CA1227188A - Winch drive means - Google Patents
Winch drive meansInfo
- Publication number
- CA1227188A CA1227188A CA000476978A CA476978A CA1227188A CA 1227188 A CA1227188 A CA 1227188A CA 000476978 A CA000476978 A CA 000476978A CA 476978 A CA476978 A CA 476978A CA 1227188 A CA1227188 A CA 1227188A
- Authority
- CA
- Canada
- Prior art keywords
- winch
- drive means
- hand
- zones
- worm
- 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
- B66—HOISTING; LIFTING; HAULING
- B66D—CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS
- B66D5/00—Braking or detent devices characterised by application to lifting or hoisting gear, e.g. for controlling the lowering of loads
- B66D5/02—Crane, lift hoist, or winch brakes operating on drums, barrels, or ropes
- B66D5/24—Operating devices
Abstract
ABSTRACT
Winch drives for intermittently adjusting tension in con-veyors must be braked when inoperative. An exposed band brake is prone to damage and oiling; an enclosed disc brake held applied by an end thrust exerted by the load on the winch can be bypassed by a one-way clutch in only one driving direction and causes excessive drag in the other driving direction. By dispensing with the one-way clutch and introducing a double-helical driving connection, there is created an opposing axial force which exceeds the above-mentioned end thrust and releases the disc brake automatically in both driving directions.
Winch drives for intermittently adjusting tension in con-veyors must be braked when inoperative. An exposed band brake is prone to damage and oiling; an enclosed disc brake held applied by an end thrust exerted by the load on the winch can be bypassed by a one-way clutch in only one driving direction and causes excessive drag in the other driving direction. By dispensing with the one-way clutch and introducing a double-helical driving connection, there is created an opposing axial force which exceeds the above-mentioned end thrust and releases the disc brake automatically in both driving directions.
Description
~Z~71~38 This invention relates to winch drive means, particularly but not exclusively for the intermittent adjustment of a con-tenuous load, for example for intermittently adjusting the tension in conveyor systems in coal mines and the like. Such means require to be braked when inoperative.
One known arrangement of winch drive means has a band brake around the periphery of the winch drum, but as the brake is ox-posed it is prone to physical damage and to contamination by dirt and possibly oil.
Another known arrangement of winch drive means comprises a reversible motor connected to a shaft provided with a worm, a warmly meshing with the worm, a winch drum driven by the warmly, and an enclosed friction brake comprising a face on a housing which contains the worm and warmly and a co-operating disc which is axially fixed relative to the worm shaft and is drivable connected to said shaft by a one-way clutch. The brake is applied automatically when the winch is not operating by an end thrust exerted on the worm shaft in the brake-applying direction by the load on the winch. When the motor is rotating in one direction, the one-way clutch overruns and the worm shaft can be driven without hindrance even though the brake is still held applied by the load on the winch, but when the motor is no-toting in the other direction the one-way clutch is locked and, as the brake is still held applied by the load on the winch, the motor has to overcome the action of the brake in order to drive the worm shaft. The resulting frictional drag causes undesir-able heating and wear.
The object of the present invention is to avoid the disk advantages of both of the aforementioned known arrangements.
According to the invention, winch drive means comprise a reversible motor, a driving member connecting the motor to a 'I
shaft provided with a worm, a warmly meshing with the worm, and a winch drum driven by the warmly, wherein a friction brake comprising a face on a housing which contains the worm and warmly and a co-operating disc rigidly secured on the worm shaft is applied automatically when the winch is not operating by an end thrust exerted on the worm shaft in the brake-applying direction by the load on the winch and wherein double-helical drive means between the drive member and the worm shaft exert an opposing force which exceeds said end thrust so as to release the brake automatically when the winch is operating whatever the direction of rotation of the motor.
A preferred embodiment of the invention will now be desk cried, by way of example, with reference to the accompanying drawings of which:-Fig. 1 is a sectional side elevation of winch drive means;
Fig. 2 is a side elevation of a detail of said means shown in section in Fig. l; and Fig. 3 shows diagrammatically a detail of an alternative embodiment of the invention.
Referring now to Figs. 1 and 2, winch drive means comprise a reversible electric motor 10 having a driving cylindrical gear 11 rigidly secured by means including a key 12 on its shaft 13.
The gear 11 meshes with a driven cylindrical gear 14 constitute in a driving member connected by double-helical drive means hereinafter described to one end of a shaft 15 provided with a worm 16. The worm 16 meshes with a warmly 17 which drives a winch drum (not shown), said worm and warmly being contained within a housing 18. The driven cylindrical gear 14 is support-Ed by a thrust bearing 19 carried by an end casing 20 secured between the housing 18 and the motor 10. A friction brake for the winch drive means comprises an annular member 21 secured to lox the housing 18 and provided with a friction face 22; and a co-operating disc 23 rigidly secured by means comprising a key 24, a castle nut 25 and a tab-washer 26 on the other end of the worm shaft 15 and having bonded to it a ring 27 of friction material, the arrangement being such that the brake is applied automatic gaily when the winch is not operating by an end thrust indicated by the arrow A exerted on the worm shaft 15 in the brake-applying direction by the load on the winch. The brake is enclosed by a cover 28 secured to the housing 18. The double-helical drive means for connecting the driven cylindrical gear 14 to the worm shaft 15 comprise a left-hand acme-threaded zone 29 and a right-hand acme-threaded zone 30 in an axial bore through said gear, the left-hand zone 29 engaging with a mating thread on a first collar 31 rigidly secured by means including a key 32 to the worm shaft 15 and the right-hand zone 30 engage in with a mating thread on a second collar 33 rigidly secured by means including a key 34 to said shaft. Shims 35 may be inserted as required between the two collars 31 and 33 to enable their respective key-ways to be aligned with the associated keys 32 and 34 during assembly, and additional means for rigidly securing both of said collars to the worm Swift 15 comprise a castle nut 36 and a tab-washer 37.
In operation, with particular reference to Fig. 2, when the motor 10 operates the winch by rotating the driven cylindrical gear 14 in the direction of the arrow B, the axial component indicated by the arrow C of the force exerted by said gear on the first collar 31 opposes and exceeds the end thrust indicated by the arrow A exerted on the worm shaft 15 by the load on the winch so as to release the brake automatically. Similarly, when the motor 10 is run in reverse to operate the winch by rotating the gear 14 in the direction of the arrow D, the axial component ~227~
also indicated by the arrow C of the force exerted by said gear on the second collar 33 opposes and exceeds the aforesaid end thrust A so as again to release the brake automatically. Thus there are provided winch drive means with an enclosed brake which are not subjected to frictional drag whatever the direct lion of rotation of the motor 10.
In one alternative embodiment of the invention a detail of which is shown diagrammatically in Fig. 3, the double-helical drive means comprise a left-hand helically-splined zone 40 and a right-hand helically-splined zone 41 formed on the worm shaft 15, said zones being shown in full lines. The zone 40 engages with a mating splinted zone 42 formed in the bore of the driven cylindrical gear 14, and the zone 41 engages with a mating splinted zone 43 formed in said bore, the zones 42 and 43 being shown in dotted lines. The splints in the left-hand zones 40 and 42 are staggered in relation to the splints in the right-hand zones 41 and 43. In operation, when the gear 14 is driven in the direction of the arrow E, the axial component indicated by the arrow F of the force exerted by said gear on the splinted zone 40 of the worm shaft 15 opposes and exceeds the end thrust indicated by the arrow A exerted on said shaft by the load on the winch so as to release the brake automatically. Similarly, when the gear 14 is driven in the direction of the arrow G, the axial component also indicated by the arrow F of the force exerted by said gear on the splinted zone 41 of the worn shaft 15 opposes and exceeds the aforesaid end thrust A so as again to release the brake automatically.
In one modification applicable to both the preferred embody immunity and the foregoing alternative embodiment, the gears drive-ably connecting the motor 10 to the worm shaft 15 are other than cylindrical, for example of bevel type. In another modification lo 38 applicable to both the preferred embodiment and the foregoing alternative embodiment, the gears drivable connecting the motor lo to the worm shaft 15 are dispensed with and the driving member constitutes a coupling sleeve or the like directly con-nectir.g the motor 10 co-axially to the worm shaft 15 by way of double-helical threads or splints.
In another alternative embodiment of the invention similar in principle to said one alternative embodiment thereof, the gears drivable connecting the motor 10 to the worm shaft 15 are cylindrical and the double-helical drive means comprise left-hand and right-hand helically-toothed zones on the driving gear meshing with mating toothed zones on the driven gear, the teeth in the left-hand zones being staggered in relation to the teeth in the right-hand zones.
One known arrangement of winch drive means has a band brake around the periphery of the winch drum, but as the brake is ox-posed it is prone to physical damage and to contamination by dirt and possibly oil.
Another known arrangement of winch drive means comprises a reversible motor connected to a shaft provided with a worm, a warmly meshing with the worm, a winch drum driven by the warmly, and an enclosed friction brake comprising a face on a housing which contains the worm and warmly and a co-operating disc which is axially fixed relative to the worm shaft and is drivable connected to said shaft by a one-way clutch. The brake is applied automatically when the winch is not operating by an end thrust exerted on the worm shaft in the brake-applying direction by the load on the winch. When the motor is rotating in one direction, the one-way clutch overruns and the worm shaft can be driven without hindrance even though the brake is still held applied by the load on the winch, but when the motor is no-toting in the other direction the one-way clutch is locked and, as the brake is still held applied by the load on the winch, the motor has to overcome the action of the brake in order to drive the worm shaft. The resulting frictional drag causes undesir-able heating and wear.
The object of the present invention is to avoid the disk advantages of both of the aforementioned known arrangements.
According to the invention, winch drive means comprise a reversible motor, a driving member connecting the motor to a 'I
shaft provided with a worm, a warmly meshing with the worm, and a winch drum driven by the warmly, wherein a friction brake comprising a face on a housing which contains the worm and warmly and a co-operating disc rigidly secured on the worm shaft is applied automatically when the winch is not operating by an end thrust exerted on the worm shaft in the brake-applying direction by the load on the winch and wherein double-helical drive means between the drive member and the worm shaft exert an opposing force which exceeds said end thrust so as to release the brake automatically when the winch is operating whatever the direction of rotation of the motor.
A preferred embodiment of the invention will now be desk cried, by way of example, with reference to the accompanying drawings of which:-Fig. 1 is a sectional side elevation of winch drive means;
Fig. 2 is a side elevation of a detail of said means shown in section in Fig. l; and Fig. 3 shows diagrammatically a detail of an alternative embodiment of the invention.
Referring now to Figs. 1 and 2, winch drive means comprise a reversible electric motor 10 having a driving cylindrical gear 11 rigidly secured by means including a key 12 on its shaft 13.
The gear 11 meshes with a driven cylindrical gear 14 constitute in a driving member connected by double-helical drive means hereinafter described to one end of a shaft 15 provided with a worm 16. The worm 16 meshes with a warmly 17 which drives a winch drum (not shown), said worm and warmly being contained within a housing 18. The driven cylindrical gear 14 is support-Ed by a thrust bearing 19 carried by an end casing 20 secured between the housing 18 and the motor 10. A friction brake for the winch drive means comprises an annular member 21 secured to lox the housing 18 and provided with a friction face 22; and a co-operating disc 23 rigidly secured by means comprising a key 24, a castle nut 25 and a tab-washer 26 on the other end of the worm shaft 15 and having bonded to it a ring 27 of friction material, the arrangement being such that the brake is applied automatic gaily when the winch is not operating by an end thrust indicated by the arrow A exerted on the worm shaft 15 in the brake-applying direction by the load on the winch. The brake is enclosed by a cover 28 secured to the housing 18. The double-helical drive means for connecting the driven cylindrical gear 14 to the worm shaft 15 comprise a left-hand acme-threaded zone 29 and a right-hand acme-threaded zone 30 in an axial bore through said gear, the left-hand zone 29 engaging with a mating thread on a first collar 31 rigidly secured by means including a key 32 to the worm shaft 15 and the right-hand zone 30 engage in with a mating thread on a second collar 33 rigidly secured by means including a key 34 to said shaft. Shims 35 may be inserted as required between the two collars 31 and 33 to enable their respective key-ways to be aligned with the associated keys 32 and 34 during assembly, and additional means for rigidly securing both of said collars to the worm Swift 15 comprise a castle nut 36 and a tab-washer 37.
In operation, with particular reference to Fig. 2, when the motor 10 operates the winch by rotating the driven cylindrical gear 14 in the direction of the arrow B, the axial component indicated by the arrow C of the force exerted by said gear on the first collar 31 opposes and exceeds the end thrust indicated by the arrow A exerted on the worm shaft 15 by the load on the winch so as to release the brake automatically. Similarly, when the motor 10 is run in reverse to operate the winch by rotating the gear 14 in the direction of the arrow D, the axial component ~227~
also indicated by the arrow C of the force exerted by said gear on the second collar 33 opposes and exceeds the aforesaid end thrust A so as again to release the brake automatically. Thus there are provided winch drive means with an enclosed brake which are not subjected to frictional drag whatever the direct lion of rotation of the motor 10.
In one alternative embodiment of the invention a detail of which is shown diagrammatically in Fig. 3, the double-helical drive means comprise a left-hand helically-splined zone 40 and a right-hand helically-splined zone 41 formed on the worm shaft 15, said zones being shown in full lines. The zone 40 engages with a mating splinted zone 42 formed in the bore of the driven cylindrical gear 14, and the zone 41 engages with a mating splinted zone 43 formed in said bore, the zones 42 and 43 being shown in dotted lines. The splints in the left-hand zones 40 and 42 are staggered in relation to the splints in the right-hand zones 41 and 43. In operation, when the gear 14 is driven in the direction of the arrow E, the axial component indicated by the arrow F of the force exerted by said gear on the splinted zone 40 of the worm shaft 15 opposes and exceeds the end thrust indicated by the arrow A exerted on said shaft by the load on the winch so as to release the brake automatically. Similarly, when the gear 14 is driven in the direction of the arrow G, the axial component also indicated by the arrow F of the force exerted by said gear on the splinted zone 41 of the worn shaft 15 opposes and exceeds the aforesaid end thrust A so as again to release the brake automatically.
In one modification applicable to both the preferred embody immunity and the foregoing alternative embodiment, the gears drive-ably connecting the motor 10 to the worm shaft 15 are other than cylindrical, for example of bevel type. In another modification lo 38 applicable to both the preferred embodiment and the foregoing alternative embodiment, the gears drivable connecting the motor lo to the worm shaft 15 are dispensed with and the driving member constitutes a coupling sleeve or the like directly con-nectir.g the motor 10 co-axially to the worm shaft 15 by way of double-helical threads or splints.
In another alternative embodiment of the invention similar in principle to said one alternative embodiment thereof, the gears drivable connecting the motor 10 to the worm shaft 15 are cylindrical and the double-helical drive means comprise left-hand and right-hand helically-toothed zones on the driving gear meshing with mating toothed zones on the driven gear, the teeth in the left-hand zones being staggered in relation to the teeth in the right-hand zones.
Claims (5)
1. Winch drive means comprising a reversible motor, a driving member connecting the motor to a shaft provided with a worm, a wormwheel meshing with the worm, and a winch drum driven by the wormwheel, wherein a friction brake comprising a face on a housing which contains the worm and wormwheel and a co-operating disc rigidly secured on the worm shaft is applied automatically when the winch is not operating by an end thrust exerted on the worm shaft in the brake-applying direction by the load on the winch and wherein double-helical drive means between the driving member and the worm shaft exert an opposing axial force which exceeds said end thrust so as to release the brake automatically when the winch is operating whatever the direction of rotation of the motor.
2. Winch drive means according to claim 1, wherein the driving member is the driven one of a pair of gears, the driving one of which is connected to the motor.
3. Winch drive means according to claim 1 or claim 2, wherein the double-helical drive means comprise left-hand and right-hand threaded zones on the worm shaft engaging with mating threaded zones in a bore of the driving member.
4. Winch drive means according to claim 1 or claim 2, wherein the double-helical drive means comprise left-hand and right-hand helically-splined zones on the worm shaft engaging with mating splined zones in a bore of the driving member, the splines in the left-hand zones being staggered in relation to the splines in the right-hand zones.
5. Winch drive means according to claim 2, wherein the gears are cylindrical and the double-helical drive means comprise left-hand and right-hand helically-toothed zones on the driving gear meshing with mating toothed zones on the driven gear, the teeth in the left-hand zones being staggered in relation to the teeth in the right-hand zones.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB848407523A GB8407523D0 (en) | 1984-03-22 | 1984-03-22 | Winch drive means |
| GB8407523 | 1984-03-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1227188A true CA1227188A (en) | 1987-09-22 |
Family
ID=10558544
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000476978A Expired CA1227188A (en) | 1984-03-22 | 1985-03-20 | Winch drive means |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1227188A (en) |
| GB (2) | GB8407523D0 (en) |
| ZA (1) | ZA852125B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2778648B1 (en) * | 1998-05-15 | 2000-08-04 | Materiel Et Outillage Rationne | WINCH FOR TENSIONING A CABLE OF AN ASSEMBLY AS OPENING, SECURITY DEVICE AND INSTALLATION PROVIDED WITH THE WINCH |
| CN103511524A (en) * | 2012-06-27 | 2014-01-15 | 甘亚冰 | Diversion gravity braking mechanism, lifting winch and lift transmission board |
-
1984
- 1984-03-22 GB GB848407523A patent/GB8407523D0/en active Pending
-
1985
- 1985-03-18 GB GB08506947A patent/GB2155888B/en not_active Expired
- 1985-03-20 CA CA000476978A patent/CA1227188A/en not_active Expired
- 1985-03-21 ZA ZA852125A patent/ZA852125B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| GB8506947D0 (en) | 1985-04-24 |
| GB8407523D0 (en) | 1984-05-02 |
| GB2155888A (en) | 1985-10-02 |
| GB2155888B (en) | 1987-01-28 |
| ZA852125B (en) | 1985-11-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |