CA1149373A - Cable take-up and pay-out device for tow-lift cables - Google Patents
Cable take-up and pay-out device for tow-lift cablesInfo
- Publication number
- CA1149373A CA1149373A CA000369995A CA369995A CA1149373A CA 1149373 A CA1149373 A CA 1149373A CA 000369995 A CA000369995 A CA 000369995A CA 369995 A CA369995 A CA 369995A CA 1149373 A CA1149373 A CA 1149373A
- Authority
- CA
- Canada
- Prior art keywords
- brake shoe
- axis
- tow
- brake
- braking
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61B—RAILWAY SYSTEMS; EQUIPMENT THEREFOR NOT OTHERWISE PROVIDED FOR
- B61B11/00—Ski lift, sleigh lift or like trackless systems with guided towing cables only
- B61B11/004—Means connecting load and cable
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H75/00—Storing webs, tapes, or filamentary material, e.g. on reels
- B65H75/02—Cores, formers, supports, or holders for coiled, wound, or folded material, e.g. reels, spindles, bobbins, cop tubes, cans, mandrels or chucks
- B65H75/34—Cores, formers, supports, or holders for coiled, wound, or folded material, e.g. reels, spindles, bobbins, cop tubes, cans, mandrels or chucks specially adapted or mounted for storing and repeatedly paying-out and re-storing lengths of material provided for particular purposes, e.g. anchored hoses, power cables
- B65H75/38—Cores, formers, supports, or holders for coiled, wound, or folded material, e.g. reels, spindles, bobbins, cop tubes, cans, mandrels or chucks specially adapted or mounted for storing and repeatedly paying-out and re-storing lengths of material provided for particular purposes, e.g. anchored hoses, power cables involving the use of a core or former internal to, and supporting, a stored package of material
- B65H75/44—Constructional details
- B65H75/4436—Arrangements for yieldably braking the reel or the material for moderating speed of winding or unwinding
- B65H75/4442—Arrangements for yieldably braking the reel or the material for moderating speed of winding or unwinding acting on the reel
- B65H75/4447—Arrangements for yieldably braking the reel or the material for moderating speed of winding or unwinding acting on the reel centrifugally
-
- 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
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D2129/00—Type of operation source for auxiliary mechanisms
- F16D2129/04—Mechanical
- F16D2129/043—Weights
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Braking Arrangements (AREA)
- Emergency Lowering Means (AREA)
- Unwinding Of Filamentary Materials (AREA)
- Storing, Repeated Paying-Out, And Re-Storing Of Elongated Articles (AREA)
- Extraction Or Liquid Replacement (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Epoxy Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A take-up and pay-out device for tow cables of tow lifts having a return spring for the tow cable wound onto a tow cable drum and a centrifugal brake that has at least one centrifugal weight for the tow cable drum. In that area closest to the axis the centrifugal weight has a braking surface that extends in the manner of a cam, this engaging the inside wall of the housing when the tow cable is paid out, whereas a rotatable brake shoe is arranged in that area of the centrifugal weight furthest from the axis, this moving into the operating position, i.e., in contact with the inside wall of the housing, automatically when the tow cable is taken up and simultaneously the cam-like and projecting braking surface, simultaneously lifting the inside wall of the housing. Thus, when the tow cable is paid out there is a powerful braking effect, and when the tow cable is taken up there is a somewhat less braking effect on the part of the centrifugal brake.
A take-up and pay-out device for tow cables of tow lifts having a return spring for the tow cable wound onto a tow cable drum and a centrifugal brake that has at least one centrifugal weight for the tow cable drum. In that area closest to the axis the centrifugal weight has a braking surface that extends in the manner of a cam, this engaging the inside wall of the housing when the tow cable is paid out, whereas a rotatable brake shoe is arranged in that area of the centrifugal weight furthest from the axis, this moving into the operating position, i.e., in contact with the inside wall of the housing, automatically when the tow cable is taken up and simultaneously the cam-like and projecting braking surface, simultaneously lifting the inside wall of the housing. Thus, when the tow cable is paid out there is a powerful braking effect, and when the tow cable is taken up there is a somewhat less braking effect on the part of the centrifugal brake.
Description
The present invention relates to a take-up and pay-out device for the tow cables of tow lifts having a return spring for the tow cable that is wound onto a tow cable drum and a centrifugal brake for the tow cable drum, this brake having at least one centrifugal weight, in connection with which the distance between the axis of rotation of the centrifugal weight and the point of application of the centrifugal weight on an interior wall of the housing of the take-up and pay-out device, that is preferably provided with a brake lining, is automatically variable according to the direction of rotation of the tow cable drum,such that when the tow cable is being paid out the point of application of the centrifugal weight is closer to the rotational axis of the centrifugal weight than when the tow cable is being taken up.
In a known device based on this principle, a brake - shoe that is rotatably mounted about an axis parallel to the axis of rotation of the centrifugal weight is arranged between two stops, this brake shoe having two braking surfaces that are nclined towards each other and which extend beyond the outer edge of the centrifugal weight (see Swiss Patent No. 502,214).
However, this device has the main disadvantage that when the tow cable is being taken up and paid out there are only insignificant differences with respect to the point of application of the rotatable brake shoe on the brake lining bonded to the inside wall of the housing and accordingly the resulting differences in the braking effect are far too small.
In another device based on the above principle, it is true that the requirement that there be a higher braking moment when the tow cable is being paid out than when the tow cahle is being taken up can be better satisfied. However, this device has the disadvantage that in order to vary the lever arm of the centrifugal weight the axis of the centrifugal weight is ;373 guided in a slot (see Swiss Patent No. 348,176). Compared to a fixed axis of rotation this does not provide a sufficiently secure mounting for the centrifugal weight about its axis of rotation, so that the centrifugal weight can tilt and topple, this being prejudicial to the desired function.
The present invention thus provides a take-up and pay-out device for tow cables of tow lifts in accordance with the aforesaid principle by which a sufficiently large difference in the braking effect during pay-out of t,he cable vis-a-vis the taking up of the cable is ensured without the stable position-ing of the centrifugal weight being in any way impaired.
According to the present invention there is provided a tow rope pull-out and retracting device, comprising a housing havin~aninternalsurface,areeldisposedwithinsaidhousingfortakin~up and payingout atowrope,a retracting spring coupledtosaidreel,at least one flyweight pivotally mounted on said reel about a first axis, said flyweight having a protruding braking surface near said axis adapted to engage said internal surface in one direction of rotation and a brake shoe pivotally mounted about a second axis, remote from said first axis, and adapted to engage said inter-nal surface in an opposite direction of rotation, whereby a dif-ferent braking force is produced in opposite senses of rotation.
Thus according to the present invention, an area fur-thest from the axis the centrifugal weight has a brake shoe that is rotatably mounted about an axis, parallel to the axis of ~1~93~3 rotation of the centrifugal weight, between two stops that are provided and which, in that area close to the axis, has a braking surface that extends preferably in the manner of a cam.
Using the device according to the invention it is possible to obtain a considerable difference in braking performance when the cable is being taken up, on the one hand, and when the tow cable is being paid out on the other, because the braking surface that protrudes preferably like a cam that is effective when the tow cable is being paid out and the braking shoe that is in its operating position when the tow cable is being taken up are located a relatively grea, distance from each other. In addition, the device according to the present invention has good stability because in that place where the loading is particularly great, namely, in the area of the centrifugal weight that is close to the axis a stable braking surface preferably in the form of a cam-like projection is formed, this contributing to the direct transfer of force to the axis of the centrifugal weight. The rotatable brake shoe is located in the area furthest from the axis, that is to say, where the loading is significantly less. Thus neither the brake shoe nor its mountlng are subjected to excessive loads.
The present invention will be further described by way of the accompanying drawings, in which:-Fig. 1 is a cross-section through the axis of the cable drum according to I-I of Fig. 2 of a pay-out and take-up devlce according to one embodiment of the present invention;
Fig. 2 is a cross section in the line II-II of the device of Fig. 1 with the centrifugal weight being in the position for paying out the tow cable;
Fig. 3 is a similar cross-section to Fig. 2 when the tow cable is being taken up;
Fig. 4 is an enlarged cross section on the line IV-IV
of Fig. 3;
Fig. 5 is a vertical cross section on the line V-V
of Fig. 6;
Fig. 6 is a cross section on the line VI-VI of Fig. 5 with the centrifugal weight being in the position adopted when the tow cable is being paid out;
Fig. 7 is a similar section to Fig. 6 of a further embodiment of the device of the present invention when the tow cable is being taken up;
Fig. 8 is a vertical section on the line VIII-VIII
of Figs. 9 and lO;
Fig. 9 is a cross section on the line IX-IX of Fig. 8, with the centrifugal weight in the position for paying out the cable;
Fig. 10 is a similar cross section when the tow cable is being taken up, in a further embodiment of the device of the present invention;
Fig. ll is a vertical section through the axis of the cable drum;
~ig. 12 is a normal section of a variation for Figs.
8 - 10; and I Fig. 13 is a normal section of a variation for the cam-like braking surface of the centrifugal weight.
The take-up and pay-out device according to Figs. 1 - 4 comprises a housing 1, connected through the clamping bracket 2 and the suspension column (not shown) to the circulating device.
The housiny l is extended laterally by the spring housing 3, this containing the return spring 4. The spring 4, in the form of a coil spring, is secured at one end to the housing 3 and at the other to a coiling stud mounted on the shaft 5, this being connected through a coupling to the cable drum 6 for the tow cable. Two studs 8, 9, arranged on the cable drum 6, carry ~9373 the two centrifugal weights 10, 11. A brake lining 12 is on the inside wall of the housing 1. In the areas closest to the axis the centrifugal weights 10, 11 each have a braking surface 24 that extends in the manner of a cam. In the areas furthest from the axis each centrifugal weight 10, 11 has a brake shoe 25 mounted about an axis 26 parallel to the axes 8, 9 of the centrifugal weights, between two stops 27, 28. When the tow cable 7 is paid out in the direction indicated by the arrow 17 (Fig. 2) the cable drum 6 together with the centrifugal weights 10 and 11 rotates in the direction indicated by the arrow 18.
The braking surfaces 24 thereupon come into contact with the brake lining 12. The level-like brake shoes 25 lie against the stops 27 and are inoperative. Because of the proximity of the studs 8 and 9 of the centrifugal weights 10 and 11, respectively, the brake surfaces are pressed extremely hard against the brake lining 12. This results in an extremely high braking moment when the tow cable 7 is paid out. This in its turn results in a very smooth acceleration of the skier as he or she starts off.
When the tow cable 7 is taken up with the empty tow stirrup the cable drum 6 together with the centrifugal weights 10, 11 rotates in the direction of the arrow 19 (Fig. 3). The brake shoes 25 contact the stops 28 and their braking surfaces are pressed against the brake lining 12 whereas the braking surfaces 24 of the centrifugal weights 10, 11 that are close to the axis are lifted away from the brake lining. The force with which the brake shoes 25 press against the brake lining is relatively slight. For this reason the braking moment is also slight, and this results in a rapid but easily slowed taking-up of the tow cable. In the embodiment according to Figs. 5 - 7, the housing 1 of the take-up and pay-out device has a drum-like extens'~on 35, this forming a part of the inner wall of the housing and having a brake lining 36. As in the case of the embodiment according to Figs. 1 - 4 there is a braking surface 24 that extends in the manner of a cam provided on the centrifugal weights 10, 11 in that area of the said weights nearest to the axle, but which, in this case, is now opposite the drum-like extension 35 of the inside of the housing. In the same manner as in the embodiment according to Figs. 1 - 4 in that area furthest from the axes there is on each centrifugal weight a brake shoe 25, that is rotatably mounted about an axis 26 parallel to the centrifugal weight axes 8 and 9. When the tow cable is paid out in the direction of the arrow 17 and the cable drum 6 together with centrifugal weights 10 and 11 rotates in the direction of the arrow 18 the braking surfaces 24 are pressed extremely hard against the brake lining 36. This results in a great braking moment when the tow cable is paid out. The brake shoes 25 then abut against the stops 27 and are inoperative. When the tow cable 7 is taken up the cable drum and the centrifugal weights 10, 11 rotate in the direction of the arrow 19. The brake shoes 25 now lie against the stops 28 and are pressed somewhat less strongly against the brake lining 12. The result of this is a smaller braking moment when the tow cable is taken up. The effect of the high braking moment when the cable is paid out and the smaller braking moment when the tow cable is taken up can be increased if the brake lining 36 has a nigher coefficient of friction than the brake lining 12.
For all practical purposes the embodiment of the device according to Fig. 8 - 10 differs from the embodiment according to Figs. 1 - 4 only in the formation of the rotatable brake shoes 25 in the form of wire stirrups of steel wire. Thus the brake shoes 25 can be produced in a particularly economical manner and, in addition, can be mounted in a very simple manner ~ ~ ~9373 on the centrifugal weights 10, 11, respectively. In this respect, all that is required is a simple hole in the centrifugal weight 10, 11, respectively, into which one arm of the wire stirrup is inserted as an axle 26.
In the embodiment of the device according to Figs. 8 and 10 there are once again stirrup-like rotatable brake shoes in the area of the centrifugal weights 10, 11, furthest from the axis, these lying between two stops 27 and 28, whereas in the area of the centrifugal weights 10 and 11 adjacent the axis there is in each case a brake surface 24 that extends in the manner of a cam. The function of the take-up and pay-out device àccording to Figs. 8 and 10 is the same as in the embodiment of the device according to Figs. 1 - 4.
The effect of the considerably greater braking moment of the centrifugal brake when the tow cable 7 is taken up in comparison with the braking moment when the tow cable 7 is paid out can in all embodiments of the device be increased, e.g., by the fact that the cam-like braking surface 24 has a higher coefficient of friction than the braking surface of the rotatable brake shoe 25. This is the case if the centrifugal - weights 10, 11 are of grey cast iron, and brake surfaces 24 that extend in the manner of a cam are also of grey cast iron, whereas the rotatable brake shoes 25 or their braking surfaces, respectively, are of steel, because grey cast iron has a greater coefflcient of friction than steel. This effect can be increased even further by coating the braking surfaces of the rotatable brake shoes 25, for example, with plastic, or by forming the rotatable brake shoes 25 themselves or plastic.
In the case of the stirrup-like brake shoes 25 according to Figs. 8 - 10, the provislon of a bearing sleeve on the arm of the stirrup-like brake shoe that works with the inside wall of the housing 1 or a brake lining 12 applied thereto, 3~73 respectively, when the tow cable 7 is taken up, is also possible.
In the embodiments illustrated, the stops 27, 28 to limit the movement of the brake shoe 25 are formed on the centrifugal weights 10, 11, themselves. However, there is an equivalent solution in the fact that at least one of the two stops, particularly the stop 28, can be formed on the cable drum 6. On the basis of a variation of the embodiment according to Figs. 8 and 10, Figs. 11 and 12 show the arrangement of both stops 27, 28 for the rotatable brake shoes 25 on the cable drum 6.
The braking surface 24 that is close to the axis does not necessarily have to be formed by a cam of the centrifugal weight 10, 11, respectively, that is limited on both sides by step-like notching. As can be seen from Fig. 13, the braking surface 24 that extends in the manner of a cam is formed in the area close to the axis, for example, if in the braking surfaces 24 that lie against the inside wall of the housing or the brake lining on the inside wall of the housing, respectively, (as is the case when the tow cab~e is being paid out), the edge areas of the centrifugal weights 10, 11, respectively that are adjacent to the braking area 24 in the vicinity of the axis slope gradually away from the inside wall of the housing (at least in the direction towards the free end of the centrifugal weights 10, 11, respectively).
In most instances, the pay-out and take-up device is for tow cables used on tow lifts, usually have two centrifugal weights, as has been shown in the illustrations. In this case, both centrifugal weights, or only one of the centrifugal weights may be provided with cam-like braking surfaces 24 and rotatable brake shoes 25 as described in this invention.
It is not essential that the centrifugal weights 10, 11 respectively are formed in each case as a single component, ~9373 as has been shown in the drawings, on which the cam-like braking surface 25 is formed and on which the brake shoes 25 .
are mounted in such a manner as to be rotatable. It is also possible to use centrifugal weights that consist of two or several parts, for example, in such a manner that a main body that forms the principal mass of the centriEugal weight may be connected to one or more additional components in such a manner that also rotate with the main body when the tow cable drum is rotated, in which connection the cam-like and projecting brake surface 24 is formed on these additional,components of the centrifugal weight and/or the rotatable brake shoe furthest from the axis~is also mounted on it.
In a known device based on this principle, a brake - shoe that is rotatably mounted about an axis parallel to the axis of rotation of the centrifugal weight is arranged between two stops, this brake shoe having two braking surfaces that are nclined towards each other and which extend beyond the outer edge of the centrifugal weight (see Swiss Patent No. 502,214).
However, this device has the main disadvantage that when the tow cable is being taken up and paid out there are only insignificant differences with respect to the point of application of the rotatable brake shoe on the brake lining bonded to the inside wall of the housing and accordingly the resulting differences in the braking effect are far too small.
In another device based on the above principle, it is true that the requirement that there be a higher braking moment when the tow cable is being paid out than when the tow cahle is being taken up can be better satisfied. However, this device has the disadvantage that in order to vary the lever arm of the centrifugal weight the axis of the centrifugal weight is ;373 guided in a slot (see Swiss Patent No. 348,176). Compared to a fixed axis of rotation this does not provide a sufficiently secure mounting for the centrifugal weight about its axis of rotation, so that the centrifugal weight can tilt and topple, this being prejudicial to the desired function.
The present invention thus provides a take-up and pay-out device for tow cables of tow lifts in accordance with the aforesaid principle by which a sufficiently large difference in the braking effect during pay-out of t,he cable vis-a-vis the taking up of the cable is ensured without the stable position-ing of the centrifugal weight being in any way impaired.
According to the present invention there is provided a tow rope pull-out and retracting device, comprising a housing havin~aninternalsurface,areeldisposedwithinsaidhousingfortakin~up and payingout atowrope,a retracting spring coupledtosaidreel,at least one flyweight pivotally mounted on said reel about a first axis, said flyweight having a protruding braking surface near said axis adapted to engage said internal surface in one direction of rotation and a brake shoe pivotally mounted about a second axis, remote from said first axis, and adapted to engage said inter-nal surface in an opposite direction of rotation, whereby a dif-ferent braking force is produced in opposite senses of rotation.
Thus according to the present invention, an area fur-thest from the axis the centrifugal weight has a brake shoe that is rotatably mounted about an axis, parallel to the axis of ~1~93~3 rotation of the centrifugal weight, between two stops that are provided and which, in that area close to the axis, has a braking surface that extends preferably in the manner of a cam.
Using the device according to the invention it is possible to obtain a considerable difference in braking performance when the cable is being taken up, on the one hand, and when the tow cable is being paid out on the other, because the braking surface that protrudes preferably like a cam that is effective when the tow cable is being paid out and the braking shoe that is in its operating position when the tow cable is being taken up are located a relatively grea, distance from each other. In addition, the device according to the present invention has good stability because in that place where the loading is particularly great, namely, in the area of the centrifugal weight that is close to the axis a stable braking surface preferably in the form of a cam-like projection is formed, this contributing to the direct transfer of force to the axis of the centrifugal weight. The rotatable brake shoe is located in the area furthest from the axis, that is to say, where the loading is significantly less. Thus neither the brake shoe nor its mountlng are subjected to excessive loads.
The present invention will be further described by way of the accompanying drawings, in which:-Fig. 1 is a cross-section through the axis of the cable drum according to I-I of Fig. 2 of a pay-out and take-up devlce according to one embodiment of the present invention;
Fig. 2 is a cross section in the line II-II of the device of Fig. 1 with the centrifugal weight being in the position for paying out the tow cable;
Fig. 3 is a similar cross-section to Fig. 2 when the tow cable is being taken up;
Fig. 4 is an enlarged cross section on the line IV-IV
of Fig. 3;
Fig. 5 is a vertical cross section on the line V-V
of Fig. 6;
Fig. 6 is a cross section on the line VI-VI of Fig. 5 with the centrifugal weight being in the position adopted when the tow cable is being paid out;
Fig. 7 is a similar section to Fig. 6 of a further embodiment of the device of the present invention when the tow cable is being taken up;
Fig. 8 is a vertical section on the line VIII-VIII
of Figs. 9 and lO;
Fig. 9 is a cross section on the line IX-IX of Fig. 8, with the centrifugal weight in the position for paying out the cable;
Fig. 10 is a similar cross section when the tow cable is being taken up, in a further embodiment of the device of the present invention;
Fig. ll is a vertical section through the axis of the cable drum;
~ig. 12 is a normal section of a variation for Figs.
8 - 10; and I Fig. 13 is a normal section of a variation for the cam-like braking surface of the centrifugal weight.
The take-up and pay-out device according to Figs. 1 - 4 comprises a housing 1, connected through the clamping bracket 2 and the suspension column (not shown) to the circulating device.
The housiny l is extended laterally by the spring housing 3, this containing the return spring 4. The spring 4, in the form of a coil spring, is secured at one end to the housing 3 and at the other to a coiling stud mounted on the shaft 5, this being connected through a coupling to the cable drum 6 for the tow cable. Two studs 8, 9, arranged on the cable drum 6, carry ~9373 the two centrifugal weights 10, 11. A brake lining 12 is on the inside wall of the housing 1. In the areas closest to the axis the centrifugal weights 10, 11 each have a braking surface 24 that extends in the manner of a cam. In the areas furthest from the axis each centrifugal weight 10, 11 has a brake shoe 25 mounted about an axis 26 parallel to the axes 8, 9 of the centrifugal weights, between two stops 27, 28. When the tow cable 7 is paid out in the direction indicated by the arrow 17 (Fig. 2) the cable drum 6 together with the centrifugal weights 10 and 11 rotates in the direction indicated by the arrow 18.
The braking surfaces 24 thereupon come into contact with the brake lining 12. The level-like brake shoes 25 lie against the stops 27 and are inoperative. Because of the proximity of the studs 8 and 9 of the centrifugal weights 10 and 11, respectively, the brake surfaces are pressed extremely hard against the brake lining 12. This results in an extremely high braking moment when the tow cable 7 is paid out. This in its turn results in a very smooth acceleration of the skier as he or she starts off.
When the tow cable 7 is taken up with the empty tow stirrup the cable drum 6 together with the centrifugal weights 10, 11 rotates in the direction of the arrow 19 (Fig. 3). The brake shoes 25 contact the stops 28 and their braking surfaces are pressed against the brake lining 12 whereas the braking surfaces 24 of the centrifugal weights 10, 11 that are close to the axis are lifted away from the brake lining. The force with which the brake shoes 25 press against the brake lining is relatively slight. For this reason the braking moment is also slight, and this results in a rapid but easily slowed taking-up of the tow cable. In the embodiment according to Figs. 5 - 7, the housing 1 of the take-up and pay-out device has a drum-like extens'~on 35, this forming a part of the inner wall of the housing and having a brake lining 36. As in the case of the embodiment according to Figs. 1 - 4 there is a braking surface 24 that extends in the manner of a cam provided on the centrifugal weights 10, 11 in that area of the said weights nearest to the axle, but which, in this case, is now opposite the drum-like extension 35 of the inside of the housing. In the same manner as in the embodiment according to Figs. 1 - 4 in that area furthest from the axes there is on each centrifugal weight a brake shoe 25, that is rotatably mounted about an axis 26 parallel to the centrifugal weight axes 8 and 9. When the tow cable is paid out in the direction of the arrow 17 and the cable drum 6 together with centrifugal weights 10 and 11 rotates in the direction of the arrow 18 the braking surfaces 24 are pressed extremely hard against the brake lining 36. This results in a great braking moment when the tow cable is paid out. The brake shoes 25 then abut against the stops 27 and are inoperative. When the tow cable 7 is taken up the cable drum and the centrifugal weights 10, 11 rotate in the direction of the arrow 19. The brake shoes 25 now lie against the stops 28 and are pressed somewhat less strongly against the brake lining 12. The result of this is a smaller braking moment when the tow cable is taken up. The effect of the high braking moment when the cable is paid out and the smaller braking moment when the tow cable is taken up can be increased if the brake lining 36 has a nigher coefficient of friction than the brake lining 12.
For all practical purposes the embodiment of the device according to Fig. 8 - 10 differs from the embodiment according to Figs. 1 - 4 only in the formation of the rotatable brake shoes 25 in the form of wire stirrups of steel wire. Thus the brake shoes 25 can be produced in a particularly economical manner and, in addition, can be mounted in a very simple manner ~ ~ ~9373 on the centrifugal weights 10, 11, respectively. In this respect, all that is required is a simple hole in the centrifugal weight 10, 11, respectively, into which one arm of the wire stirrup is inserted as an axle 26.
In the embodiment of the device according to Figs. 8 and 10 there are once again stirrup-like rotatable brake shoes in the area of the centrifugal weights 10, 11, furthest from the axis, these lying between two stops 27 and 28, whereas in the area of the centrifugal weights 10 and 11 adjacent the axis there is in each case a brake surface 24 that extends in the manner of a cam. The function of the take-up and pay-out device àccording to Figs. 8 and 10 is the same as in the embodiment of the device according to Figs. 1 - 4.
The effect of the considerably greater braking moment of the centrifugal brake when the tow cable 7 is taken up in comparison with the braking moment when the tow cable 7 is paid out can in all embodiments of the device be increased, e.g., by the fact that the cam-like braking surface 24 has a higher coefficient of friction than the braking surface of the rotatable brake shoe 25. This is the case if the centrifugal - weights 10, 11 are of grey cast iron, and brake surfaces 24 that extend in the manner of a cam are also of grey cast iron, whereas the rotatable brake shoes 25 or their braking surfaces, respectively, are of steel, because grey cast iron has a greater coefflcient of friction than steel. This effect can be increased even further by coating the braking surfaces of the rotatable brake shoes 25, for example, with plastic, or by forming the rotatable brake shoes 25 themselves or plastic.
In the case of the stirrup-like brake shoes 25 according to Figs. 8 - 10, the provislon of a bearing sleeve on the arm of the stirrup-like brake shoe that works with the inside wall of the housing 1 or a brake lining 12 applied thereto, 3~73 respectively, when the tow cable 7 is taken up, is also possible.
In the embodiments illustrated, the stops 27, 28 to limit the movement of the brake shoe 25 are formed on the centrifugal weights 10, 11, themselves. However, there is an equivalent solution in the fact that at least one of the two stops, particularly the stop 28, can be formed on the cable drum 6. On the basis of a variation of the embodiment according to Figs. 8 and 10, Figs. 11 and 12 show the arrangement of both stops 27, 28 for the rotatable brake shoes 25 on the cable drum 6.
The braking surface 24 that is close to the axis does not necessarily have to be formed by a cam of the centrifugal weight 10, 11, respectively, that is limited on both sides by step-like notching. As can be seen from Fig. 13, the braking surface 24 that extends in the manner of a cam is formed in the area close to the axis, for example, if in the braking surfaces 24 that lie against the inside wall of the housing or the brake lining on the inside wall of the housing, respectively, (as is the case when the tow cab~e is being paid out), the edge areas of the centrifugal weights 10, 11, respectively that are adjacent to the braking area 24 in the vicinity of the axis slope gradually away from the inside wall of the housing (at least in the direction towards the free end of the centrifugal weights 10, 11, respectively).
In most instances, the pay-out and take-up device is for tow cables used on tow lifts, usually have two centrifugal weights, as has been shown in the illustrations. In this case, both centrifugal weights, or only one of the centrifugal weights may be provided with cam-like braking surfaces 24 and rotatable brake shoes 25 as described in this invention.
It is not essential that the centrifugal weights 10, 11 respectively are formed in each case as a single component, ~9373 as has been shown in the drawings, on which the cam-like braking surface 25 is formed and on which the brake shoes 25 .
are mounted in such a manner as to be rotatable. It is also possible to use centrifugal weights that consist of two or several parts, for example, in such a manner that a main body that forms the principal mass of the centriEugal weight may be connected to one or more additional components in such a manner that also rotate with the main body when the tow cable drum is rotated, in which connection the cam-like and projecting brake surface 24 is formed on these additional,components of the centrifugal weight and/or the rotatable brake shoe furthest from the axis~is also mounted on it.
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A tow rope pull-out and retracting device, com-prising a housing having an internal surface, a reel disposed with-in said housing for taking up and paying out a tow rope, a retracting spring coupled to said reel, at least one flyweight pivotally mounted on said reel about a first axis, said flyweight having a protruding braking surface near said axis adapted to engage said internal surface in one direction of rotation and a brake shoe pivotal-ly mounted about a second axis remote from said first axis, and adapted to engage said internal surface in an opposite di-rection of rotation, whereby a different braking force is pro-duced in opposite senses of rotation.
2. A device according to claim 1, wherein said pro-truding braking surface is in the form of a boss on the fly-weight near the first axis.
3. A device according to claim 2, wherein said brake shoe is pivotal between two extreme positions defined by end stops, rotation in said one direction causing said brake shoe to trail without making fin engagement with said internal sur-face and rotation in said opposite direction causing said brake shoe to come up against one said end stop and to make fin en-gagement with said internal surface.
4. A device according to claim 3, wherein said brake shoe when making fin engagement with the internal surface lies substantially in a radial direction so as to protrude beyond the flyweight and when trailing lies at an angle to the radial direction.
5. A device according to claim 1, in which the pro-truding braking surface of the flyweight is in the form of a cam.
6. A device according to claim 1 or 2, in which the brake shoe is made of steel.
7. A device according to claim 1 or 2, in which the brake shoe is made of plastic.
8. A device according to claim 1 or 2, in which the brake shoe has a braking surface that is coated with plastic.
9. A device according to claim 1 or 2, in which the brake shoe is in the form of a stirrup.
10. A device according to claim 1 or 2, in which the coefficient of friction of the protruding braking surface is greater than the coefficient of friction of the brake shoe.
11. A device according to claim 1 or 2, in which the flyweight together with the protruding braking surface is made of grey cast iron.
12. A device according to claim 1, in which said in-ternal surface of the housing is provided with at least one brake lining.
13. A device according to claim 12, in which the brake shoe is provided with a brake lining which has the same coefficient of friction as the brake lining on said internal surface.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ATA566/80 | 1980-02-04 | ||
| AT0056680A AT364776B (en) | 1980-02-04 | 1980-02-04 | IN- AND EXTENSION DEVICE FOR TOW ROPES OF TOW LIFTS |
| AT507180A AT375887B (en) | 1980-10-13 | 1980-10-13 | IN- AND EXTENSION DEVICE FOR TOWING ROPES OF TOWING LIFTS |
| ATA5071/80 | 1980-10-13 | ||
| AT24081 | 1981-01-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1149373A true CA1149373A (en) | 1983-07-05 |
Family
ID=27146039
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000369995A Expired CA1149373A (en) | 1980-02-04 | 1981-02-03 | Cable take-up and pay-out device for tow-lift cables |
Country Status (7)
| Country | Link |
|---|---|
| CA (1) | CA1149373A (en) |
| DE (1) | DE3102975A1 (en) |
| FI (1) | FI72085C (en) |
| IT (2) | IT1143350B (en) |
| NO (1) | NO150073C (en) |
| SE (1) | SE8100449L (en) |
| YU (1) | YU29481A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2725253A3 (en) * | 2012-10-26 | 2017-11-01 | Kudu International Inc. | Centrifugal backspin brake |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3802012A1 (en) * | 1988-01-25 | 1989-07-27 | Vorwerk Co Interholding | CABLE REEL FOR VACUUM CLEANER |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH348176A (en) * | 1960-04-14 | 1960-08-15 | Bachmann & Co Ag | Tow brake for ski lift |
| CH473702A (en) * | 1968-02-26 | 1969-06-15 | Habegger Ag Maschf | Tow brake for ski lift |
| CH502214A (en) * | 1969-01-27 | 1971-01-31 | Staedeli Maschinenfabrik W | Rope retraction device for the towing device of a ski tow lift |
-
1981
- 1981-01-26 SE SE8100449A patent/SE8100449L/en not_active Application Discontinuation
- 1981-01-28 FI FI810247A patent/FI72085C/en not_active IP Right Cessation
- 1981-01-29 DE DE19813102975 patent/DE3102975A1/en active Granted
- 1981-02-03 YU YU00294/81A patent/YU29481A/en unknown
- 1981-02-03 CA CA000369995A patent/CA1149373A/en not_active Expired
- 1981-02-03 IT IT67143/81A patent/IT1143350B/en active
- 1981-02-03 NO NO810365A patent/NO150073C/en unknown
- 1981-02-04 IT IT8152885U patent/IT8152885V0/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2725253A3 (en) * | 2012-10-26 | 2017-11-01 | Kudu International Inc. | Centrifugal backspin brake |
Also Published As
| Publication number | Publication date |
|---|---|
| NO150073C (en) | 1984-08-15 |
| DE3102975A1 (en) | 1982-01-14 |
| YU29481A (en) | 1983-10-31 |
| FI72085C (en) | 1987-04-13 |
| FI810247L (en) | 1981-08-05 |
| IT8167143A0 (en) | 1981-02-03 |
| NO810365L (en) | 1981-08-05 |
| IT8152885V0 (en) | 1981-02-04 |
| NO150073B (en) | 1984-05-07 |
| IT1143350B (en) | 1986-10-22 |
| SE8100449L (en) | 1981-08-05 |
| FI72085B (en) | 1986-12-31 |
| DE3102975C2 (en) | 1987-07-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |