US3811332A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic tensioning device
Assignee: FMC Corp
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Filing: 1972-08-22
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Granted: 1974-05-21
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Expires: 1992-08-22
Abstract
Abstract A dual tensioning device is provided to take up the slack on an endless belt or chain regardless of the direction of drive. A pair of arms are pivoted at a common point outside the loop defined by the endless belt or chain. Each arm has a friction pad pivotally mounted at the outer end, and the ends of the arms, which are of unequal length, are connected by a tension spring. The longitudinal axis of the spring is inclined at different angles to the arms when the endless belt or chain is driven in a normal operating direction so that a greater tensioning force is applied to the slack side of the belt or chain.
Inventors
- 👤 M Brown
- 👤 S Avramidis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:21
CPC Classifications
F; F16; F16H; F16H7/00; F16H7/08; F16H2007/0863; F16H2007/0874; F16H2007/0889; F16H2007/0893; F16H7/0829
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
275 words
A dual tensioning device to operate on the tension and slack sides of a reversible endless flexible drive member received on members rotatable about spaced apart axes, the combination comprising a frame, a first arm pivotally mounted on a pivot point on the frame spaced from said axes and located outside of the path of the endless flexible member, said first arm having means thereon to engage one side of the flexible drive member which is under tension when the drive member is running in a normal operating direction, a second arm pivotally mounted at said pivot point on the frame and having means thereon to engage the other side of the flexible drive member which is slack when the drive member is running in a normal operating direction, a spring connected to said first arm at a first point and connected to said second arm at a second point to create equal and opposite forces on said arms along the longitudinal axis of said spring and between the points where the spring is connected to the arms, said first and second spring connection points located at positions on said arms where the axis of the spring makes a smaller angle with said first arm than with said second arm when said one side of the drive member is under tension and running in its normal operating direction, whereby a component of force perpendicular to the axis of the second arm and exerted Against the slack side of the flexible drive member is greater than the component of force perpendicular to the first arm and exerted against the tension side of the flexible drive member.
Claim 2
Dependent Claim
275 words
A dual tensioning device to operate on the tension and slack sides of a reversible endless flexible drive member received on members rotatable about spaced apart axes, the combination comprising a frame, a first arm pivotally mounted on a pivot point on the frame spaced from said axes and located outside of the path of the endless flexible member, said first arm having means thereon to engage one side of the flexible drive member which is under tension when the drive member is running in a normal operating direction, a second arm pivotally mounted at said pivot point on the frame and having means thereon to engage the other side of the flexible drive member which is slack when the drive member is running in a normal operating direction, a spring connected to said first arm at a first point and connected to said second arm at a second point to create equal and opposite forces on said arms along the longitudinal axis of said spring and between the points where the spring is connected to the arms, said first and second spring connection points located at positions on said arms where the axis of the spring makes a smaller angle with said first arm than with said second arm when said one side of the drive member is under tension and running in its normal operating direction, whereby a component of force perpendicular to the axis of the second arm and exerted Against the slack side of the flexible drive member is greater than the component of force perpendicular to the first arm and exerted against the tension side of the flexible drive member.
Claim 3
Dependent Claim
42 words
The dual tensioning device of claim 1 in which said arms pivot to accommodate the new path of the flexible drive member when the direction of drive member operation is reversed to reverse the tension and slack sides of the drive member.
Claim 4
Dependent Claim
25 words
The dual tensioning device of claim 1 in which said means on the arms to engage the sides of the flexible drive member are pads.
Claim 5
Dependent Claim
28 words
The dual tensioning device of claim 3 in which said pads are pivotally mounted on the arms and are contoured to accommodate the slack side of the chain.
Claim 6
Dependent Claim
197 words
A dual tensioning device to operate on the tension and slack side of an endless flexible drive member received on members rotatable about spaced apart axes, the combination comprising a frame, a first arm pivotally mounted at a pivot point on the frame spaced from said aces, said first arm having means thereon to engage the one side of the flexible drive member which is under tension when the drive member is running in a normal operating direction, a second arm pivotally mounted at said pivot point on the frame and having means thereon to engage the other side of the flexible drive member which is slack when the drive member is running in a normal operating direction, said arms being of different length, a spring connected between the ends of said arms to create equal and opposite forces on said arms along the longitudinal axis of said spring, said spring axis forming a smaller angle with said first arm than with said second arm when said one side of the drive member is under tension whereby a greater force is exerted against the slack side of the flexible drive member than against the tension side thereof.
Claim 7
Dependent Claim
197 words
A dual tensioning device to operate on the tension and slack side of an endless flexible drive member received on members rotatable about spaced apart axes, the combination comprising a frame, a first arm pivotally mounted at a pivot point on the frame spaced from said aces, said first arm having means thereon to engage the one side of the flexible drive member which is under tension when the drive member is running in a normal operating direction, a second arm pivotally mounted at said pivot point on the frame and having means thereon to engage the other side of the flexible drive member which is slack when the drive member is running in a normal operating direction, said arms being of different length, a spring connected between the ends of said arms to create equal and opposite forces on said arms along the longitudinal axis of said spring, said spring axis forming a smaller angle with said first arm than with said second arm when said one side of the drive member is under tension whereby a greater force is exerted against the slack side of the flexible drive member than against the tension side thereof.
Claim 8
Dependent Claim
272 words
A dual tensioning device to operate on the tension and slack sides of a reversible endless flexible drive member received on members rotatable about spaced apart axes, the combination comprising a frame, a first arm pivotally mounted on a pivot point on the frame spaced from said axes and located outside of the path of the endless flexible drive member, said first arm having means thereon to engage one side of the flexible drive member which is under tension when the drive member is running in a normal operating direction, a second arm pivotally mounted at said pivot point on the frame and having means thereon to engage the other side of the flexible drive member which is slack when the drive member is running in a normal operating direction, a spring connected to said first arm at a first spring connection point and connected to said second arm at a second spring connection point to create equal and opposite forces on said arms along the longitudinal axis of said spring and between said spring connection points, said first and second spring connection points located at positions spaced different distances from said pivot point to form a smaller angle between said spring axis and said first arm when said one side of the drive member is under tension and running in its normal operating direction, whereby a component of force perpendicular to the axis of the second arm and exerted against the slack side of the flexible drive member is greater than the component of force perpendicular to the first arm and exerted against the tension side of the flexible drive member.
Claim 9
Dependent Claim
272 words
A dual tensioning device to operate on the tension and slack sides of a reversible endless flexible drive member received on members rotatable about spaced apart axes, the combination comprising a frame, a first arm pivotally mounted on a pivot point on the frame spaced from said axes and located outside of the path of the endless flexible drive member, said first arm having means thereon to engage one side of the flexible drive member which is under tension when the drive member is running in a normal operating direction, a second arm pivotally mounted at said pivot point on the frame and having means thereon to engage the other side of the flexible drive member which is slack when the drive member is running in a normal operating direction, a spring connected to said first arm at a first spring connection point and connected to said second arm at a second spring connection point to create equal and opposite forces on said arms along the longitudinal axis of said spring and between said spring connection points, said first and second spring connection points located at positions spaced different distances from said pivot point to form a smaller angle between said spring axis and said first arm when said one side of the drive member is under tension and running in its normal operating direction, whereby a component of force perpendicular to the axis of the second arm and exerted against the slack side of the flexible drive member is greater than the component of force perpendicular to the first arm and exerted against the tension side of the flexible drive member.
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |