this process, the energy of the piston 23 and thus the overshooting elevator car is dissipated in the working fluid.

[0102] When the piston 23 descends in the metering chamber 25, it continuously covers the hole 39, which, as mentioned, is formed as a vertical line in the illustrated non-limiting embodiment. This means that the deeper the piston 23 descends, the smaller the volume through which the working fluid can leave the metering chamber 25, while the resistance provided by the elevator buffer 10 increases accordingly.

[0103] This in turn means that the degree of energy damping provided by the buffer 10 is automatically adjusted according to the energy of the pulse applied by the elevator car to the rod 29. A higher energy pulse requires more damping than a lower energy pulse. This causes the piston 23 to drop further than in the case of a smaller energy pulse, resulting in an increase in the resistance provided by the buffer 10 in relation to the prevailing energy dissipation requirement.

[0104] Once all the energy of the elevator car pulse has been dissipated, the elevator car will be at rest and an automatic system forming part of the elevator installation will apply the elevator brakes to ensure that the elevator car is stable and not prone to accidental movement while passengers etc. exit and board the elevator car.

[0105] When any desired boarding and exiting has occurred, a travel command has been entered, and all elevator doors or other safety barriers have been closed, the elevator car will now rise under the power of the motor (which is an essential part of all such modern systems), thereby lifting off the rod 29. At this point, the spring 22 decompresses, converting its potential energy into kinetic energy, and pushing the disc 33 upward.

[0106] Due to the rigid connection represented by the rod 29, this simultaneously pulls the piston 23 upwards within the metering chamber 25 until movement of the piston 23 is arrested by contact with the bushing 35 at the top of the cap 16. Because the hole in the bushing 35 has a smaller diameter than the outer diameter of the piston 23, the piston cannot pass through the hole 32 and is held at the top of the metering chamber 25 by the biasing force of the spring 22.

[0107] As piston 23 moves upward, the low fluid pressure created at its lower end draws working fluid from reservoir 31 back into metering chamber 25 via orifice 39. When piston 23 is at the top of metering chamber 25, elevator buffer 10 is ready to be restroked by a subsequent elevator car pulse.

[0108] The cap 16 includes a switch housing 41 fixed to one side, which houses an electrical switch. The switch includes a spring-biased actuator element 42 that projects horizontally and terminates in an engagement member. In the illustrated non-limiting embodiment, this takes the form of a cam 43 (although other designs are possible). The spring bias of the actuator element 42 pushes it to a protruding position.

[0109] The cam 43 is mounted to rotate about a horizontal axis. A rigid (e.g., metal or other rigid material) striker 44 is fixed to a position on the outer edge of the disk 33 and extends downward from this position toward the vicinity of the cam 43. The striker 44 passes through a guide slot 47 formed in a guide plate 48 that protrudes outward from the cap 16 and under which the switch housing 41 is mounted. The lowermost end of the striker 44 terminates at a chamfered cam surface 46 adjacent to the cam 43.

[0110] The shape of the chamfer is such that when the piston 23 is at the top of the metering chamber 25 , the chamfer clears the cam 43 and causes the actuator element 42 to be fully extended out of the housing 41 by its spring bias.

[0111] In this configuration, the switch is connected so as to signal a normal condition of the elevator buffer 10 because the piston 23 is at the top of the metering chamber 25 so that the full stroke of the elevator buffer 10 is available for energy dissipation.

[0112] When the pulse of the elevator car drives the disc 33, rod 29 and piston 23 downward, this simultaneously causes the striker 44 to descend through the guide slot 47. This causes the chamfered cam surface 46 to engage the cam 43 and exert a horizontal force on it. This in turn causes the actuator element 42 to be pushed into the switch housing 41 against its spring bias, thereby changing the state of the switch. The switch then signals that less than a full stroke of the buffer 10 is available.

[0113] In a typical setting, the switch is configured so that the switch is closed when the actuator element 42 is fully extended, and the switch is open when the actuator element becomes pushed any appreciable distance into the switch housing 41. Thus, a positive signal voltage is considered an indicator that the full buffer stroke is available for energy dissipation. However, the switch can be configured in the opposite manner, so that an open switch configuration can be used to indicate that the full stroke is available.

[0114] The signals generated by the switches are transmitted to the control circuitry of the elevator installation via appropriate wiring (which is omitted from the figure for clarity). Sometimes, when the elevator buffer is compressed so that the state of the switch changes as described, the arrangement may be such that power to the motor is temporarily disconnected.

[0115] This ensures that an overshooting elevator car is not driven further to overshoot the minimum expected travel range. Furthermore, if the elevator buffer cannot return to its fully extended length when the elevator car is lifted off the rod 29 for some reason (such as the piston 23 sticking in the metering chamber 25), this may be potentially dangerous because the energy absorption capacity of the buffer 10 may be reduced as a result. In such a situation, the switch can signal the reduction in efficiency of the buffer 10 by more permanently de-energizing the motor before repair or replacement of the buffer 10 or at least the compressible energy absorber 14 is achieved.

[0116] Figure 4 , Figure 5 and Figure 6 The second embodiment of the elevator buffer 110 within the scope of the present invention is Figure 1 , Figure 2 and Figure 3 Similar view.

[0117] The construction of the second embodiment is identical in most respects to that of the first embodiment. Several components of the second embodiment are similar or identical to corresponding components of the first embodiment. These will not be described in detail with respect to the second embodiment. Figure 4 , Figure 5 and Figure 6 When necessary, Figure 1 , Figure 2 and Figure 3 The same reference numerals are used to identify several of these components.

[0118] exist Figure 4 , Figure 5 and Figure 6 In the embodiment, there is provided Figure 1 , Figure 2 and Figure 3 The corresponding parts in the figure are the same as the base member 11 and the cap 16.

[0119] However, Figure 4 , Figure 5 and Figure 6 The elevator buffer 110 and Figure 1 , Figure 2 and Figure 3 The second embodiment of the elevator buffer is slightly longer than the first embodiment. This is because the second embodiment of the elevator buffer is required to withstand greater forces than the first embodiment. This is achieved by providing an extended compressible energy absorber 114 within the extended housing.

[0120] The energy absorber 114 has substantially the same Figure 1 , Figure 2 and Figure 3The energy absorber 14 is of the same construction except that the body 130, rod 129 and striker bar 144 are longer.

[0121] The additional length of the body 130 is accommodated by the presence of the intermediate wall member 149. This is an elongated, constant inner diameter hollow cylinder formed of a plastic material, although other cross-sectional shapes of the intermediate wall member are possible (e.g., if desired) to correspond to the cross-sectional shape of one or more of the lower wall section 13 and the upper wall section 20. In some embodiments, the plastic material from which the intermediate wall member 149 is formed will be the same as the material of the base member 11 and the cap 16. However, this need not necessarily be the case; and particular performance effects (such as, but not limited to, insulation or heat transfer effects, radio frequency shielding effects, or mechanical effects (such as preferred stiffness values ​​or vibration absorption characteristics)) can be achieved by selecting a material for the intermediate wall 149 that is different from the material of the base 11 or the cap 16.

[0122] In the embodiment shown, the intermediate wall member 149 is connected at its lower end to the Figures 1 to 3 This edge is contacted in a similar manner to the way in which the wall edge 20a contacts the upper wall edge 13a of the wall 13 of the base member 11.

[0123] The intermediate wall member 149 is formed at its upper end with Figures 1 to 3 The wall edge 13 a contacts the lower wall edge 20 a of the wall 20 of the cap 16 .

[0124] The intermediate wall member 149 may be secured at its upper and lower ends by using an adhesive material, for example between the wall ends. Figure 4 , Figure 5 and Figure 6 The options for applying the adhesive are essentially the same as those described above with respect to Figure 1 , Figure 2 and Figure 3 Additionally or alternatively, the above with respect to Figure 1 , Figure 2 and Figure 3 Other fastening means as described may be used to secure the ends of the intermediate wall member 149 in place.

[0125] As from Figure 6 As will be apparent, the uppermost portion of the base member 11 is sized to be received within the interior of the column defined by the intermediate wall member 149. The intermediate wall member 149 is similarly received within the lowermost portion of the cap 16 at its uppermost end.

[0126] In addition to the above changes, Figure 4 , Figure 5 and Figure 6 The elevator buffer 110 is basically the same as Figure 1 , Figure 2 and Figure 3 The buffer 110 is the same as the buffer 10. Figure 1 , Figure 2 and Figure 3 The buffer 10 of FIG. 1 functions in a very similar manner. For this reason, it is not necessary to repeat here the description of the sequence of operation of the buffer 110. Rather, the description of the sequence of operation of the first embodiment applies to the second embodiment, making any necessary minor changes to take into account the differences between the two embodiments.

[0127] Reference now Figure 7 , a variant 210 of the first embodiment of the elevator buffer is shown in a partially sectional view, in which a series of rotatable baffle rings 53a, 53b, 53c, 53d, 53e are arranged stacked on top of each other in the base recess 12.

[0128] like Figure 8 As best shown in the enlarged view of , each baffle ring 53 is an annular member of a rigid material (such as light metal) (although other shapes are possible) which is formed by pressing or a similar forming process into an annular series of flat-topped serrated uprights 54, which are spaced from each other by intermediate flat-bottomed crenels 56, which also define an annular series.

[0129] The material of the baffle ring 53 interconnecting the tops of the upstands 54 with the crenels 56 extends as vertically extending walls 57 on each side of the flat top of each upstand.

[0130] The baffle rings 53a to 53e are stacked within the base recess 12, with the main body 230 of the energy absorber 214 extending upward within the resulting stack and acting as a core.

[0131] The material of the baffle rings 53 is such that they can slidably rotate on top of one another, with the lowermost ring 53 a being slidably rotatable on the material of the base member 11 .

[0132] When the buffer 210 is compressed due to contact by the lower side of the elevator car, the working fluid discharged from the metering chamber 225 through the holes 239 impacts the baffle rings 53 adjacent to the corresponding holes 239 and rotates them. This is mainly due to the influence of the fluid on the vertically extending wall 57 acting laterally.

[0133] The energy required to rotate the baffle ring 53 increases the energy dissipation in the working fluid, thereby increasing the efficiency of the elevator buffer 210.

[0134] Figure 7 An additional optional feature that may be employed in any embodiment of the present invention is shown. This is a generally irregular pattern of holes 239.

[0135] like Figure 7 As can be seen in FIG. 2 , the series of holes 239 on the left includes three holes in a vertical line. The series on the right also includes three holes in a vertical line, but none of these holes are aligned with any of the holes in the series on the left in the horizontal direction.

[0136] exist Figure 7 The central series of holes 239 visible at the opposite end of the lens comprises four holes in a vertical line. None of these holes is aligned horizontally with any of the series of holes 239 on the left and the series of holes 239 on the right.

[0137] A further series of holes may also be provided opposite the central series, but as the view is in section in this figure, these holes are Figure 7 It is not visible.

[0138] Figure 7 The irregularity of the holes in is illustrative and does not limit the present invention. Therefore, a wide range of additional changes to the number and positioning of holes 239 are possible. Including Figure 7 One reason for the irregular pattern is to ensure that a predetermined amount of working fluid force is directed toward each of the baffle rings 53. As will be apparent, the baffle rings 53d and 53e toward the top of the stack of rings will receive a greater fluid flow than those baffle rings lower in the stack unless the impulse experienced by the rod 29 is sufficient to cause the uppermost hole 239 to be covered.

[0139] Optionally, Figure 7 The holes 239 in any or all embodiments may be positioned in a generally spiral arrangement such that they are sequentially blocked by the piston 23 .

[0140] Figure 7 The cross section is in the same Figures 1 to 6 1 and 2, and illustrate another optional feature. This is a screw-in dipstick 58 that is inserted through a dipstick bore formed in the flange of cap 16. Dipstick 58 extends into working fluid reservoir 231 in a manner familiar to those skilled in the art and in accordance with its provision for assessing the level of fluid in working fluid reservoir 231. A dipstick such as dipstick 58 may be present in any embodiment of the present invention, including the first embodiment elevator buffer 10, and additionally in the embodiments described below. Fig. 9 and Fig.10 is visible in the implementation scheme.

[0141] Fig. 9 The elevator buffer 310 of the embodiment is similar to Figure 7Buffer 230, except that in this embodiment the baffle ring 53 is omitted and replaced by a jet shield 59. This is an annular hollow cylinder made of a rigid material that lines the reservoir 331 defined in the base recess 12 in such a way as to prevent the flow of fluid through the hole 339 and thereby increase the energy attenuation effect, while at the same time protecting the inner wall of the container 331 from the jet of high-pressure working fluid (which otherwise could damage or pierce the material of the base member 11 and the cap 16). Other shapes of the jet shield are also possible while still providing similar energy dissipation and protection effects.

[0142] exist Fig. 9 The type of hole 339 is similar to Figure 7 The same is true for the embodiments, but this is not mandatory and many variations in the number, alignment and pattern of holes are possible.

[0143] exist Fig.10 , a fourth embodiment of an elevator buffer 410 omits the energy attenuation features located externally to the body 430, and instead enhances the energy dissipation effect by upward tilting of the apertures 439 as shown. The change in the flow direction of the working fluid required to cause the working fluid to exit through such apertures increases the degree of attenuation.

[0144] Fig.10 The type and number of holes 439 in Fig. 9 , but this need not be the case, and many other numbers, types and alignments are possible.

[0145] For the avoidance of doubt, Figures 7 to 10 The attenuation enhancement features are optional, and they may be provided in any feasible combination with each other (if desired). Thus, for example Fig.10 The angled holes 439 can be used with Fig. 9 The spray shield 59 is provided in combination.

[0146] More generally the disclosure extends to all reasonable combinations of features as would be apparent to a person skilled in the art.

[0147] In summary, the present invention provides many unexpected advantages as described above.

[0148] The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an admission that the document is part of the current state of the art or is common general knowledge.

[0149] Unless the context dictates otherwise, preferences and options for a given aspect, feature or parameter of the invention should be considered disclosed in conjunction with any and all preferences and options for all other aspects, features and parameters of the invention.

Claims

1. An elevator buffer, characterized in that: The elevator buffer comprises: a base member defining a base recess extending upwardly in use, the base recess being used to receive a portion of a compressible energy absorber; a cap located above the base member in use, the cap defining one or more reaction surfaces for an elastically deformable member and a further downwardly extending cap recess for receiving a portion of the compressible energy absorber; a compressible energy absorber having respective sections received in the base recess and the cap recess; and at least one wall extending between the base recess and the cap recess. a plurality of lift elements, the plurality of lift elements comprising a plurality of walls being formed from or comprising a plastics material and defining a closed reservoir for a fluid extending between the base member and the cap, an aperture extending through the cap, the compressible energy absorber comprising a rod extending from the compressible energy absorber through the aperture, the rod comprising or having a reaction member fixed thereto, the reaction member being spaced apart from the or each reaction surface in use; and the lift buffer comprising a compressible, resiliently deformable member extending between the reaction member and the or each reaction surface.

2. The elevator buffer according to claim 1, characterized in that: The at least one wall surrounds the compressible energy absorber over at least a portion of its length between the base recess and the cap recess.

3. The elevator buffer according to claim 1 or claim 2, characterized in that: The at least one wall comprises or consists of respective lower and upper wall sections, the lower wall section extending upwardly from the base member and the upper wall section extending downwardly from the cap.

4. The elevator buffer according to claim 3, characterized in that: the lower wall segment defining an upwardly facing peripheral wall edge and the upper wall segment defining a downwardly facing peripheral wall edge, the upwardly and downwardly facing wall edges being of the same size and shape and contacting each other around the perimeter of the closed reservoir to thereby provide an uninterrupted wall segment proximate the upwardly and downwardly facing wall edges; And the upper and lower wall sections are fixed to each other.

5. The elevator buffer according to claim 4, characterized in that: The elevator buffer includes an adhesive material on one or both of the upwardly facing and downwardly facing wall edges to thereby secure the upper and lower wall sections to one another.

6. The elevator buffer according to any one of claims 3 to 5, characterized in that: One of the lower and upper wall sections includes a relatively large area end section, and the other of the lower and upper wall sections includes a relatively small area end section, whereby the relatively small area end section can be received within the relatively large area end section in a manner that positions the upper and lower wall sections relative to each other to define the at least one wall.

7. The elevator buffer according to claim 6, characterized in that: The relatively small area end section is a friction, press-fit, welded or interference fit within the relatively large area end section.

8. The elevator buffer according to any one of claims 1 to 4, characterized in that: The elevator buffer includes at least one intermediate wall member extending between the base recess and the cap recess to define at least a portion of the length of the closed reservoir.

9. The elevator buffer according to claim 8, characterized in that: The intermediate wall member interconnects the lower and upper wall sections.

10. The elevator buffer according to claim 9, characterized in that: The lower wall section defines an upward facing peripheral wall edge and the upper wall section defines a downward facing peripheral wall edge, wherein the intermediate wall member defines a corresponding intermediate wall end at each of its ends, the corresponding intermediate wall end having a wall end edge, the wall end edge being in contact with, secured to, and having the same corresponding size and shape as at least one of the upward and downward facing wall edges around the periphery of the closed reservoir to thereby provide an uninterrupted wall section in the respective vicinity of the wall end edges.

11. The elevator buffer according to claim 10, characterized in that: The elevator buffer includes adhesive material on at least one of the upward facing peripheral wall edge, the downward facing peripheral wall edge, and one or more of the wall end edges to thereby secure elements defining the closed reservoir to one another.

12. The elevator buffer according to claim 10 or claim 11, characterized in that: The shapes and sizes of the lower wall section and the intermediate wall member adjacent to the lower wall section are such that one is receivable within the other in a manner that positions the lower wall section and the intermediate wall member relative to each other to define a portion of the at least one wall.

13. The elevator buffer according to any one of claims 10 to 11, characterized in that: The shapes and sizes of the upper wall section and the intermediate wall member adjacent to the upper wall section are such that one is receivable within the other in a manner that positions the upper wall section and the intermediate wall member relative to each other to define a portion of the at least one wall.

14. The elevator buffer according to claim 1, characterized in that: The elevator buffer includes a foot defined at or near a lowermost end of the elevator buffer in use, and one or more ribs or fillets extending between and secured to the foot and the upwardly extending base recess.

15. The elevator buffer according to claim 1, characterized in that: The compressible energy absorber is or comprises a fluidic energy absorber which, in use, contains an energy dissipating fluid.

16. The elevator buffer according to claim 15, characterized in that: The closed reservoir contains, in use, an energy dissipating fluid, and wherein the buffer comprises one or more conduits via which the energy dissipating fluid can be supplied between the closed reservoir and the compressible energy absorber.

17. The elevator buffer according to claim 15 or claim 16, characterized in that: The energy dissipating fluid is selected from the list comprising: oil and water.

18. The elevator buffer according to claim 15, characterized in that: The compressible energy absorber additionally comprises: a hollow metering chamber, which is received in the closed reservoir over at least a portion of its length; and a piston fixed to the rod, which is sealingly and movably received in the metering chamber, the metering chamber including one or more holes, which lead to the interior of the metering chamber and open on the exterior of the metering chamber, thereby interconnecting the interior and exterior of the metering chamber; and the elastically deformable member, which, in the absence of an applied force, imparts a biasing force that biases the piston toward the upper portion of the metering chamber in use, arranged so that when a force is applied longitudinally to the rod to compress the compressible energy absorber, the piston overcomes the force generated by the elastically deformable member and moves toward the lower portion of the metering chamber in use, while discharging fluid from the metering chamber to the closed reservoir via the one or more holes; and when the applied force is reduced to a magnitude less than the biasing force, the elastically deformable member biases the piston back toward the upper portion of the metering chamber.

19. The elevator buffer according to claim 18, characterized in that: The elevator buffer includes a plurality of the holes formed spaced apart from each other around a perimeter defined by the metering chamber and / or along a length longitudinally defined by the metering chamber.

20. The elevator buffer according to claim 19, characterized in that: At least one of the holes has a smaller cross-sectional area at its opening into the interior of the metering chamber than at its opening at the exterior of the metering chamber.

21. The buffer according to any one of claims 18 to 20, characterized in that: One or more energy dissipating elements are included within the closed reservoir outside the metering chamber, and upon longitudinal compression of the compressible energy absorber, the one or more energy dissipating elements contact the fluid discharged through one or more of the holes in a manner that dissipates energy in the energy dissipating fluid.

22. The buffer according to claim 21, characterized in that: The one or more energy dissipating elements are selected from the list comprising: one or more baffles positioned to intersect and reactively reduce the energy of the fluid expelled via the one or more apertures during compression of the compressible energy absorber; and one or more rings rotatably held relative to the exterior of the metering chamber and including one or more vanes positioned to intersect and reduce the energy of fluid expelled via the one or more baffles during compression of the compressible energy absorber through rotational acceleration of the one or more rings.

23. The buffer according to claim 18, characterized in that: At least one of the apertures is angled relative to a horizontal plane in use to thereby reactively dissipate energy in fluid expelled via the one or more apertures during compression of the compressible energy absorber.

Images