US3756091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positive power transmission system
Assignee: Gates Rubber Co
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Filing: 1970-02-19
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Granted: 1973-09-04
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Expires: 1990-02-19
Abstract
Abstract A toothed power transmission belt and pulley system is disclosed wherein the belt has an endless substantially inextensible tensile member with teeth secured thereto, the teeth having a cross-sectional configuration composed of two circular intersecting arcs for meshing with mating, conjugate, curvilinear pulley teeth. The size of teeth, length of radii of curvature, and the angles and point of intersection are determined by a set of design criteria and formulas as recited herein.
Inventors
- 👤 H Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:50
CPC Classifications
F; F16; F16G; F16G1/00; F16G1/28; B; B62; B62D; B62D55/00; B62D55/08; B62D55/12; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19949; Y10T74/19963; Y10T74/19972
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
58 words
A positive drive system comprising: a flexible belt having a tensile member; curvilinear teeth secured to said tensile member and at least one pulley having mating substantially conjugate teeth wherein said belt teeth have a longitudinal cross-sectional contour which approximates the contour of the 1/2 order isochromatic fringe in the belt when said tooth is under rated load.
Claim 2
Dependent Claim
58 words
A positive drive system comprising: a flexible belt having a tensile member; curvilinear teeth secured to said tensile member and at least one pulley having mating substantially conjugate teeth wherein said belt teeth have a longitudinal cross-sectional contour which approximates the contour of the 1/2 order isochromatic fringe in the belt when said tooth is under rated load.
Claim 3
Dependent Claim
56 words
A positive drive system according to claim 1 wherein said pulley and belt teeth are of such dimensions that within a belt tooth which is under rated load and in contact with a mating pulley tooth, the isochromatic fringes are located substantially parallel to the tensile member in the region immediately adjacent to the tensile member.
Claim 4
Dependent Claim
61 words
A positive drive system according to claim 1 wherein said pulley and belt teeth are of such dimensions that within a belt tooth which is under rated load and in contact with a mating pulley the isochromatic fringe order across the belt tooth along a line joining the tips of adjacent pulley teeth does not vary by more than four fringes.
Claim 5
Dependent Claim
60 words
A positive drive system according to claim 1 wherein said pulley and belt teeth are of such dimensions that withiN a belt tooth which is under rated load and in contact with a mating pulley tooth, the principal strains throughout at least seventy five percent of the longitudinal cross-sectional area of the belt tooth are in substantially the same direction.
Claim 6
Dependent Claim
74 words
A positive drive system according to claim 1 wherein said pulley and belt teeth are of such dimensions that within a belt tooth which is under rated load and in contact with a mating pulley tooth the value of the shear strain in a direction along a line joining the tips of adjacent pulley teeth for all points in the belt tooth along the said line varies by less than a factor of five.
Claim 7
Dependent Claim
83 words
A positive drive power transmission belt comprising: a flexible belt having a tensile member; elastomeric teeth of constant longitudinal cross-section secured to said tensile member; the longitudinal cross-sectional contour of the portion of each belt tooth farthest away from the tensile member being composed of two intersecting substantially circular arcs of equal radius, the height of the portion of each tooth within the confines of said arcs being at least sixty percent of the total tooth height as measured from said tensile member.
Claim 8
Dependent Claim
83 words
A positive drive power transmission belt comprising: a flexible belt having a tensile member; elastomeric teeth of constant longitudinal cross-section secured to said tensile member; the longitudinal cross-sectional contour of the portion of each belt tooth farthest away from the tensile member being composed of two intersecting substantially circular arcs of equal radius, the height of the portion of each tooth within the confines of said arcs being at least sixty percent of the total tooth height as measured from said tensile member.
Claim 9
Dependent Claim
33 words
A power transmission belt according to claim 6 wherein the circular arcs of the belt teeth join with the arcs of adjacent teeth at points near the outer edge of said tensile member.
Claim 10
Dependent Claim
41 words
The power transmission belt of claim 6 wherein the said longitudinal cross-sectional contour of the belt tooth composed of two circular arcs approximates the contour of the 1/2 order isochromatic fringe in said tooth when said belt is under rated load.
Claim 11
Dependent Claim
77 words
A positive drive system comprising in combination a power transmission belt according to claim 6 and at least one pulley having mating, substantially conjugate teeth wherein the dimension of said belt and pulley teeth are such that within a belt tooth which is under its rated load and which is in contact with a mating pulley tooth the isochromatic fringes are oriented substantially parallel to the tensile member in the region immediately adjacent to the tensile member.
Claim 12
Dependent Claim
87 words
A positive drive system comprising in combination a power transmission belt according to claim 6 and at least one pulley having mating, substantially conjugate teeth wherein the dimensions of said belt and pulley teeth are such that within a belt tooth which is under rated load and which is in contact with a mating pulley the change in the isochromatic fringe order across the width of said belt tooth on a line joining the tips of adjacent pulley teeth, does not vary by more than four fringes.
Claim 13
Dependent Claim
80 words
A positive drive system comprising in combination a power transmission belt according to claim 6 and at least one pulley having mating, substantially conjugate teeth wherein the dimensions of said belt and pulley teeth are such that within a belt tooth which is under rated load and which is in contact with a mating pulley tooth, the principal strains throughout at least seventy five percent of the longitudinal cross-sectional area of said belt tooth are in substantially the same direction.
Claim 14
Dependent Claim
94 words
A positive drive system comprising in combination a power transmission belt according to claim 6 and at least one pulley having mating, substantially conjugate teeth wherein the dimensions of said belt and pulley teeth are such that within a belt tooth which is under rated load and which is in contact with a mating pulley tooth the value of the shear strain in a direction along a line joining the tips of adjacent pulley teeth for all points in the belt tooth along the said line varies by less than a factor of five.
Claim 15
Dependent Claim
53 words
A power transmission belt according to claim 6 wherein the belt tooth has roots with a longitudinal cross-sectional contour composed of substantially circular arcs having their centers of curvature outside of the belt tooth on a line parallel to the tensile member of said belt tooth when said tensile member is linearly positioned.
Claim 16
Dependent Claim
54 words
A power transmission belt according to claim 6 wHerein each belt tooth has roots with a longitudinal cross-sectional contour composed of a substantially circular arc having its center of curvature located on the same line as the centers of curvature of the arcs which form the belt teeth when the belt is linearly positioned.
Claim 17
Dependent Claim
63 words
A power transmission belt according to claim 6 wherein each belt tooth has roots with a longitudinal cross-sectional contour composed of substantially circular arcs having their centers of curvature located on a line which is closer to the tensile member than a line that contains the centers of curvature of the arcs which form the belt tooth when the belt is linearly positioned.
Claim 18
Dependent Claim
48 words
A power transmission belt according to claim 15 wherein the ends of the belt teeth roots of adjacent belt teeth closest to the tensile member are joined by a land portion the edge of which is parallel to the tensile member when the tensile member is linearly positioned.
Claim 19
Dependent Claim
41 words
A power transmission belt according to claim 16 wherein the belt teeth are covered by a protective jacket and there is a layer of elastomeric material between the tension member and the jacket in the land area between the belt teeth.
Claim 20
Dependent Claim
88 words
A power transmission belt according to claim 6 wherein the belt teeth are covered by a protective jacket, said jacket having its splices cut on a bias such that each splice makes a minimum angle with the belt tooth such that if the splice starts at the point where one of the belt tooth roots blends with its land area the closest point that it will end is at the point on the other side of the tooth where the tooth''s other root blends with its land area.
Claim 21
Dependent Claim
52 words
A power transmission belt according to claim 6 wherein the radii of curvature of the two substantially circular arcs are displaced from each other along a line parallel to the tensile member when said tensile member is linearly positioned by a distance not more than 20% of the length of said radii.
Claim 22
Dependent Claim
44 words
A power transmission belt according to claim 6 wherein the circular arcs of equal radius meet at a point and have centers of curvature displaced from each other on a line substantially parallel to said tensile member when said tensile member is linearly positioned.
Claim 23
Dependent Claim
73 words
A positive drive system comprising in combination a power transmission belt according to claim 6 and at least one pulley having mating, substantially conjugate teeth wherein said pulley teeth have tips, each tooth tip having longitudinal cross-sectional contours at least partially composed of two substantially circular arcs wherein said arcs have centers of curvature displaced from each other; and cavity portions composed of substantially circular arcs connecting the tips of adjacent pulley teeth.
Claim 24
Dependent Claim
44 words
The positive drive of claim 21 wherein the centers of curvature of said pulley teeth tips and said cavities are located on arcs which are radially displaced from and concentric with a circle connecting the outermost portion of the tips of the pulley teeth.
Claim 25
Dependent Claim
88 words
The positive drive of claim 22 wherein the radius of curvature of a pulley tooth, at any given point of contact with a belt tooth, is larger than the radius of curvature of a belt tooth at that point by an amount equal to or less than 10 percent of the belt tooth radius, and the center of curvature of the pulley tooth at any given point of contact is on the same side of the line of contact as the center of curvature of the belt tooth.
Claim 26
Dependent Claim
70 words
The positive drive of claim 22 wherein each belt tooth has roots with a curvilinear longitudinal contour and wherein a line drawn tangent to the outer edge of a belt tooth root at the point where the tooth root blends into said circular arcs which comprise the body of the tooth, makes an angle of less than 30* to a radial line running through the center of the tooth body.
Claim 27
Dependent Claim
51 words
The positive drive of claim 22 wherein a line drawn tangent to the edge of a pulley tooth at the point where the tip of the tooth blends into the body of said pulley tooth, makes an angle of lEss than 30* with the center line of the pulley tooth cavity.
Claim 28
Dependent Claim
45 words
The positive drive of claim 22 wherein each belt tooth has roots with a longitudinal cross-sectional contour composed of a circular arc and wherein the length of the radii of said root contour is less than 95% of the tip radii of the pulley teeth.
Claim 29
Dependent Claim
101 words
The positive drive of claim 26 wherein the distance across the belt tooth between the belt tooth roots which are closest to the tensile member, is approximately the distance given by the following equation: L (2T)/( pi SdcN) where L tooth width between roots of the same tooth required at the tensile member elastomer interface, T desired tensile capacity of belt, d tensile member diameter, c number of tensile members/unit length of belt width, N minimum number of belt teeth in contact with the pulley, S maximum shear stress that can be developed at the belt tooth-tensile member interface before separation.
Claim 30
Dependent Claim
42 words
The positive drive of claim 22 wherein the clearance between the outer tip of the belt tooth and said pulley cavity is not more than 10 percent of the distance between the pulley tip and the innermost point of the pulley cavity.
Claim 31
Dependent Claim
81 words
A positive drive power transmission belt comprising: an endless tensile member, and elastomer teeth of constant longitudinal cross-section secured to said tensile member, wherein the said longitudinal cross-sectional contour of the belt teeth is substantially that of a circular arc and the center of curvature of said arc is spaced from the center of the next tooth by a distance equal to or less than twice the radius of curvature of a belt tooth when said tensile member is linearly positioned.
Claim 32
Dependent Claim
81 words
A positive drive power transmission belt comprising: an endless tensile member, and elastomer teeth of constant longitudinal cross-section secured to said tensile member, wherein the said longitudinal cross-sectional contour of the belt teeth is substantially that of a circular arc and the center of curvature of said arc is spaced from the center of the next tooth by a distance equal to or less than twice the radius of curvature of a belt tooth when said tensile member is linearly positioned.
Claim 33
Dependent Claim
53 words
A positive drive comprising in combination a power transmission belt according to claim 29 and at least one pulley having mating substantially conjugate teeth wherein the longitudinal cross-section contour of the pulley teeth is formed by the intersection of substantially circular arcs having their centers of curvature outside the body of the pulley.
Claim 34
Dependent Claim
81 words
The positive drive of claim 29 wherein the belt teeth are covered by a protective jacket, said jacket having splices cut on a bias such that each splice makes a minimum angle with the belt such that if the splice starts at the point where one of the belt teeth intersect an adjacent belt tooth, the closest point that it will end is the point on the other side of the tooth where the tooth intersects with the other belt tooth.
Claim 35
Dependent Claim
85 words
The positive drive of claim 30 wherein the radius of curvature of a pulley tooth at any given point of contact with a belt tooth is longer than the radius of curvature of a belt tooth by an amount equal to or less than 10 percent of the belt tooth radius and the center of curvature of the pulley tooth at any given point of contact is on the same side of the line of contact as the center of curvature of the belt tooth.
Claim 36
Dependent Claim
50 words
The positive drive of claim 30 wherein a line drawn tangent to the belt tooth at the point where the tooth root blends into the main portion of the belt tooth makes an angle of less than 30* with the line of symmetry running through the center of the tooth.
Claim 37
Dependent Claim
90 words
The positive drive of claim 30 wherein the width of the belt tooth is approximately the distance given by the following equation: L (2T)/( pi SdcN) where L tooth width between roots of the same tooth required at the belt tooth tensile member interface, T desired tensile capacity of the belt, d tensile member diameter, c number of tensile members/unit length of belt width, N minimum number of belt teeth in contact with the pulley, S maximum shear stress that can be developed at belt tooth-tensile member interface befOre separation.
Claim 38
Dependent Claim
42 words
The positive drive of claim 30 wherein the clearance between the outer tip of the belt tooth and said pully cavity being not more than 10 percent of the distance between the pulley tip and the innermost point of the pulley cavity.
Claim 39
Dependent Claim
31 words
The positive drive of claim 30 wherein the longitudinal cross-sectional configuration of the belt tooth approximates the contour of the 1/2 order isochromatic fringe in said tooth when under rated load.
Claim 40
Dependent Claim
55 words
A toothed pulley for use in a positive drive system wherein the teeth have tips, each tip having a longitudinal cross-sectional contour at least partially composed of two substantially circular arcs, said arcs having centers of curvature displaced from each other and cavity portions composed of substantially circular arcs connecting the tips of adjacent teeth.
Claim 41
Dependent Claim
55 words
A toothed pulley for use in a positive drive system wherein the teeth have tips, each tip having a longitudinal cross-sectional contour at least partially composed of two substantially circular arcs, said arcs having centers of curvature displaced from each other and cavity portions composed of substantially circular arcs connecting the tips of adjacent teeth.
Claim 42
Dependent Claim
44 words
The toothed pulley of claim 37 wherein the centers of curvature of said pulley teeth tips and said cavities are located on arcs which are radially displaced from and concentric with a circle connecting the outermost portion of the tips of the pulley teeth.
Claim 43
Dependent Claim
40 words
A toothed pulley for use in a positive drive wherein the longitudinal cross-sectional contour of each of the pulley teeth is formed by the intersection of substantially circular arcs having their centers of curvature outside the body of the tooth.
Claim 44
Dependent Claim
40 words
A toothed pulley for use in a positive drive wherein the longitudinal cross-sectional contour of each of the pulley teeth is formed by the intersection of substantially circular arcs having their centers of curvature outside the body of the tooth.
Claim 45
Dependent Claim
38 words
A power transmission belt comprising: an endless tensile member and elastomer teeth of constant longitudinal cross-section secured to said tensile member, wherein the said longitudinal cross-sectional contour of the belt teeth is substantially that of a circular arc.
Claim 46
Dependent Claim
38 words
A power transmission belt comprising: an endless tensile member and elastomer teeth of constant longitudinal cross-section secured to said tensile member, wherein the said longitudinal cross-sectional contour of the belt teeth is substantially that of a circular arc.
Claim 47
Dependent Claim
36 words
The positive drive of claim 22 wherein the centers of curvature of each of the arcs partially forming the toothed pulley tooth tips are located on the same side of the tooth as its respective arc.
Claim 48
Dependent Claim
36 words
The positive drive of claim 37 wherein the centers of curvature of each of the arcs partially forming the toothed pulley tooth tips are located on the same side of the tooth as its respective arc.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |