CA1243295A - Polyethylene sheaves for rope-drawn transportation system - Google Patents
Polyethylene sheaves for rope-drawn transportation systemInfo
- Publication number
- CA1243295A CA1243295A CA000505124A CA505124A CA1243295A CA 1243295 A CA1243295 A CA 1243295A CA 000505124 A CA000505124 A CA 000505124A CA 505124 A CA505124 A CA 505124A CA 1243295 A CA1243295 A CA 1243295A
- Authority
- CA
- Canada
- Prior art keywords
- sheave
- cable
- groove
- sheaves
- uhmwpe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
- F16H55/32—Friction members
- F16H55/36—Pulleys
- F16H55/48—Pulleys manufactured exclusively or in part of non-metallic material, e.g. plastics
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Pulleys (AREA)
- Ropes Or Cables (AREA)
Abstract
Polyethylene Sheaves for Rope-Drawn Transportation System Abstract A sheave for cooperating with a cable is made from ultra-high-molecular-weight polyethylene (UHMWPE). The groove angle is selected according to the coefficient of friction of the UHMWPE so as to prevent the cable from climbing out of the sheave groove. The low coefficient of friction of UHMWPE
makes possible a very shallow groove.
makes possible a very shallow groove.
Description
1;~43Z9~;
Description Polyethylene Sheaves for Rope-Drawn Transportation System Technical Field of the Invention The invention relates to pul~leys, or sheaves that cooperate with cables, such as in funicular-type transportation sys~tems.
.
Background of the Invention Transportation systems àre known in~which a vehicle is drawn by a cable. For runs of appreciable length, the cable must be~supported every thirty meters, or so, by grooved sheaves. Due to the twist of the cable, and the tension thereon, there is a tendency for the cable to climb out of the sheave groove.
Steel sheaves are the norm. They are inexpensive and durable,~and their smooth hard surface reduces the tendency for the cable to climb out of the groove. However, they impart a significant amount of wear to the cable. Rubber, or rubber-lined steel sheaves are expensive and less durable than their steel counterparts, but they are much easier on the cable.
Disclosure of the Invention ThereEore, it is an object of this invention to provide a sheave that is both inexpensive and durable, and that tends to keep the cable in the groove without wearing on the cable.
, . . .
r~
`~'~
.
~L24;~9S
According to the invention, sheaves are fabricated from ultra-high-molecular-weight polyethylene (UHMWPE) and the groove angle is minimized according to the coefficient of friction of the UHMWPE.
Other objects, features and advantages of the invention will become more apparent in light of the following description thereof.
Brief Description of the Drawings Fig. 1 is a perspective view showing the sheaves of this invention in use in a cable-drawn transportation system; and Fig. 2 is an edge-on view of a sheave, typical of the sheaves in Fig. 1.
Detailed Description of the Invention Fig. 1 shows a transportation system wherein a car 10 is attached to a cable 12 and moved thereby along a smooth track 14. ~The car rides on a cushion of air as provided by hoverpads 16. Sheaves 18, disposed every thirty meters, or so, along the track accommodate cable sag. The transportation system of Fig. 1 is representative of the OTIS SHUTTLE.
FigO 2 shows a sheave 18 which is essen~ially a disc having two sides 20, 22 and a circumferential edge 24. The edge 24 is not flat, but is formed to cooperate with the cable 12. Since the sheave must turn in response to cable motion, it is attached via a suitable axle 26 journaled to suitable support means 28 on the track.
rRko~
~.2432~5 The outer edge 24 of the sheave is generally V-shaped, concave towards the center of the sheave, and forms an angle A with respect to an imaginary surface 28, which represents the side of a squat cylindrical disc from which the sheave may be machined. The groove 24 is symmetrical from side-to-side, forming two ears 30 and 32. At the apex of the groove it abruptly becomes appro~imately quarter-circular in a region 34, with a radius corresponding to the radius of the cable 12.
In the Otis Shuttle, cable tensions of 45,000 Newtons and velocities of 10 meters per second are common. Furthermore, the track does not always follow a straight and level course. Although the sheaves may be inclined to provide both lateral and vertical suport to the cable in inclines and curves~
the cable will still try to climb out of the sheave.
The coefficient of friction of the sheave and the angle of the groove are key factors in maintaining the cable in t`he groove. The higher the coefficent of friction, thè~easier it is for the cable to climb out of the groove. The shallower the groove, the easier it is for the cable to climb out of the groove. Therefore, on the one hand, it is necessary to make the sheave groove as deep as possible. However, on the other hand, the deeper the groove, the flimsier the ears 30, 32 will become for a sheave of a given size. There is no analogous limit to reducing the coefficient of friction.
Simply stated, the slipperier the groove, the better.
- ~z43~95 The invention resides in the use of an ultra-high-molecular-weight polyethylene (UHMWPE), such as HOSTALEN ~ GUR, for the sheave material, in the selection of~a groove angle based on sheave material, and in the unexpected advantages of this unique combination of features as applied to a cable-drawn vehicle. HOSTALEN ~ GUR is available from American Hoechst Corporation, Plastics Division, 289 North Main Street, Leominster, Massachusetts 01453, and is described in detail in Desi~ning with the toughest of all plastics, Plastics Design Forum, May/June 1978.
As applied to the sheave of this invention, UHMWPE exhibits outstanding features. It is extraordinarily tough, yet its paraffin-like surface resists cable abrasion and is easy on the cable. It is easily machined, and has a low coefficient of friction. Concerning the latter, the inventor has selected a sheave groove angle that is related to the coefficient of frictio~ to minimize the tendency for the cable to climb out~of the groove.
The coefficient of friction for HOSTALEN ~ GUR
is approximately 0.1. Therefore the slope, or tangent, of the groove must also be at least 0.1 to give a critical sheave groove angle "A" of approximately 6 degrees. A safety factor of 4 would dictate a groove angle of about 25 degrees.
As stated hereinbefore, the disadvantage of increasing the groove angle is weakening the groove ears. With UHMWPE, a much lower groove angle can be employed which results in a stronger, smaller sheave.
~ ~LZ~3;;~95i It should be understood that the invention has been described with respect to a particular embodiment thereof, and that various additions and changes can be made thereto without departing from the spirit and scope of the invention.
What is claimed is:
Description Polyethylene Sheaves for Rope-Drawn Transportation System Technical Field of the Invention The invention relates to pul~leys, or sheaves that cooperate with cables, such as in funicular-type transportation sys~tems.
.
Background of the Invention Transportation systems àre known in~which a vehicle is drawn by a cable. For runs of appreciable length, the cable must be~supported every thirty meters, or so, by grooved sheaves. Due to the twist of the cable, and the tension thereon, there is a tendency for the cable to climb out of the sheave groove.
Steel sheaves are the norm. They are inexpensive and durable,~and their smooth hard surface reduces the tendency for the cable to climb out of the groove. However, they impart a significant amount of wear to the cable. Rubber, or rubber-lined steel sheaves are expensive and less durable than their steel counterparts, but they are much easier on the cable.
Disclosure of the Invention ThereEore, it is an object of this invention to provide a sheave that is both inexpensive and durable, and that tends to keep the cable in the groove without wearing on the cable.
, . . .
r~
`~'~
.
~L24;~9S
According to the invention, sheaves are fabricated from ultra-high-molecular-weight polyethylene (UHMWPE) and the groove angle is minimized according to the coefficient of friction of the UHMWPE.
Other objects, features and advantages of the invention will become more apparent in light of the following description thereof.
Brief Description of the Drawings Fig. 1 is a perspective view showing the sheaves of this invention in use in a cable-drawn transportation system; and Fig. 2 is an edge-on view of a sheave, typical of the sheaves in Fig. 1.
Detailed Description of the Invention Fig. 1 shows a transportation system wherein a car 10 is attached to a cable 12 and moved thereby along a smooth track 14. ~The car rides on a cushion of air as provided by hoverpads 16. Sheaves 18, disposed every thirty meters, or so, along the track accommodate cable sag. The transportation system of Fig. 1 is representative of the OTIS SHUTTLE.
FigO 2 shows a sheave 18 which is essen~ially a disc having two sides 20, 22 and a circumferential edge 24. The edge 24 is not flat, but is formed to cooperate with the cable 12. Since the sheave must turn in response to cable motion, it is attached via a suitable axle 26 journaled to suitable support means 28 on the track.
rRko~
~.2432~5 The outer edge 24 of the sheave is generally V-shaped, concave towards the center of the sheave, and forms an angle A with respect to an imaginary surface 28, which represents the side of a squat cylindrical disc from which the sheave may be machined. The groove 24 is symmetrical from side-to-side, forming two ears 30 and 32. At the apex of the groove it abruptly becomes appro~imately quarter-circular in a region 34, with a radius corresponding to the radius of the cable 12.
In the Otis Shuttle, cable tensions of 45,000 Newtons and velocities of 10 meters per second are common. Furthermore, the track does not always follow a straight and level course. Although the sheaves may be inclined to provide both lateral and vertical suport to the cable in inclines and curves~
the cable will still try to climb out of the sheave.
The coefficient of friction of the sheave and the angle of the groove are key factors in maintaining the cable in t`he groove. The higher the coefficent of friction, thè~easier it is for the cable to climb out of the groove. The shallower the groove, the easier it is for the cable to climb out of the groove. Therefore, on the one hand, it is necessary to make the sheave groove as deep as possible. However, on the other hand, the deeper the groove, the flimsier the ears 30, 32 will become for a sheave of a given size. There is no analogous limit to reducing the coefficient of friction.
Simply stated, the slipperier the groove, the better.
- ~z43~95 The invention resides in the use of an ultra-high-molecular-weight polyethylene (UHMWPE), such as HOSTALEN ~ GUR, for the sheave material, in the selection of~a groove angle based on sheave material, and in the unexpected advantages of this unique combination of features as applied to a cable-drawn vehicle. HOSTALEN ~ GUR is available from American Hoechst Corporation, Plastics Division, 289 North Main Street, Leominster, Massachusetts 01453, and is described in detail in Desi~ning with the toughest of all plastics, Plastics Design Forum, May/June 1978.
As applied to the sheave of this invention, UHMWPE exhibits outstanding features. It is extraordinarily tough, yet its paraffin-like surface resists cable abrasion and is easy on the cable. It is easily machined, and has a low coefficient of friction. Concerning the latter, the inventor has selected a sheave groove angle that is related to the coefficient of frictio~ to minimize the tendency for the cable to climb out~of the groove.
The coefficient of friction for HOSTALEN ~ GUR
is approximately 0.1. Therefore the slope, or tangent, of the groove must also be at least 0.1 to give a critical sheave groove angle "A" of approximately 6 degrees. A safety factor of 4 would dictate a groove angle of about 25 degrees.
As stated hereinbefore, the disadvantage of increasing the groove angle is weakening the groove ears. With UHMWPE, a much lower groove angle can be employed which results in a stronger, smaller sheave.
~ ~LZ~3;;~95i It should be understood that the invention has been described with respect to a particular embodiment thereof, and that various additions and changes can be made thereto without departing from the spirit and scope of the invention.
What is claimed is:
Claims (5)
1. A sheave for supporting a moving cable under tension, characterized in that said sheave is made from ultra-high-molecular-weight polyethylene (UHMWPE).
2. A sheave according to claim 1 wherein the sheave has an angled groove disposed about its circumference for receiving the moving cable, and the angle of the groove is selected according to the coefficient of friction of the UHMWPE.
3. A sheave according to claim 2 wherein the coefficient of friction for the UHMWPE is approximately 0.1 and the groove angle is at least approximately 6 degrees.
4. A sheave according to claim 3 wherein the groove angle is approximately 25 degrees.
5. A transportation system comprising a cable-drawn vehicle wherein the cable is supported by sheaves as described in claim 1.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US72358385A | 1985-04-15 | 1985-04-15 | |
| US723,583 | 1985-04-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1243295A true CA1243295A (en) | 1988-10-18 |
Family
ID=24906862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000505124A Expired CA1243295A (en) | 1985-04-15 | 1986-03-26 | Polyethylene sheaves for rope-drawn transportation system |
Country Status (6)
| Country | Link |
|---|---|
| AU (1) | AU582839B2 (en) |
| CA (1) | CA1243295A (en) |
| DE (1) | DE3611258A1 (en) |
| FR (1) | FR2582372A1 (en) |
| GB (1) | GB2174173A (en) |
| ZA (1) | ZA862007B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9701517B2 (en) | 2012-05-04 | 2017-07-11 | Otis Elevator Company | Methods and apparatuses for applying a substrate onto an elevator sheave |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4683863B2 (en) * | 2003-06-19 | 2011-05-18 | インベンテイオ・アクテイエンゲゼルシヤフト | Elevator for load transportation by movable traction means |
| CN105173970B (en) * | 2015-09-29 | 2017-11-28 | 上海化工研究院有限公司 | A kind of ultra-high molecular weight polyethylene elevator sliding guide shoe shoe guide and preparation method thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE513947C (en) * | 1929-04-08 | 1930-12-06 | Adolf Bleichert & Co A G | Drive roller for cable cars |
| DE1906054U (en) * | 1964-05-19 | 1964-12-10 | Tefabag Maschinen Und Seilbahn | CABLEWAY IMPACTOR. |
| DE1900707B2 (en) * | 1969-01-08 | 1973-07-05 | PROCESS AND BULK FOR MANUFACTURING ROPE ROLLS | |
| US4034616A (en) * | 1975-10-16 | 1977-07-12 | Rauscher David A | Pulley means |
| FR2525981B1 (en) * | 1982-04-28 | 1985-06-07 | Creissels Denis | CABLE WITH TWO TRACTOR CARRIER CABLES |
-
1986
- 1986-03-18 ZA ZA862007A patent/ZA862007B/en unknown
- 1986-03-26 CA CA000505124A patent/CA1243295A/en not_active Expired
- 1986-03-26 AU AU55283/86A patent/AU582839B2/en not_active Ceased
- 1986-04-03 FR FR8604752A patent/FR2582372A1/en active Pending
- 1986-04-04 DE DE19863611258 patent/DE3611258A1/en not_active Withdrawn
- 1986-04-15 GB GB08609183A patent/GB2174173A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9701517B2 (en) | 2012-05-04 | 2017-07-11 | Otis Elevator Company | Methods and apparatuses for applying a substrate onto an elevator sheave |
| US10647547B2 (en) | 2012-05-04 | 2020-05-12 | Otis Elevator Company | Methods and apparatuses for applying a substrate onto an elevator sheave |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8609183D0 (en) | 1986-05-21 |
| AU582839B2 (en) | 1989-04-13 |
| DE3611258A1 (en) | 1986-10-23 |
| GB2174173A (en) | 1986-10-29 |
| FR2582372A1 (en) | 1986-11-28 |
| ZA862007B (en) | 1987-03-25 |
| AU5528386A (en) | 1986-10-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100716101B1 (en) | Improved sheave design | |
| JP2807037B2 (en) | Sliding shoe for slide roof, slide tilt roof, etc. | |
| GB2206220B (en) | Optical fibre cables | |
| CA2109760A1 (en) | Seat Slide Device | |
| AU693542B2 (en) | Elevator machinery and its installation | |
| CA2257755A1 (en) | Fiber optic cable capable metal raceway system | |
| CA1243295A (en) | Polyethylene sheaves for rope-drawn transportation system | |
| FR2715006B1 (en) | Transport installation with two overhead cables. | |
| FR2640272B1 (en) | POLYMERIC COMPOUNDS RESULTING FROM THE CONDENSATION OF AN ALKYLENE POLYAMINE ON A COPOLYMER HAVING VICINAL CARBOXYL GROUPS AND THEIR USE AS ADDITIVES TO LUBRICANTS | |
| HK1011716A1 (en) | Polymers having enhanced hydrophilicity and thermal regulated properties and process of producing the same | |
| MY113721A (en) | Optical fiber cable | |
| GB2218637B (en) | Dressings | |
| DE59602317D1 (en) | Mechanical rope derailment protection | |
| EP0436191B1 (en) | Flexible escalator handrail | |
| EP0131929A3 (en) | Safety helmet for motor cyclists or the like | |
| EP0240936A3 (en) | V belt | |
| CA2193162A1 (en) | Cable bight wear guard assembly | |
| ES2016960B3 (en) | HYDROCYCLON OR HYDROCYCLONE PARTS, AS WELL AS THE PROCEDURE FOR THE MANUFACTURE | |
| DE3364883D1 (en) | Tablecloth underlay | |
| PL183310B1 (en) | Assembly of rollers for a closed-loop cableway | |
| Kennedy Jr et al. | Wear of polyethylene in small-amplitude oscillatory motion | |
| JPS58214047A (en) | V-belt | |
| CA2099265A1 (en) | Runner for air conveyor system | |
| DE69300336D1 (en) | Cable car with cables deflected to the side. | |
| IT1255386B (en) | Simple or composite elemental damping system in a "C" or linear assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |