US4681177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for tensioning frictionally driven, ground engaging belts
Assignee: Caterpillar Inc
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Filing: 1985-12-09
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Granted: 1987-07-21
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Expires: 2005-12-09
Abstract
Abstract Method and apparatus for tensioning an endless, inextensible, elastomeric ground engaging belt into frictional driven engagement with a driver wheel structure, oscillatably supporting an axle on which an idler wheel structure associated with the drive wheel structure is mounted, and accommodating recoil of the idler wheel structure. Such associated wheel structures are arranged on each lateral side of a vehicular main frame and are entrained by the ground engaging belt. The idler wheel structures are rotatably mounted on opposite ends of the axle extending laterally relative to the main frame. The axle is oscillatably mounted to the main frame about an oscillation axis parallel to the vehicle's longitudinal axis to accommodate uneven terrain and about a vertical axis to permit substantially independent recoil of the respective idler wheel structures. A pair of spring assemblies mounted on opposite lateral sides of the oscillation axis biasingly pull the axle in a direction away from the driver wheel structures to maintain the desired orientation of the axle about its laterally extending axis of rotation.
Inventors
- 👤 David G. Zborowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:14
CPC Classifications
B; B62; B62D; B62D55/00; B62D55/08; B62D55/30; B62D55/084
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
114 words
A belt laying work vehicle comprising: a main frame having a longitudinal axis; a laterally extending rigid axle having an axis of rotation; a pair of longitudinally separated wheel structures disposed on each lateral side of and in supporting relation to said main frame, a first wheel structure of each pair being mounted on opposite ends of said axle and constrained to rotate about the axis of rotation; an endless, inextensible elastomeric belt entrained about each pair of wheel structures; means for oscillatably mounting said axle on the main frame about an oscillation axis parallel to said longitudinal axis; and tensioning means for biasingly pulling said axle away from each pair's other wheel structure.
Claim 2
Dependent Claim
114 words
A belt laying work vehicle comprising: a main frame having a longitudinal axis; a laterally extending rigid axle having an axis of rotation; a pair of longitudinally separated wheel structures disposed on each lateral side of and in supporting relation to said main frame, a first wheel structure of each pair being mounted on opposite ends of said axle and constrained to rotate about the axis of rotation; an endless, inextensible elastomeric belt entrained about each pair of wheel structures; means for oscillatably mounting said axle on the main frame about an oscillation axis parallel to said longitudinal axis; and tensioning means for biasingly pulling said axle away from each pair's other wheel structure.
Claim 3
Dependent Claim
25 words
The belt laying work vehicle of claim 1 wherein said axle mounting means comprises: means for universally swivelling said axle relative to said main frame.
Claim 4
Dependent Claim
49 words
The belt laying work vehicle of claim 1 wherein said axle mounting means comprises: a pivot pin attached to one of said axle and said main frame; and a universally swivelling bearing slidably mounted on said pin and fixedly mounted on the other of said axle and main frame.
Claim 5
Dependent Claim
20 words
The belt laying work vehicle of claim 3 wherein said pivot pin has an axis which constitutes said oscillation axis.
Claim 6
Dependent Claim
30 words
The belt laying work vehicle of claim 1 wherein said tensioning means exerts increasing pulling force on said axle with increasing displacement of said axle toward said other wheel structures.
Claim 7
Dependent Claim
57 words
The belt laying work vehicle of claim 1 wherein said tensioning means comprises: a pair of spring assemblies each having a first end connected to said axle on opposite lateral sides of said oscillation axis and a second end connected to said main frame on the opposite longitudinal side of the axle from said other wheel structures.
Claim 8
Dependent Claim
82 words
The belt laying work vehicle of claim 6 wherein each spring assembly comprises: a cylinder having one end connected to one of said main frame and said axle; a piston structure reciprocatably displaceable in said cylinder and having a rod assembly connected to the other of said main frame and said axle; and a spring disposed in said cylinder and having opposite ends engaged with said cylinder and said piston structure, said spring biasing said piston structure toward said one cylinder end.
Claim 9
Dependent Claim
30 words
The belt laying work vehicle of claim 7 wherein said rod assembly comprises: a piston rod; a yoke; and means for adjusting the distance between said rod and said yoke.
Claim 10
Dependent Claim
39 words
The belt laying work vehicle of claim 8 wherein said adjustment means comprises: a shaft threadably engaged with said rod and said yoke; and means for locking said shaft form rotating relative to one of said rod and yoke.
Claim 11
Dependent Claim
22 words
The belt laying vehicle of claim 6 wherein said spring assemblies are connected to said axle laterally between said first wheel structures.
Claim 12
Dependent Claim
162 words
A belt tensioning apparatus for biasing an idler wheel structure away from an associated driver wheel structure, both of said structures being entrained by an endless inextensible elastomeric belt, and being arranged in supporting relation to a vehicular main frame, said apparatus comprising: a rigid axle universally swivellably mounted on said main frame and on which said idler wheel structure is rotatably mounted; and a spring assembly connected between the axle and main frame and arranged to exert a pulling force on said axle away from the driver wheel structure, said spring assembly including a cylinder having one end connected to one of said main frame and said axle, a piston structure reciprocatably disposed in said cylinder and having a rod assembly connected to the other of said main frame and said axle, and spring disposed in said cylinder and having opposite ends engaged with said cylinder and said piston structure, said spring biasing said piston structure toward said cylinder's one end.
Claim 13
Dependent Claim
162 words
A belt tensioning apparatus for biasing an idler wheel structure away from an associated driver wheel structure, both of said structures being entrained by an endless inextensible elastomeric belt, and being arranged in supporting relation to a vehicular main frame, said apparatus comprising: a rigid axle universally swivellably mounted on said main frame and on which said idler wheel structure is rotatably mounted; and a spring assembly connected between the axle and main frame and arranged to exert a pulling force on said axle away from the driver wheel structure, said spring assembly including a cylinder having one end connected to one of said main frame and said axle, a piston structure reciprocatably disposed in said cylinder and having a rod assembly connected to the other of said main frame and said axle, and spring disposed in said cylinder and having opposite ends engaged with said cylinder and said piston structure, said spring biasing said piston structure toward said cylinder's one end.
Claim 14
Dependent Claim
27 words
The belt laying work vehicle of claim 11 further comprising: means independent of said rod assembly for displacing said piston structure away from said cylinder's one end.
Claim 15
Dependent Claim
17 words
The belt laying work vehicle of claim 11 further comprising: means for adjusting said spring's biasing force.
Claim 16
Independent Claim
100 words
A method for tensioning an endless, inextensible elastomeric belt into frictional driven engagement with one of a pair of wheel structures which are entrained by said belt and which are arranged in supporting relation to a vehicular main frame, comprising: pullingly biasing a main frame mounted, universally swivelable axle on which the other wheel structure is mounted in a longitudinal direction away from the one wheel structure with a predetermined biasing force when the axle occupies an initial position; and increasing the biasing force in response to movement of the axle from the initial position toward the one wheel structure.
Claim 17
Independent Claim
100 words
A method for tensioning an endless, inextensible elastomeric belt into frictional driven engagement with one of a pair of wheel structures which are entrained by said belt and which are arranged in supporting relation to a vehicular main frame, comprising: pullingly biasing a main frame mounted, universally swivelable axle on which the other wheel structure is mounted in a longitudinal direction away from the one wheel structure with a predetermined biasing force when the axle occupies an initial position; and increasing the biasing force in response to movement of the axle from the initial position toward the one wheel structure.
Claim 18
Dependent Claim
66 words
The method of claim 14 wherein said pullingly biasing the axle comprises: changing the length of a spring which is engaged with a piston structure and with a cylinder which are respectively connectable to one member and the other of said axle and frame such that when the axle occupies said initial position said spring's length equals a biasing length corresponding to the predetermined biasing force.
Claim 19
Dependent Claim
71 words
The method of claim 15 wherein said spring length changing comprises: measuring the protrusion distance which a piston rod of said piston structure extends beyond the end of the cylinder when said axle occupies the initial position; rotating a rod adjuster threadably engaged with said one member and said piston rod whenever the protrusion distance is not substantially equal to a predetermined protrusion distance which corresponds to said spring's biasing length.
Claim 20
Dependent Claim
19 words
The method of claim 16 further comprising: counteracting the spring's biasing force on the rod adjuster during such rotating.
Claim 21
Dependent Claim
24 words
The method of claim 17 wherein said counteracting comprises: displacing said piston structure against the biasing force by transmitting pressurized fluid into said cylinder.
Claim 22
Dependent Claim
58 words
The method of claim 18 wherein the other of said wheel structures is pneumatic, said method comprising: subsequent to the protrusion distance equaling the predetermined protrusion distance, draining sufficient pressurized fluid from the cylinder to permit sufficient movement of said piston structure to maintain engagement between the belt and wheel structures upon deflation of the other wheel structure.
Claim 23
Dependent Claim
7 words
The method of claim 16 further comprising:
Claim 24
Dependent Claim
21 words
locking the rod adjuster against rotation relative to one of the one member and the piston rod subsequent to such rotating.
Claim 25
Dependent Claim
21 words
locking the rod adjuster against rotation relative to one of the one member and the piston rod subsequent to such rotating.
Claim 26
Dependent Claim
93 words
A belt laying work vehicle comprising: a main frame having a longitudinal axis; a laterally extending axle having an axis of rotation; a pair of longitudinally separated wheel structures disposed on each lateral side of and in supporting relation to said main frame, one wheel structure of each pair being rotatably mounted on said axle; an endless, inextensible elastomeric belt entrained about each pair of wheel structures; means for universally swivellably mounting said axle on said main frame; and tensioning means for biasingly pulling said axle away from each pair's other wheel structure.
Claim 27
Dependent Claim
93 words
A belt laying work vehicle comprising: a main frame having a longitudinal axis; a laterally extending axle having an axis of rotation; a pair of longitudinally separated wheel structures disposed on each lateral side of and in supporting relation to said main frame, one wheel structure of each pair being rotatably mounted on said axle; an endless, inextensible elastomeric belt entrained about each pair of wheel structures; means for universally swivellably mounting said axle on said main frame; and tensioning means for biasingly pulling said axle away from each pair's other wheel structure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |