CA1066921A - Drive power transmission element - Google Patents
Drive power transmission elementInfo
- Publication number
- CA1066921A CA1066921A CA288,520A CA288520A CA1066921A CA 1066921 A CA1066921 A CA 1066921A CA 288520 A CA288520 A CA 288520A CA 1066921 A CA1066921 A CA 1066921A
- Authority
- CA
- Canada
- Prior art keywords
- wheel
- groove
- constriction
- filament
- minor
- 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
Landscapes
- Pulleys (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A positive drive power transmission element in the form of a wheel adapted to be mounted non-rotatably on a shaft or axle in which the wheel has a peripheral surface provided with a unique groove receiving a flexible power transmission element, such as a rope, in which the groove is provided with a plurality of circumferentially spaced impressions which are of substantially semi-frustoconical configuration in which the directions of taper lie on the line of circumference rather than along the radii of the wheel.
A positive drive power transmission element in the form of a wheel adapted to be mounted non-rotatably on a shaft or axle in which the wheel has a peripheral surface provided with a unique groove receiving a flexible power transmission element, such as a rope, in which the groove is provided with a plurality of circumferentially spaced impressions which are of substantially semi-frustoconical configuration in which the directions of taper lie on the line of circumference rather than along the radii of the wheel.
Description
~0669Zl The present invention generally relates to a power , transmission element incorporating a positive drive connection between a rotatable wheel and a flexible drive or driven member in the form of a rope in which the periphery of the wheel in-cludes a pair of divergent surfaces thus having a plurality of circumferentially spaced and arranged impressions or grooves therein which are substantially frustoconical in shape with the tapering portions of the frustoconical shape extending along the circumference of the wheel rather than radially thereof to ;~ 10 provide a positive drive connection between the wheel and rope.
Transmission of power by using a flexible power trans-mitting element engaged with a pulley rotatable about an axle has been used for many years and has included pulleys with flat surfaces for engaging flat drive belts, pulleys with a V-shaped groove for engaging V belts and similar types of structures in which friction between the pulley and flexible element serves to transmit power and to perform work. Various efforts have :, .. .
~ been made to modify rope pulleys to increase the frictional ; engagement between the rope and pulley but such devices usually employ radial converging surfaces, such as ribs or lugs, on the radially converging surfaces of the pulley groove which increase friction but even so~ slippage will occur between the : .
~ rope and pulley when a sufficient load iB encountered when the ,~ compressed diameter of the rope or cable i8 insertable in the ; narrowest construction of the walls of the pulley or sheave.
~; An ob;ect of the invention is to provlde a positive drive element for the transmission of power between a com-pressible filament such as a rope and a wheel having a uniquely ; constructed peripheral groove in which slippage is eliminated by compression of the filament or rope.
A still further object of the invention is to provide a positive drive transmission element which is quite simple in . .
construction, easy to utilize in various power transmission , .: --1--"~ , - ~ .b~/~XY~ ~ ~
1~6~;9Z~
` ~
: arrangements and efficient in positive transfer of driving force.
; The present invention provides a positive drive power transmission element comprising a generally circular wheel ~ .
adapted to be rigidly connected to an axle for rotational ::
: movement about an axle, the wheel including a peripheral groo~e .~ -receiving a flexible, compressible filament and means incor- .
porated into the groove to provide a positive driving connection ..
between the wheel and filament, the means including a plurality ~ --of equally spaced circumferentially extending semi-frustoconical . impressions in each wall of the groove, the impressions being :: arranged in pairs including a minor constriction area having .
: wall portions spaced apart a minimum distance and a major constriction area having a pair of opposed curved walls spaced apart a major dimension with the area between the major con-: striction and the minor constriction being smooth, curved . tapering wall surfaces tapering i.nwardly in the line of :,. . .
- circumference of the wheel for compressing the filament to in-;. crease the density thereof adjacent the minor constriction for ~ 20 locking the filament and wheel in relation to each other when . the load is transmitted therebetween.
.. Figure 1 is a side elevational vi.ew, with portions broken away, illustrating the present invention.
Figure 2 is an edge view of the positive drive wheel.
Figure 3 is a sectional view, on an enlarged scale, ;
:; taken substantially upon a plane passing along section line 3-3 of Figure 1.
Figure 4 is a sectional view, on an enlarged scale, taken substanti.ally upon a plane passing along section line 4-4 of Figure 1, .
. Figure 5 is a developed section of the wall surface . of one cycle of the periphery of the positive drive element ~ .
: illustrating the tapering construction of the semi-frustoconical br/ :\ ~
- - 10669Zl grooves or impressions.
The positive drive power transmission element of the present invention is in the form of a generally circular wheel ~: designated by reference numeral 10 and including a central aperture 12 for mounting on a shaft or axle with the aperture 12 including a keyway 14 communicated therewith to receive a ; key for locking the wheel 10 to a shaft or axle for rotation therewith so that power may be transmitted from the wheel to the axle or from the axle to the wheel in a positive manner.
Engaged with the wheel 10 is a flexible compressible filament -; 16 which, for the purposes of description, will be considered ':
~ .
:
. ' ;
~ . . .
:' ' , , :', . 1 ~'`" '.
.` :~
.. . .
,; :
-2a-.~ ~ cbr/~;s~
, ~0669Zl a rope although other equivalent types of flexible co~pressible filaments may be employed. As illustrated, the wheel 10 is constructed of two plates 18 and 20 which are secured rigidly together in face to face relationship by a plural~
ity of screw threaded fasteners 22 which may be conveniently countersunk into one plate and screw threaded into the other and terminating flush therewith thus providing flat surfaces on the wheel 10.
As illustrated in the drawings, the peripheral edge of the plate 18 is provided with an inclined bevel 24 and the peripheral edge of the plate 20 is provided with a similar inclined bevel 26 around the periphery thereof so that the beveled surfaces or inclined surfaces 24 and 26 coact with each other when the plates 18 and 20 are secured together to form a generally V-shaped peripheral groove or recess in the wheel which may be considered similar to a V-shaped groove in the periphery of the sheave of a V-belt drive pulley.
The wheel 10 has a unique and novel peripheral structure disposed at the inner edge of the beveled or inclined surfaces 24 and 26 with the peripheral surface having a peripheral groove defined therein by an offset shoulder 28 on one of the plates, as illustrated in Figures 3 and 4. The groove has two walls ., ; which are opposed to each other outwsrdly of the peripheral shoulder 28 in which each groove wall is of identical construction and includes six depressions or im-20 pressions along the line of circumference of the walls. Each impression or de-? pression is generally designated by numeral 30 and include a ms~or width area 32 and a minor width area 34 with the impression 30 including semi-frustoconical tapering surface areas 36 in each wall. As illustrated, ~ix cycles or impres-sions are provided in the periphery of the wheel 10 with each cycle including a continuous bottom wall defined by the shoulder 28 and the two walls of the groove tapering along the line of circumference of the wheel from a ma~or spaced rela-tion to a minor spaced relation in which the ma~or spaced relation is designated by numeral 32 and the minor spaced relation 34 is spaced therefrom with the walls between the ma~or and minor spaced relationships tapering inwardly as ~ 30 indicated by numeral 36 to generally form a semi-frustoconical configuration i with the walls at the minor dimension 34 being substantially parallel and op-posed as illustrated in Figure 3 and the wall~ at other places being curved as indicated in Figure 4. This tapering construction of the walls of the impres-~3~
~L{)66921 sions 30 provides for compression of the rope 16 30 that the density of the rope engaging the tapering surfaces 36 opposed to the application of the load to the rope will sec~rely lock the rope to the wheel 10 in a manner that will prevent slippage.
In one practical embodiment of the invention which has been succes~-fully tes~ed, a 9-inch diameter wheel was provided with the two plates being ~oined together with the width of the shoulder 28 being 1/8 inch so that the minor transverse dimension or constriction 34 is 1/8 inch wide and the major ` dimension at 32 is 3/8 inch wide and the developed linear distance between point 32 and point 34 in Figure 5 is two inches. The dimensional character-istics may vary insofar as the diameter of the wheel and thickness of the wheel i6 concerned but the ratio of the minor dimension or constriction and the major dimension or constriction should remain approximately a one to two or three ratio for compression of common rope with the taper from the maximum constriction at point 32 to the minor constriction at point 34 being smooth and straight with the walls being curved to approximate a semi-frustoconical shape although the , wall surfaces will define a cycloidal transition from the walls at point 34 to ; the curved walls at a point approaching point 32.
The construction of the wheel will transmit power between the wheel and rope, round belt, cable or the like without slippage with the compression of the rope preventing slippage rather than friction which occurs in most pulley and rope drives. The compression locking flction is the function of the semi-frustoconical impressions 30 in each wall of the tapered groove. The equally spaced semi-frustoconlcal impressions mesh with the round belt, rope or cable with the tapering construction of the opposed pairs of impressions compressing the round belt, rope or cable and increasing the density thereof thus positively connecting the round belt, rope or cable to the wheel. In the test model of the invention dimensioned as set forth above, a 5/16 inch diameter solid braided nylon rope was employed with the rope or cord positioned onto the wheel with a tail length of the cord hanging toward the floor and the other end of the cord was connected to a losd of 1000 pounds and torque exerted on the wheel in a direction to lift the load. When the nylon cord had been stretched to near breaking point, the apparatus was stopped and it was noted that the cord had .
:. .
~0669Zl not and did not slip even though tangentially held by only one tapered groove in the periphery of the wheel and the tail length of the nylon cord was hanging free and completely slack while the portion of the cord running through the load is stretched out to near its breaking point.
Even though the walls of the semi-frustoconical impressions are smooth surfaces and do not provide any substantial coefficient of friction, slippage - was eliminated by virtue of compression of the rope with the compression of the rope increasing the density thereof with the rope being locked with a resistance equal to an infinite load as the load is applied. Thus, the wheel of this invention does not reduce or retard slippage through friction since it does not incorporate friction in the working principle. The substantially semi-frusto-conical impressions in which the taper is in the direction or line of circum-ference provides the mechanical function of locking the rope to the wheel in a pobitive relationship for transferring driving force therebetween.
~''
Transmission of power by using a flexible power trans-mitting element engaged with a pulley rotatable about an axle has been used for many years and has included pulleys with flat surfaces for engaging flat drive belts, pulleys with a V-shaped groove for engaging V belts and similar types of structures in which friction between the pulley and flexible element serves to transmit power and to perform work. Various efforts have :, .. .
~ been made to modify rope pulleys to increase the frictional ; engagement between the rope and pulley but such devices usually employ radial converging surfaces, such as ribs or lugs, on the radially converging surfaces of the pulley groove which increase friction but even so~ slippage will occur between the : .
~ rope and pulley when a sufficient load iB encountered when the ,~ compressed diameter of the rope or cable i8 insertable in the ; narrowest construction of the walls of the pulley or sheave.
~; An ob;ect of the invention is to provlde a positive drive element for the transmission of power between a com-pressible filament such as a rope and a wheel having a uniquely ; constructed peripheral groove in which slippage is eliminated by compression of the filament or rope.
A still further object of the invention is to provide a positive drive transmission element which is quite simple in . .
construction, easy to utilize in various power transmission , .: --1--"~ , - ~ .b~/~XY~ ~ ~
1~6~;9Z~
` ~
: arrangements and efficient in positive transfer of driving force.
; The present invention provides a positive drive power transmission element comprising a generally circular wheel ~ .
adapted to be rigidly connected to an axle for rotational ::
: movement about an axle, the wheel including a peripheral groo~e .~ -receiving a flexible, compressible filament and means incor- .
porated into the groove to provide a positive driving connection ..
between the wheel and filament, the means including a plurality ~ --of equally spaced circumferentially extending semi-frustoconical . impressions in each wall of the groove, the impressions being :: arranged in pairs including a minor constriction area having .
: wall portions spaced apart a minimum distance and a major constriction area having a pair of opposed curved walls spaced apart a major dimension with the area between the major con-: striction and the minor constriction being smooth, curved . tapering wall surfaces tapering i.nwardly in the line of :,. . .
- circumference of the wheel for compressing the filament to in-;. crease the density thereof adjacent the minor constriction for ~ 20 locking the filament and wheel in relation to each other when . the load is transmitted therebetween.
.. Figure 1 is a side elevational vi.ew, with portions broken away, illustrating the present invention.
Figure 2 is an edge view of the positive drive wheel.
Figure 3 is a sectional view, on an enlarged scale, ;
:; taken substantially upon a plane passing along section line 3-3 of Figure 1.
Figure 4 is a sectional view, on an enlarged scale, taken substanti.ally upon a plane passing along section line 4-4 of Figure 1, .
. Figure 5 is a developed section of the wall surface . of one cycle of the periphery of the positive drive element ~ .
: illustrating the tapering construction of the semi-frustoconical br/ :\ ~
- - 10669Zl grooves or impressions.
The positive drive power transmission element of the present invention is in the form of a generally circular wheel ~: designated by reference numeral 10 and including a central aperture 12 for mounting on a shaft or axle with the aperture 12 including a keyway 14 communicated therewith to receive a ; key for locking the wheel 10 to a shaft or axle for rotation therewith so that power may be transmitted from the wheel to the axle or from the axle to the wheel in a positive manner.
Engaged with the wheel 10 is a flexible compressible filament -; 16 which, for the purposes of description, will be considered ':
~ .
:
. ' ;
~ . . .
:' ' , , :', . 1 ~'`" '.
.` :~
.. . .
,; :
-2a-.~ ~ cbr/~;s~
, ~0669Zl a rope although other equivalent types of flexible co~pressible filaments may be employed. As illustrated, the wheel 10 is constructed of two plates 18 and 20 which are secured rigidly together in face to face relationship by a plural~
ity of screw threaded fasteners 22 which may be conveniently countersunk into one plate and screw threaded into the other and terminating flush therewith thus providing flat surfaces on the wheel 10.
As illustrated in the drawings, the peripheral edge of the plate 18 is provided with an inclined bevel 24 and the peripheral edge of the plate 20 is provided with a similar inclined bevel 26 around the periphery thereof so that the beveled surfaces or inclined surfaces 24 and 26 coact with each other when the plates 18 and 20 are secured together to form a generally V-shaped peripheral groove or recess in the wheel which may be considered similar to a V-shaped groove in the periphery of the sheave of a V-belt drive pulley.
The wheel 10 has a unique and novel peripheral structure disposed at the inner edge of the beveled or inclined surfaces 24 and 26 with the peripheral surface having a peripheral groove defined therein by an offset shoulder 28 on one of the plates, as illustrated in Figures 3 and 4. The groove has two walls ., ; which are opposed to each other outwsrdly of the peripheral shoulder 28 in which each groove wall is of identical construction and includes six depressions or im-20 pressions along the line of circumference of the walls. Each impression or de-? pression is generally designated by numeral 30 and include a ms~or width area 32 and a minor width area 34 with the impression 30 including semi-frustoconical tapering surface areas 36 in each wall. As illustrated, ~ix cycles or impres-sions are provided in the periphery of the wheel 10 with each cycle including a continuous bottom wall defined by the shoulder 28 and the two walls of the groove tapering along the line of circumference of the wheel from a ma~or spaced rela-tion to a minor spaced relation in which the ma~or spaced relation is designated by numeral 32 and the minor spaced relation 34 is spaced therefrom with the walls between the ma~or and minor spaced relationships tapering inwardly as ~ 30 indicated by numeral 36 to generally form a semi-frustoconical configuration i with the walls at the minor dimension 34 being substantially parallel and op-posed as illustrated in Figure 3 and the wall~ at other places being curved as indicated in Figure 4. This tapering construction of the walls of the impres-~3~
~L{)66921 sions 30 provides for compression of the rope 16 30 that the density of the rope engaging the tapering surfaces 36 opposed to the application of the load to the rope will sec~rely lock the rope to the wheel 10 in a manner that will prevent slippage.
In one practical embodiment of the invention which has been succes~-fully tes~ed, a 9-inch diameter wheel was provided with the two plates being ~oined together with the width of the shoulder 28 being 1/8 inch so that the minor transverse dimension or constriction 34 is 1/8 inch wide and the major ` dimension at 32 is 3/8 inch wide and the developed linear distance between point 32 and point 34 in Figure 5 is two inches. The dimensional character-istics may vary insofar as the diameter of the wheel and thickness of the wheel i6 concerned but the ratio of the minor dimension or constriction and the major dimension or constriction should remain approximately a one to two or three ratio for compression of common rope with the taper from the maximum constriction at point 32 to the minor constriction at point 34 being smooth and straight with the walls being curved to approximate a semi-frustoconical shape although the , wall surfaces will define a cycloidal transition from the walls at point 34 to ; the curved walls at a point approaching point 32.
The construction of the wheel will transmit power between the wheel and rope, round belt, cable or the like without slippage with the compression of the rope preventing slippage rather than friction which occurs in most pulley and rope drives. The compression locking flction is the function of the semi-frustoconical impressions 30 in each wall of the tapered groove. The equally spaced semi-frustoconlcal impressions mesh with the round belt, rope or cable with the tapering construction of the opposed pairs of impressions compressing the round belt, rope or cable and increasing the density thereof thus positively connecting the round belt, rope or cable to the wheel. In the test model of the invention dimensioned as set forth above, a 5/16 inch diameter solid braided nylon rope was employed with the rope or cord positioned onto the wheel with a tail length of the cord hanging toward the floor and the other end of the cord was connected to a losd of 1000 pounds and torque exerted on the wheel in a direction to lift the load. When the nylon cord had been stretched to near breaking point, the apparatus was stopped and it was noted that the cord had .
:. .
~0669Zl not and did not slip even though tangentially held by only one tapered groove in the periphery of the wheel and the tail length of the nylon cord was hanging free and completely slack while the portion of the cord running through the load is stretched out to near its breaking point.
Even though the walls of the semi-frustoconical impressions are smooth surfaces and do not provide any substantial coefficient of friction, slippage - was eliminated by virtue of compression of the rope with the compression of the rope increasing the density thereof with the rope being locked with a resistance equal to an infinite load as the load is applied. Thus, the wheel of this invention does not reduce or retard slippage through friction since it does not incorporate friction in the working principle. The substantially semi-frusto-conical impressions in which the taper is in the direction or line of circum-ference provides the mechanical function of locking the rope to the wheel in a pobitive relationship for transferring driving force therebetween.
~''
Claims (10)
1. A positive drive power transmission element comprising a general-ly circular wheel adapted to be rigidly connected to an axle for rotational movement about an axle, said wheel including a peripheral groove receiving a flexible, compressible filament and means incorporated into the groove to pro-vide a positive driving connection between the wheel and filament, said means including a plurality of equally spaced circumferentially extending semi-frustoconical impressions in each wall of the groove, said impressions being arranged in pairs including a minor constriction area having wall portions spaced apart a minimum distance and a major constriction area having a pair of opposed curved walls spaced apart a major dimension with the area between the major constriction and the minor constriction being smooth, curved tapering wall surfaces tapering inwardly in the line of circumference of the wheel for compressing the filament to increase the density thereof adjacent the minor constriction for locking the filament and wheel in relation to each other when the load is transmitted therebetween.
2. The structure as defined in claim 1 wherein the transverse dimen-sion of the minor constriction is substantially less than the transverse dimen-sion of the major constriction for locking engagement of the wheel and filament without increasing frictional resistance.
3. The structure as defined in claim 1 wherein the transverse dimen-sion of the minor constriction is approximately 1/3 of the transverse dimension of the major constriction.
4. The structure as defined in claim 1 wherein said filament is in the form of a flexible rope, belt or cable having a generally circular trans-verse cross section.
5. The structure as defined in claim 1 wherein said wheel includes six equally spaced impressions with the impressions being continuously arranged around the periphery of the wheel with the groove having a bottom width equal to the transverse dimension of the minor constriction.
6. The structure as defined in claim 1 wherein said groove in the periphery of the wheel includes a pair of outwardly diverging inclined surfaces extending from the outer edge of the groove to the peripheral edges of the wheel defining a generally V-shaped recess in the periphery of the wheel com-municating with the groove to enable the filament to be positioned in the groove.
7. The structure as defined in claim 6 wherein said filament is a flexible rope, belt or cable having a circular transverse cross section, said wheel including six equally spaced impressions around the periphery thereof with the transverse dimension of the minor constriction being approximately 1/3 the transverse dimension of the major construction.
8. A positive three dimensional constraint device comprising a member having a groove receiving a flexible, compressible filament and means incorpo-rated into the groove to provide a positive connection between the groove and filament, said means including a longitudinally extending semi-frustoconical impression in each wall of the groove, said impressions being arranged in op-posed relation to define a minor constriction area having wall portions spaced apart a minimum distance and a major constriction area having a pair of opposed curved walls spaced apart a major dimension with the area between the major construction and the minor constriction being smooth, curved tapering wall surfaces tapering inwardly in one longitudinal direction for compressing the filament to increase the density thereof adjacent the minor constriction for locking the filament and groove in relation to each other when a load is exerted to cause relative movement between the filament and member in said longitudinal direction, said minor constriction enabling engagement between the filament and member in a transverse direction inwardly and outwardly of the groove without increase in frictional resistance due to the longitudinal load.
9. A drive power transmission element comprising a generally circu-lar wheel adapted to be rigidly connected to an axle for rotational movement about an axis, said wheel including a generally V-shaped peripheral recess defined by a pair of radially outwardly diverging smooth surfaces terminating at the periphery of the wheel, the radially inner periphery of the recess having a radially extending peripheral groove communicating therewith for receiving a flexible, compressible filament, said groove being defined by a pair of spaced walls and an inner shoulder concentric with the periphery of the wheel and means incorporated into the groove to provide a driving connec-tion between the wheel and filament, said means including a plurality of equal-ly spaced circumferentially extending impressions in each wall of the groove, said impressions being arranged in aligned pairs including a minor construction area having wall portions spaced apart a minimum distance and a major constric-tion area having a pair of opposed curved walls spaced apart a major dimension with the area between the major constriction and the minor constriction being defined by opposed, smooth, radially curved wall surfaces curving circumfer-entially inwardly in the line of circumference of the wheel toward the minor constriction area for compressing the filament to increase the density thereof adjacent the minor constriction area for locking the filament and wheel in relation to each other when a load is transmitted therebetween.
10. The structure as defined in claim 9 wherein the transverse dimension of the minor constriction is approximately 1/3 of the transverse dimension of the major constriction, said walls including six equally spaced pairs of impressions with the impressions being continuously arranged around the periphery of the wheel, said groove having a bottom width equal to the transverse dimension of the minor constriction with the walls at the minor constriction area being substantially radially parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA288,520A CA1066921A (en) | 1977-10-12 | 1977-10-12 | Drive power transmission element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA288,520A CA1066921A (en) | 1977-10-12 | 1977-10-12 | Drive power transmission element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1066921A true CA1066921A (en) | 1979-11-27 |
Family
ID=4109746
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA288,520A Expired CA1066921A (en) | 1977-10-12 | 1977-10-12 | Drive power transmission element |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1066921A (en) |
-
1977
- 1977-10-12 CA CA288,520A patent/CA1066921A/en not_active Expired
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