US3830336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Personnel bucket brake for hydraulic cranes
Assignee: PITMAN MANUFACTURING COMPANY Inc (PITMAN) A CORP OF
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Filing: 1973-08-22
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Granted: 1974-08-20
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Expires: 1993-08-22
Abstract
Abstract A fluid-pressure responsive brake and actuation system therefor is disclosed which is operable to selectively brake the movement of a pivotally mounted, gravity leveled personnel bucket positioned atop an extensible boom of a crane or aerial device. The brake comprises a closed housing mounted on the bucket with a reciprocable rod centrally disposed within the housing and extending through the bucket wall into registry with an arcuate slot provided in an adjacent, independent braking plate fixably secured to the bucket supporting, shiftable section of the boom. A piston is journaled on the rod within the housing and a brake pad is externally attached to the rod at a point proximal to the braking plate. A high-bias, low-deflection spring within the housing on one side of the piston serves to bias the pad connected thereto into a normal frictional locking position with the braking plate. The opposed face of the piston communicates with a fluid-pressure chamber which in turn is joined by duct means to a two-way pressure-responsive shuttle valve interposed within the overall hydraulic system for raising and lowering the boom. In this manner the biasing spring acts to preclude pivotal movement of the bucket when the boom is stationary and the hydraulic system is at relatively low pressure. However, when the boom pivoting controls are actuated to move the boom, increased pressure against the shuttle valve opens the latter to direct pressurized motive fluid to the brake chamber to thereby move the rod in opposition to the spring. This serves to release the pad from braking contact with the adjacent plate, thus allowing the bucket to pivot under the influence of gravity to maintain the latter in a level position during raising or lowering of the boom.
Inventors
- 👤 J Reimbold
- 👤 W Kamberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:46
CPC Classifications
B; B66; B66F; B66F11/00; B66F11/04; B66F11/044; B66F11/046
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
156 words
A selectively actuatable, fluid-pressure responsive brake assembly for use with a personnel bucket pivotally mounted on a shiftable boom, said brake assembly acting to free the bucket for gravitational leveling during raising and lowering of the boom and locking the bucket when said boom is stationary, the combination with said bucket and boom of: support structure secured to the bucket for movement therewith; a brake plate fixedly carried by the boom in proximal relationship to said support structure; and a hydraulically operated unit carried by the support structure and provided with a shiftable brake pad located to move into frictional engagement with the plate for locking the structure and thereby said bucket to the boom, said unit including means for normally forcing the pad into frictional locking engagement with said plate and hydraulically actuated maans for shifting the pad out of said locking position engaging the plate in response to raising or lowering of the boom.
Claim 2
Dependent Claim
156 words
A selectively actuatable, fluid-pressure responsive brake assembly for use with a personnel bucket pivotally mounted on a shiftable boom, said brake assembly acting to free the bucket for gravitational leveling during raising and lowering of the boom and locking the bucket when said boom is stationary, the combination with said bucket and boom of: support structure secured to the bucket for movement therewith; a brake plate fixedly carried by the boom in proximal relationship to said support structure; and a hydraulically operated unit carried by the support structure and provided with a shiftable brake pad located to move into frictional engagement with the plate for locking the structure and thereby said bucket to the boom, said unit including means for normally forcing the pad into frictional locking engagement with said plate and hydraulically actuated maans for shifting the pad out of said locking position engaging the plate in response to raising or lowering of the boom.
Claim 3
Dependent Claim
108 words
The combination of claim 1 wherein is provided hydraulically actuated piston and cylinder means connected to the boom for raising and lowering the latter, and hydraulic circuit means coupled to said piston and cylinder means for directing pressurized hydraulic fluid to either one end or the other of said piston and cylinder means to effect raising or lowering of the boom, said hydraulically operated unit being operatively connected to said circuit for actuation by pressurized fluid directed to either end of said piston and cylinder means to effect shifting of the brake pad out of frictional engagement with said plate during either raising or lowering of the boom.
Claim 4
Dependent Claim
105 words
The combination of claim 2 wherein said unit includes a housing, a shiftable rod projecting from the housing toward said plate and carrying said pad thereon, a piston secured to the rod within the housing, means within the housing engaging said piston on the side thereof forcing said pad into frictional locking engagement with the plate, and means for directing pressurized hydraulic fluid from said circuit to the housing for shifting the piston and thereby the rod through a displacement to move the pad out of locking engagement with the plate against the action of said biasing means during raising and lowering of the boom.
Claim 5
Dependent Claim
32 words
The combination of claim 3 wherein is provided means for effecting unlocking of the pad from said plate prior to raising or lowering of the boom by said piston and cylinder means.
Claim 6
Dependent Claim
303 words
A selectively actuatable, fluid-pressure responsive brake assembly for use with a personnel bucket pivotally mounted on a shiftable boom, said brake assembly acting to free the bcket for gravitational leveling during raising and lowering of the boom and locking the bucket when said boom is stationary, the combination with said bucket and boom of: first and second plates positioned in adjacent, spaced relationship, said first plate being fixedly connected to said boom, and said second plate being connected to said bucket for movement therewith independent of said first plate; a closed housing mounted on one of said plates; a reciprocable actuating rod positioned within said housing and extending therefrom to pass through said adjacent plate, the latter being provided with a slot configured and arranged to allow said rod to travel therein during movement of said bucket; a brake pad connected to said rod externally of said housing and positioned to selectively communicate with said adjacent plate in response to reciprocation of said rod to effect a frictional, braking contact between the pad and adjacent plate; a fluid pressure actuatable piston within said housing and journaled on said rod for reciprocation therewith; biasing means within said housing on one side of said piston operable to bias the latter in a direction to cause braking contact between said pad and adjacent plate, the opposite side of said piston communicating with a fluid pressure chamber within said housing; and means operatively connected to said chamber for increasing the fluid pressure therein during raising and lowering of said boom, whereby, when said fluid pressure is of sufficient magnitude to overcome the oppositely directed force of said biasing means, said piston and rod move in a direction to break the contact between said pad and adjacent plate, thereby freeing said bucket and allowing the latter to move.
Claim 7
Dependent Claim
303 words
A selectively actuatable, fluid-pressure responsive brake assembly for use with a personnel bucket pivotally mounted on a shiftable boom, said brake assembly acting to free the bcket for gravitational leveling during raising and lowering of the boom and locking the bucket when said boom is stationary, the combination with said bucket and boom of: first and second plates positioned in adjacent, spaced relationship, said first plate being fixedly connected to said boom, and said second plate being connected to said bucket for movement therewith independent of said first plate; a closed housing mounted on one of said plates; a reciprocable actuating rod positioned within said housing and extending therefrom to pass through said adjacent plate, the latter being provided with a slot configured and arranged to allow said rod to travel therein during movement of said bucket; a brake pad connected to said rod externally of said housing and positioned to selectively communicate with said adjacent plate in response to reciprocation of said rod to effect a frictional, braking contact between the pad and adjacent plate; a fluid pressure actuatable piston within said housing and journaled on said rod for reciprocation therewith; biasing means within said housing on one side of said piston operable to bias the latter in a direction to cause braking contact between said pad and adjacent plate, the opposite side of said piston communicating with a fluid pressure chamber within said housing; and means operatively connected to said chamber for increasing the fluid pressure therein during raising and lowering of said boom, whereby, when said fluid pressure is of sufficient magnitude to overcome the oppositely directed force of said biasing means, said piston and rod move in a direction to break the contact between said pad and adjacent plate, thereby freeing said bucket and allowing the latter to move.
Claim 8
Dependent Claim
26 words
The combination of claim 5, wherein said second plate comprises the backwall of an upstanding hanger pivotally connected to said boom and attached to said bucket.
Claim 9
Dependent Claim
50 words
The combination of claim 6, wherein said housing is mounted on the face of said second plate removed from said first plate, said reciprocable rod being centrally disposed therein and extending through the latter, said second plate being provided with an aperture therein to permit passage of said rod therethrough.
Claim 10
Dependent Claim
83 words
The combination of claim 3, wherein a first brake pad is attached to said rod and positioned to engage the face of said first plate removed from said second plate, a second apertured brake pad being attached to the second plate and positioned in the space between the back wall and first plate with said rod extending therethrough, said first and second pads normally cooperatively engaging opposite faces of said first plate to prevent movement of the bucket when said boom is stationary.
Claim 11
Dependent Claim
37 words
The combination of claim 8, wherein said housing is generally cylindrical in shape, said biasing means being positioned between said piston and second plate and operable to bias the piston in a direction away from the latter.
Claim 12
Dependent Claim
15 words
The combination of claim 9, wherein said biasing means is a high-bias, low-deflection spring unit.
Claim 13
Dependent Claim
44 words
The combination of claim 10, wherein said high-bias, low-deflection spring unit comprises a plurality of discrete, generally cup-shaped members fabricated of spring steel and slidably journaled on said rod with the open face of each member facing the open face of an adjacent member.
Claim 14
Dependent Claim
36 words
The combination of claim 11, wherein said high-bias, low-deflection spring unit is constructed to be deflected to an extent to release said brake by an opposing pressure within said fluid pressure chamber of under 130 psi.
Claim 15
Dependent Claim
53 words
The cOmbination of claim 9, wherein said rod extends through the end of said housing removed from said plates, said housing being provided with manually actuatable means externally mounted on said end thereof operable to act on said rod to move the latter in a direction toward said plates to release said brake.
Claim 16
Dependent Claim
43 words
The combination of claim 13, wherein said manually actuatable means is a pivotally mounted, spring-biased cam member operable to be turned about the pivot axis thereof and engageable with said rod to effect axial movement thereof against the action of said biasing means.
Claim 17
Dependent Claim
32 words
The combination of claim 14, wherein said cam member is provided with a detent on the surface thereof operable to receive said rod and releasably hold the latter in a brake-releasing position.
Claim 18
Dependent Claim
27 words
The combination of claim 5, wherein said housing is provided with an aperture in the portion thereof circumscribing said biasing means to effect venting of said portion.
Claim 19
Dependent Claim
38 words
The combination of claim 5, wherein a stop sleeve is interposed in the portion of said housing receiving said biasing means and disposed in circumscribing relationship to the latter for limiting the extent of travel of said piston.
Claim 20
Dependent Claim
292 words
A braking system for use with a movable personnel bucket brake mounted on a fluid-pressure actuated boom to permit free movement of the bucket during raising and lowering of the boom and to lock the bucket when the boom is stationary, comprising: a supply of motive fluid; actuating means for raising and lowering the boom; conduit means operatively interconnecting said supply and the boom actuating means, and defining a hydraulic circuit therebetween to effect selective raising and lowering of said boom; means interposed within said circuit operable to force motive fluid therethrough under pressure; directional means interposed within said circuit operable to selectively direct motive fluid through said circuit to a part of the boom actuating means to effect raising of said boom, and for selectively directing motive fluid through the circuit to another part of the boom actuating means to effect lowering of the boom; pressure responsive means interposed within said circuit operable to permit flow therethrough when the fluid pressure within the circuit reaches a first predetermined magnitude; selectively actuatable fluid pressure responsive brake means adapted to be operatively connected to said personnel bucket and operable to hold the latter against movement when said boom is stationary, said brake means being selectively actuatable to release said bucket and allow movement thereof when the fluid pressure therein reaches a second predetermined magnitude; and conduit means interconnecting said pressure responsive means and brake means whereby, when the fluid pressure within the circuit reaches said first predetermined magnitude, motive fluid is directed to said brake means, said brake being actuated to release said bucket and allow movement thereof as soon as fluid under a pressure equal to or exceeding said second predetermined magnitude thereof is directed to said brake means from the circuit.
Claim 21
Dependent Claim
292 words
A braking system for use with a movable personnel bucket brake mounted on a fluid-pressure actuated boom to permit free movement of the bucket during raising and lowering of the boom and to lock the bucket when the boom is stationary, comprising: a supply of motive fluid; actuating means for raising and lowering the boom; conduit means operatively interconnecting said supply and the boom actuating means, and defining a hydraulic circuit therebetween to effect selective raising and lowering of said boom; means interposed within said circuit operable to force motive fluid therethrough under pressure; directional means interposed within said circuit operable to selectively direct motive fluid through said circuit to a part of the boom actuating means to effect raising of said boom, and for selectively directing motive fluid through the circuit to another part of the boom actuating means to effect lowering of the boom; pressure responsive means interposed within said circuit operable to permit flow therethrough when the fluid pressure within the circuit reaches a first predetermined magnitude; selectively actuatable fluid pressure responsive brake means adapted to be operatively connected to said personnel bucket and operable to hold the latter against movement when said boom is stationary, said brake means being selectively actuatable to release said bucket and allow movement thereof when the fluid pressure therein reaches a second predetermined magnitude; and conduit means interconnecting said pressure responsive means and brake means whereby, when the fluid pressure within the circuit reaches said first predetermined magnitude, motive fluid is directed to said brake means, said brake being actuated to release said bucket and allow movement thereof as soon as fluid under a pressure equal to or exceeding said second predetermined magnitude thereof is directed to said brake means from the circuit.
Claim 22
Dependent Claim
68 words
The system of claim 18, said conduit means including a first boom raising portion interconnecting said directional means and boom to permit pressurized fluid-flow therethrough to raise the boom, and a second boom lowering portion interconnecting said directional means and boom to permit pressurized fluid-flow therethrough to lower the boom, said directional means being selectively positionable to direct pressurized fluid through said first and second portions as desired.
Claim 23
Dependent Claim
51 words
The system of claim 19, wherein each of said conduit portions is connected to said supply of motive fluid such that when pressurized fluid is being directed through one of said portions, the other portion serves as a return conduit for returning fluid from said boom actuating means to the supply.
Claim 24
Dependent Claim
85 words
The system of claim 20, wherein an internally piloted, one-way sequencE valve is interposed within said respective first and second portions between said boom actuating means and the directional means, said sequence valves being operable to perclude flow of motive fluid through said respective portions in a direction from the directional means to the boom actuating means until the fluid pressure therein reaches a third predetermined magnitude, and operable to allow unrestricted flow of motive fluid therethrough from the boom actuating means to the supply.
Claim 25
Dependent Claim
104 words
The system of claim 21 wherein said pressure responsive means comprises: a first duct connected to said first conduit portion on the input side of the sequence valve interposed within the latter; a second duct connected to said second conduit portion on the input side of the sequence valve interposed within the latter; and a two-way, shiftable shuttle valve interconnecting said first and second ducts with conduit means interconnecting the shuttle valve and brake means, said shuttle valve being adapted to permit flow of motive fluid to said brake means when the fluid pressure within either of said ducts reaches said first predetermined magnitude.
Claim 26
Dependent Claim
32 words
The system of claim 22, wherein said first predetermined magnitude is about 130 psi, said second predetermined magnitude is less than 130 psi, and said third predetermined magnitude is about 500 psi.
Claim 27
Dependent Claim
23 words
The system of claim 18, wherein said means for forcing motive fluid through said conduit means under pressure is a fixed displacement pump.
Claim 28
Dependent Claim
29 words
The system of claim 24, wherein said directional means is interposed in said circuit on the output side of said pump and comprises a four-way, three-position directional flow valve.
Claim 29
Dependent Claim
198 words
The system of claim 18, wherein brake means comprises: first and second plates positioned in an adjacent, spaced relationship, said first plate being adapted to be fixedly connected to said boom, and said second plate being adapted to be connected to said bucket for movement therewith independent of said first plate; a closed housing mounted on one of said plates; a reciprocable actuating rod positioned within said housing and extending therefrom to pass through an adjacent plate, the latter being provided with a slot configured and arranged to allow said rod to travel therein during movement of said bucket; a brake pad connected to said rod externally of said housing and positioned to selectively engage said adjacent plate in response to reciprocation of said rod to effect a frictional, braking contact between the pad and adjacent plate; a fluid pressure actuatable piston within said housing and journaled on said rod for reciprocation therewith; and biasing means within said housing on one side of said piston operable to bias the latter in a direction to cause braking contact between said pad and adjacent plate, the opposite side of said piston communicating with a fluid pressure chamber within said housing.
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |