AU595728B1 - Improved guide system in an hydraulic elevator - Google Patents

Description

COMMONWEALTH OF AUSTR7 2 8 FORM PATENTS ACT 1952 COMPLETE SPECIFICATION FOR OFFICE USE: Class Int.Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: "Priority: I~lReated Art: 00 00 0 0 0 0 6 0 0 0 0 o"NamMe of Applicant: OTIS ELEVATOR COMPANY Address of Applicant: Ten Farm Springs, Farmington, Connecticut oe 06032, United States of America 0 0o Actual Inventor: Richard J. Ericson and Jaime A. Rivera Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney 0 'mplete Specification for the Invention entitled: o* "IMPROVED GUIDE SYSTEM IN AN HYDRAULIC ELEVATOR" The following statement it: a full description of this invention, including the best method of performing it known to us:- S 1 1- Patent of Addition to 51309/85 dated 12th December, 1985 11 Fee: $190.00 ALLOWED 0 71!Z' Z5 09/ lq- Description Improved Guide System In An Hydraulic Elevator Technical Field This invention relates to elevators and particularly to holeless, hydraulic elevators.

o, o Background Art o 0 Short rise hydraulic elevators are well known in a 6 the art. Certain of such elevators comprise a car S" powered vertically by an hydraulic jack exposed 9 beneath the elevator car in a hole beneath the 0, hoistway. Provision of such a hole to accommodate the jack represents a significant portion of the cost of the erection of such an hydraulic elevator. In an 0 0 0o, effort to reduce the construction costs associated o .o5 with such prior art elevators, holeless hydraulic elevators have been developed. In such a holeless 0 0 elevator the car is powered by one or more hydraulic jacks, the cylinders of which are disposed generally alongside the car rather than beneath it, the lower ends of the jacks being received within a shallow pit ,0 at the bottom of the hoistway rather than in a deeper hole as described hereinabove. While the elimination of holes in hydraulic elevators has reduced the S- construction costs thereof, it has been determined that state of the art holeless hydraulic elevators still exhibit various shortcomings.

.jY SHELSTON WATERS PATENT ATTORNEYS CLARENCE STREET, SYDNEY

AUSTRALIA

Cables: 'Valid' Sydney Telex: 24422 2 2 A number of such shortcomings in present day holeless hydraulic elevators are associated with the elevator car frame which in some instances employs at the sides thereof, compressively loaded uprights with diagonal braces connected between the uprights and the car platform. It has been found that such car frames are not only complex, requiring rod fixtures on both the upright and car platform as well as means for 0,o0. adjusting rod tension, but are quite heavy as well.

Moreover, in such a frame structure, various components of the frame tend to be loaded in e Oi compression and bending which adversely affect the 0 stability of the car under operating conditions and I require accommodation by heavy structural members thereby further contributing to the weight of the frame. Such car frames also tend to militate against o 04 a ease of serviceability of the jacks since the upright o is often in a position which interferes with a it maintenance on the jack disposed adjacent thereto.

Prior art hydraulic elevators also exhibit various deficiencies in the support and stabilization of the car by the jacks and guide rails employed therein. Most of such deficiencies are attributable Sto the somewhat common approach of asymmetric support of the car by the jacks wherein, the jacks support the car by connection to the sides of the car frame either forwardly or rearwardly of the center thereof. Thus, 1 the weight of the car applies bending moments to the jacks and guide rails, thereby requiring burying of the lower ends of the jacks within the ground with an attendant risk galvanic corrosion of the jack l 3 cylinders as well as requiring heavy rails which add to the expense to the elevator in the cost of both materials therefor and erection thereof. Moreoever, prior art hydraulic elevators often fail to provide adequate yet economical means for limiting the overtravel of the elevator car (due to, for example, a malfunction of the hydraulic control system) while dissipating the kinetic energy of the car during such o° overtravel conditions.

0,.109 The above deficiencies associated with prior art *o hydraulic elevators combined with the desirability of mechanically simplifying such elevators while at the same time reducing the weight thereof has lead to the o present invention.

Disclosure of Invention OIt is therefore an object of the present invention to provide an hydraulic elevator of onhanced simplicity and stability and which is light in weight.

It is another object of the present invention to provide an hydraulic elevator which is compact and easily serviceable.

yf It is another object of the present invention to provide an hydraulic elevator characterized by an enhanced ease in the erection thereof.

-i 25 It is another object of the present invention to J 'provide an hydraulic elevator wherein overtravel of the elevator car due to malfunction of the hydraulic system is safely and simply limited.

In accordance with the present invention there 30 is provided an elevator comprising a car 4 powered by at least one hydraulic jack disposed adjacent to said car, said hydraulic jack including a cylinder and a plunger disposed therewithin for reciprocal movement with respect thereto, wherein: a guide shoe is disposed on said car, said guide shoe carrying at least one set of rollers having vertically spaced axes of rotation, said rollers bearing against the lateral surface of said jack cylinder for imparting enhanced stability, compactness and lateral load distribution to said elevator without necessitating a guide rail distinct from said jack cylinder.

S Brief Description of Drawings Figure 1 is an isometric view of a preferred o embodiment of the hydraulic elevator of the present invention, portions of the elevator being either broken away or removed entirely to show details of the construction thereof; ao figure 2 is a side elevation in partial section of one of the hydraulic jacks employed with the elevator of 200 the present invention; figure 3 is a view taken in the direction of line 3-3 of figure 2; figure 4 is an enlarged, fragmentary, elevation of the connection between one of the braces employed in the frame of the elevator car and the output member of the hydraulic jack and taken in the direction of line 4-4 of figure 1; figure 5 is an isometric view similar to figure 1, but showing an alternate embodiment of the hydraulic elevator in which lower portions of the guide rails thereof have been eliminated; figure 6 is a top plan view in partial section of a portion of the car frame and a guide shoe carried thereby, and an associated hydraulic jack, taken along line 6-6 of figure figure 7 is an enlarged, fragmentary, isometric view of a second alternate embodiment of the elevator in which lower portions of the guide rails have been eliminated; figure 8 is a partially sectioned, fragmentary top view of a third alternate embodiment of the elevator in which lower portions of the guide rails have been eliminated; and figure 9 is an enlarged isometric view of that portion of the elevator illustrated in figure 8.

.01, Best Mode for Carrying Out the Invention and Industrial Applicability Thereof Referring to figure 1, an hydraulic elevator 10 is °o disposed within a hoistway 15 including a sidewall a" structure 20 and a lower pit 25. The elevator itself o 0 C 0 comprises a car 30 including a frame 35, a sidewall structure (which for clarity is not illustrated) and a platform 40. The car is powered by a pair of upright jacks 45 disposed on opposite sides of the car and supported within hoistway 15 on the floor of pit d Car frame 35 comprises a pair of opposed side.frame assemblies each including a pair of oblique upwardly convergent braces 55 fixed at lower ends thereof to the car platform at opposed sides thereof. The braces may be of any known structural shape, in the preferred embodiment the braces being formed from tubular steel for strength and lightness. The lower ends of the braces are attached to the platform by riveted, bolted, or similar connections to L-shaped brackets 60 welded or similarly attached to .the sides of the platform. The upper ends of the braces are connected together by a rigidly bolted or riveted connection to opposite ends of bracket 65 of generally U-shaped cross section, the sides of bracket 65 each A including a cutout 70 which accommodates the head of jack therewithin. The connection between braces A 4 6 and bracket 65 is shown in greater detail in Fig. 4.

As shown therein, each brace is received within the interior of the bracket outwardly of the medial portion thereof which is connected by bolt 75 to the jack. As illustrated, three bolts 85 pass through both sides of the bracket and each brace although greater or lesser numbers of fasteners may be employed depending upon the capacity of the elevator, the o weight of the car and other relevant factors. As best o Qo 10, seen in Fig. 1, bracket 65 serves to provide a sso connection hbetween the jack and the car frame, and it Swill thus be appreciated that the connections between 04 0P Sbracket 65 and braces 55 are loaded by the weight of 0 0 the car. However, the tubular shape of the braces and the U-shaped cross section of bracket 65 cause each of 0: bolts 85 to be loaded in double shear for enhancing the strength of the connection. Furthermore, it will 0°0 be appreciated that braces 55 are loaded entirely in r tension which enhances the stability of the car and 40 ,J eliminates any need for more massive structural components required to accommodate compressive and/or bending modes of loading.

i Referring again to Fig. i, the side frame assemblies are connected together by a cross head comprising a pair of generally parallel channel members 95 connected by bolts, rivets or the like at opposite ends thereof to inwardly extending plates 100 attached to braces 55 by a welded or similar connections thereto. Channels 95 support oblique brackets 105 and lateral brackets 110 by bolted, riveted or similar connections thereto, brackets 105 -7and 110 being connected together at 115 by bolts, rivets or the like. As illustrated, each lateral bracket 110 carries an upper guide shoe 120 which slideably engages a corresponding guide rail 125 of generally T-shaped cross section which is mounted to a sidewall of the hoistway. Those skilled in the art will, of course, recognize that the engagement of upper guide shoes 120 as well as lower guide shoes 130 CC o t (carried by the car frame at the bottom of the 20S platform thereof) with guide rails 125 provides So additional lateral stability to the car. It will be o C seen that brackets 110 function not only as mounts for the guide shoes but also as mounts for leveling switch o o 135 including rollers 140 operated by stationary cams 145 mounted on the guide rail. Those skilled in the oC. o art will, of course, readily appreciate that leveling switch 135 operated by cam 145 along with leveling switch 150 operated by cam 155 attached to the opposite side frame assembly controls hydraulic fluid flow to and from the jacks for controlling such functions as acceleration and deceleration of the car by the jacks. Bracket 110 in providing a mount for both guide shoe 120 and leveling switch 135 simplifies the overall structure of the car frame by eliminating the need for separate mounts for these components.

Platform 40 comprises a generally planar array of tubular beams including a plurality of parallel beams 160 joined at opposite ends thereof (as by welding or the like) by a pair of generally parallel beams 165 orthogonally disposed with respect to beams 160. The platform includes a floor portion 167 overlying the .8 platform frame and mounted thereto as by screws (not shown) or the like, the floor portion comprises a laminar arrangement of a lightweight, structural upper plate 170 formed from such material as wood, composite, or an oriented strand wood fiber material such as that sold by Weyerhaeuser Company undc-r the mark Structurwood and a metallic lower plate 175 functioning as a fire stop and typically formed from aluminum, sheet steel, or the like. Such a platform structure, employing a planar array of tubular beams and a lightweight floor, substantially reduces the 4 weight of the platform as compared to the platforms of :o prior art elevators thereby reducing the required strength and thus the weight of the remainder of the car frame as well as the hydraulic requirements of the elevator.

I

Referring to Fig. 2, each of jacks 45 comprises a cylinder 200 including a head 205 defined by housing members 207 and 208 and a plunger 210 disposed within 2d the cylinder for reciprocal movement with respect thereto in response to changes in pressurization and draining of the cylinder with hydraulic fluid through hydraulic lines 215. Plunger 210 is mounted on connecting rod 220 which extends outwardly of cylinder 200 through the head, the upper end of rod 220 including a hole through which bolt 75 is threaded for connecting the rod to bracket As set forth hereinabove, in the event of a malfunction of the hydraulic control system it is desirable to provide hydraulic elevators with means to limit overtravel of the car while safely dissipating jack 45 is provided with stop means disposed proximally to the cylinder head for limiting overtravel of the plunger while dissipating the kinetic energy thereof and means associated with the plunger for abutment with the stop means. As best illustrated in Fig. 2, the stop means comprises a hard S impact ring 225 of steel or the like backed by a o 0 resilient urethane ring 230 which is in turn backed by a hard stop ring 235. In the event that plunger 210 o o is caused to overtravel upwardly due to an hydraulic 0 "Qo 5 system malfunction, the plunger will abut impact ring 9 6o 225 which upwardly compresses urethane ring 230 against stop ring 235, thereby eliminating further C plunger overtravel and dissipating the energy of such overtravel by compression of the urethane ring to reduce the risk of damage to the jack. Head 220 also accommodates a rubber seal 240, a wear ring 245 and wiper 250 in the usual manner. It will be noted that since the jack is received interiorly of the oblique braces 55 and since the guide rails are laterally offset from the jack, the jack is readily accessable for ease in maintenance thereof. Moreover, the lack of interference with the jack by the car frame and guide rails allows large clearances for head 205 and thus, the convenient accommodation of the two rectangular housing members 207 and 208 bolted together at the corners thereof with four bolts 255.

This is to be contrasted with various prior art elevator jack designs wherein jack head clearances are AV I -l 10 so limited that the head must be cylindrical in shape and of a diameter requiring bolting with as many as 9 to 12 bolts making such a head costly to manufacture and difficult to service.

Referring again to Fig. 1, as illustrated therein, jacks 45 are disposed adjacent to the car platform at medial locations on opposed sides thereof whereby the car is supported in a generally symmetric t, manner thereby reducing rail reactions to loading oiu thereof and allowing rails of lighter weight than r o those of the past to be used. Disposition of the 0 o jacks interiorly of the car frame side assemblies So (between oblique braces 55) not only renders the jacks 0eo easily serviceable, but provides a more efficient use 0 0 'of the interior of the hoistway.

Guide rails 125 are mounted at the upper portions ao,0 thereof to the hoistway walls with clamps 260 carried by fixtures 265 bolted to the hoistway walls and at the lower ends thereof by fastening (such as by welding) to angle brackets 270 mounted to the floor of the pit by any suitable means such as bolts and the like (not shown). The guide rails and jacks are also fixed to the hoistway walls and aligned with each z •t other by connection to mounting brackets 275 each comprising a plurality of spaced feet 280 at which the bracket is secured to the hoistway sidewalls as by bolting. As shown, the bracket is a unitary structure in which the feet 280 alternate with fixture portions (lands) 285 and 290 at which jack and guide rail, respectively, are connected to the bracket as by clamping. Since the car is symmetrically supported by 11 the jacks, the jacks are generally symmetrically loaded and therefore, the prior art practice of burying the lower ends of the jacks to accommodate bending loads thereon is unnecessary. Accordingly, the lower ends or bases of the jacks are received within a jack base comprising an upperwardly open, generally U-shaped channel member 295 closed at the ends thereof with closure plates 300 fastened thereto roO such as by welding, the closure plates being apertured to receive the jack bases for the alignment and o vertically unrestrained accommodation thereof within the channel member. Such vertically, unrestrained accommodation allows the jacks to freely "jump" "RO upwardly in the event of overtravel of the car for further dissipation of the kinetic energy associated therewith. The jack base also provides a convenient o 9o mount for receptacles 305 which accommodate buffer ooo springs 309' on which the platform may rest when lowered. The receptacles are fixed to the web of the channel member by any suitable means such as bolts or the like.

Referring to Figs. 5 and 6, an alternate embodi- 4 1 Ott% ment of the elevator is shown. In this embodiment the lower portions of guide rails 125 have been eliminated, the jack cylinders taking the place of the lower rail portions and the lower slotted guide shoes have been replaced by a guide shoe 302 *comprising a Ushaped bracket 305 carrying rollers 310 at the ends thereof. Bracket 305 is bolted at 315 to a mounting member 320 at the bottom of the car platform in alignment with jack cylinders 200 so that rollers 310 a i 12 engage the cylinder walls. Thus, with this arrangement, enhanced multi-diminsional lateral stability of the car at lower positions thereof is attained by movement of the car along the jack cylinders without necessitating lower guide rails, thereby further simplifying the elevator and rendering the elevator more economical in both material and assembly costs thereof.

As illustrated, rollers 310 bear against those portions of the lateral surfaces of the jack cylinders adjacent the car, and are angularly offset approximately from one another with respect to the longitudinal axis 010 of a corresponding jack. Thus, it is seen that the car is stabilized in both front-to-back and side-to-side 8o 6 o. directions with only two rollers on each side of the car.

Since no roller is required directly between the car and 0 a S0 jack cylinders, the sidewalls of the car may be disposed 0 0 in very close proximity to the jack cylinders for optimum car width and/or enhanced compactness. It will be appreciated that while the roller offset of approximately o 90° is shown, an offset of from approximately 600 to O approximately 1200 may be employed with equal utility.

Referring to figures 7-9, two alternate embodiments of the roller configurations are shown. In figure 7, a guide shoe 325 mounted on the floor of the car by bracket 330, carries a pair of vertically spaced, generally U-shaped brackets 335, each being attached to the guide shoe by screws 337 and carrying a set of rollers 340 at the ends thereof. Vertically spacing the roller sets in the manner illustrated in figure 7, further enhances lateral stability by minimizing any tendency of the car to rock laterally back and forth and may even render upper guide rails 125 and the corresponding guide shoes, unnecessary. Furthermore, a greater number of rollers enhances the distribution of lateral loads over the rollers and allows the rollers to be of a smalle- 13 diameter, thereby further enhancing the compactness of the elevator (reducing the required free space between car and rails) while allowing for greater car width. While a generally 900 roller offset (with respect to the longitudinal jack axes) is illustrated, an offset of from to 1200 may be employed.

In figures 8 and 9, lateral car stability is. still further enhanced by laterally restraining the car in three directions with two sets of three rollers each. As shown, guide shoe 345 is provided with a pair of vertically spaced brackets 350, each carrying a set of three rollers 0 0 355, one of the rollers in each set being disposed between the car and the jack cylinder for stabilizing the car in a S side-to-side direction and the remaining two rollers S9 o bearing against the front and rear of the jack surface for a stabilizing the car in a front-to-back direction. Of course, it will be appreciated that the embodiment illustrated in figures 8 and 9 exhibits the same enhanced o.0 compactness and lateral load distribution as the alternate embodiment described hereinabove and may also render the upper guide rails unnecessary.

00a0 o 0 From the foregoing, it will be seen then that the car frame described herein is simpler than prior art frames since it requires neither adjustable rods nor upright members. The frame is more stable than prior art frames since the side supports are loaded in tension, without any significant compressive or bending loads thereon and the joints are rigid. Since the jacks are generally coplanar with the side frame assemblies, the elevator is compact and the jacks are easily serviceable. The tubular frame floor further contributes to the lightness of the elevator and the symmetric support of the car frame by the centrally disposed jacks allows the use of smaller rails, due to minimal rail reactions. The symmetric loading of the jacks also eliminates the need to bury the lower ends -14of the jacks thus eliminating the risk of the galvanic corrosion of the jack ends due to such burial.

Furthermore, since the jacks do not require burying, they may rest on the pit floor in a vertically unrestrained orientation allowing the entire elevator to "jump" in the event of car overtravel thereby contributing with the novel jack head structure to the elevator's ability to dissipate the kinetic energy associated with upward overtravel of the car. The integral guide shoe and levelling switch mounting, the one piece rail jack bracket and the jack base further simplify the manufacture and S-g erection of the elevator.

It should be understood that the invention is not limited to the particular embodiments shown and described 0 herein, but that various changes and modifications may be o o. made without departing from the spirit and scope of the o" invention as defined by the following claims.

0 0 04

CO

Claims (4)

1. An elevator comprising a car powered by at least one hydraulic jack disposed adjacent to said car, said hydraulic jack including a cylinder and a plunger disposed therewithin for reciprocal movement with respect thereto, wherein: a guide shoe is disposed on said car, said guide shoe carrying at least one set of rollers having vertically spaced axes of rotation, said rollers bearing against the lateral surface of said jack cylinder for imparting 11,0, enhanced stability, compactness and lateral load distribution to said elevator without necessitating a S guide rail distinct from said jack cylinder. oq So

2. An elevator as claimed in Claim 1 wherein said guide "o shoe carries a plurality of said roller sets angularly S offset from one another for the multidimensional impartation of said enhanced stability, compactness and load distribution to said elevator. 0

3. An elevator as claimed in Claim 2 wherein a single a a 0 pair of said roller sets engages that portion of said lateral surface of said jack cylinder adjacent said o o elevator car and being angularly offset from approximately 600, to approximately 1200 from one another with respect to the longitudinal axis of said jack cylinder, whereby said enhanced multidimensional stability is achieved with still further enhanced compactness and a minimum number of rollers.

4. An elevator as claimed in Claim 2 wherein three of said roller sets engage that portion of said lateral surface of said jack cylinder adjacent said elevator car each roller set being angularly offset approximately 900 from an adjacent set with respect to the longitudinal axis of said jack cylinder. -i i i- i 'L 16 An elevator substantially as herein before described with reference to the accompanying figures. DATED this 20th day of September, 1988 OTIS ELEVATOR COMPANY Attorney: LEON K. ALLEN Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS PT CF I i It it t f l o t Ii 0 t I I o t 605 II i I et't II ti I I