US3864852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic oscillator for digging bucket teeth
Assignee: BTR Industries Ltd
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Filing: 1973-03-27
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Granted: 1975-02-11
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Expires: 1993-03-27
Abstract
Abstract An excavating device of the type having an open digging bucket being steadily forced at its edge into the material to be excavated so as to fill the bucket, the edge itself being arranged for reciprocation or being provided with one or more cutting teeth which may be reciprocated by means of a hydraulic actuator, there being a valve arrangement for providing hydraulic fluid under pressure to the actuator so that the actuator reciprocates the teeth firstly in one direction and secondly in the opposite direction, the hydraulic actuator comprising a double acting piston and cylinder device wherein flow of fluid to one side of the piston is controlled by a first valve and flow of fluid to the other side of the piston is controlled by second valve, and wherein an arrangement is provided to oscillate the two valves between positions in which fluid flows to one side of the piston and then to the other side of the piston respectively, and further including an oscillator comprising an arrangement responsive to one condition of the first valve to change the condition of the second valve, and an arrangement provided responsive to the same condition of the second valve to change the condition of the first valve.
Inventors
- 👤 Leonard Marshall Lochrie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:17
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/18; B06B1/183; E; E02; E02F; E02F3/00; E02F3/04; E02F3/28; E02F3/36; E02F3/40; E02F3/402; E02F3/405; E02F9/00; E02F9/20; E02F9/22; E02F9/2203; E02F9/221; F; F01; F01L; F01L25/00; F01L25/02; F01L25/04; F01L25/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
290 words
An excavating device having a digging bucket provided with a mouth and having reciprocable cutting means mounted on at least one side of the mouth, comprising means for applying a steady force to the bucket to force it into material to be excavated to fill the bucket, a double acting piston and cylinder device for reciprocating the cutting means, the cylinder having outlet ports at only two spaced apart locations along the cylinder one on either side of the piston and two inlet ports nearer the ends of the cylinder respectively than the outlet ports, first valve means for controlling fluid flow to the cylinder, said valve means reciprocating the piston under normal working conditions in the region between the two outlet ports as said valve means are movable between a first condition in which one of said inlet ports and one of said outlet ports on the opposite side of the piston are open and the other of said inlet and outlet ports are closed, and a second condition in which said other inlet port and said other outlet port are open and said one inlet port and said one outlet port are closed, whereby when the piston drifts in either axial direction from said region the piston at least partly covers said one or said other of the outlet ports so that the fluid flow out of that outlet port is throttled thereby increasing the pressure of fluid in the cylinder on the same side of the piston as that outlet port to resist further movement of the piston in the same direction, and hydraulic oscillator means separate from said piston and cylinder device is provided for oscillating said first valve means between its first and second conditions.
Claim 2
Dependent Claim
290 words
An excavating device having a digging bucket provided with a mouth and having reciprocable cutting means mounted on at least one side of the mouth, comprising means for applying a steady force to the bucket to force it into material to be excavated to fill the bucket, a double acting piston and cylinder device for reciprocating the cutting means, the cylinder having outlet ports at only two spaced apart locations along the cylinder one on either side of the piston and two inlet ports nearer the ends of the cylinder respectively than the outlet ports, first valve means for controlling fluid flow to the cylinder, said valve means reciprocating the piston under normal working conditions in the region between the two outlet ports as said valve means are movable between a first condition in which one of said inlet ports and one of said outlet ports on the opposite side of the piston are open and the other of said inlet and outlet ports are closed, and a second condition in which said other inlet port and said other outlet port are open and said one inlet port and said one outlet port are closed, whereby when the piston drifts in either axial direction from said region the piston at least partly covers said one or said other of the outlet ports so that the fluid flow out of that outlet port is throttled thereby increasing the pressure of fluid in the cylinder on the same side of the piston as that outlet port to resist further movement of the piston in the same direction, and hydraulic oscillator means separate from said piston and cylinder device is provided for oscillating said first valve means between its first and second conditions.
Claim 3
Dependent Claim
60 words
An excavating device as claimed in claim 1 wherein said first valve means comprises a spool valve and wherein said oscillator means provides a pulsating flow of fluid to one end of said spool valve for changing the condition of said valve means, and means being provided for returning said valve means to the initial condition between the fluid pulses.
Claim 4
Dependent Claim
51 words
An excavating device as claimed in claim 2 wherein said oscillator means also provides a pulsating flow of fluid to the other end of the spool valve alternating with the pulsating flow of fluid to the one end of the spool valve to return the spool valve to its initial condiditon.
Claim 5
Dependent Claim
172 words
An excavating device as claimed in claim 3 wherein said oscillator means comprises second valve means moVable between two conditions in which fluid pressure is supplied to opposite ends, respectively of said first valve means, and means being provided for oscillating the second valve means between its two conditions including third valve means movable between two conditions, said second and third valve means being changed from one condition to the other condition by fluid actuated means, said third valve means being connected in said one condition to supply fluid to change the condition of said second valve means from said one to said other condition, said second valve means being connected in said other condition to supply fluid to change the condition of said third valve means from said one to said other condition, and means being provided to change said second and third valve means from their other conditions to their one condition whereby in use said second and third valve means oscillate in sequence between their two conditions of operation.
Claim 6
Dependent Claim
199 words
An excavating device as claimed in claim 4 wherein each of said second and third valve means has an inlet port, an outlet port and a further port which further port, in one condition of operation of each said second and third valve means, is connected to the inlet port of its respective valve means, and in the other condition of operation of each said second and third valve means is connected to the outlet port of its respective valve means, the further port of one of said second and third valve means being connected to supply fluid for changing the condition of another of said second and third valve means from said one to said other condition, and the further port of said another valve means being connected to supply fluid for changing the condition of said one valve means from said one to said other condition, the arrangement being such that when the inlet ports of both said one and said another valve means are connected to a substantially constant pressure source, and the outlet ports thereof are connected to drains, said one and said another valve means oscillate in sequence between their two conditions of operation.
Claim 7
Dependent Claim
143 words
An excavating device as claimed in claim 5 wherein the means to change each of said second and third valve means between its other condition of operation and its one condition is fluid actuated, and that each said valve means is provided with a second further port which, in said one condition of each said valve means is connected to the outlet of its respective valve means, and in said other condition of operation is connected to the inlet of its respective valve means, the second further port of said second valve means being connected to supply fluid to change said third valve means from said other to said one condition, and said second further port of said third valve means being connected to supply fluid to change the condition of said second valve means from said other condition to said one condition.
Claim 8
Dependent Claim
48 words
An excavating device as claimed in claim 6 wherein said second and third valve means comprise spool valves, the fluid actuated means for changing the condition of the valves comprising fluid inlets to the ends of the spool whereby the spool is moved axially between its two conditions.
Claim 9
Dependent Claim
23 words
An excavating device as claimed in claim 5 wherein restrictions are provided in conduits connecting said further ports to the fluid actuated means.
Claim 10
Dependent Claim
21 words
An excavating device as claimed in claim 8 wherein said restrictions are variable whereby the frequency of oscillations may be varied.
Claim 11
Dependent Claim
253 words
An excavating device having a digging bucket provided with a mouth and having reciprocable cutting means mounted on at least one side of the mouth, comprising means for applying a steady force to the bucket to force it into material to be excavated to fill the bucket, a double acting piston and cylinder device for reciprocating the cutting means, first valve means for controlling fluid flow to the cylinder which are movable between two conditions in which fluid is supplied to opposite sides of the piston respectively to reCiprocate the cutting means, second valve means movable between two conditions, each said valve means having fluid actuated means to change the valve from one condition to the other condition and vice versa, said first valve means being connected to fluid actuated means of said second valve means, and said second valve means being connected to fluid actuated means of said first valve means, the arrangement being such that movement of each said valve means from one condition to the other changes the direction in which it acts on the fluid actuated means of the other of said valve means whereby, in use, said valve means each oscillate in sequence between their conditions of operation, and further valve means operable if the reciprocating cutting means oscillate in excess of a predetermined amount in either direction to apply fluid pressure to the fluid actuated means for one of said first and second valve means in a sense to correct the oscillating position of the cutting means.
Claim 12
Dependent Claim
253 words
An excavating device having a digging bucket provided with a mouth and having reciprocable cutting means mounted on at least one side of the mouth, comprising means for applying a steady force to the bucket to force it into material to be excavated to fill the bucket, a double acting piston and cylinder device for reciprocating the cutting means, first valve means for controlling fluid flow to the cylinder which are movable between two conditions in which fluid is supplied to opposite sides of the piston respectively to reCiprocate the cutting means, second valve means movable between two conditions, each said valve means having fluid actuated means to change the valve from one condition to the other condition and vice versa, said first valve means being connected to fluid actuated means of said second valve means, and said second valve means being connected to fluid actuated means of said first valve means, the arrangement being such that movement of each said valve means from one condition to the other changes the direction in which it acts on the fluid actuated means of the other of said valve means whereby, in use, said valve means each oscillate in sequence between their conditions of operation, and further valve means operable if the reciprocating cutting means oscillate in excess of a predetermined amount in either direction to apply fluid pressure to the fluid actuated means for one of said first and second valve means in a sense to correct the oscillating position of the cutting means.
Claim 13
Dependent Claim
45 words
An excavating device as claimed in claim 10 wherein means are provided to bias each of said first and second valve means to one of its conditions of operation in the absence of fluid pressure to the fluid actuated means for its respective valve means.
Claim 14
Dependent Claim
46 words
An excavating device as claimed in claim 10 wherein said first and second valve means are spool valves, and said fluid actuated means for said valve means comprise fluid inlets leading to the ends of the spools whereby the spool is moved axially between its conditions.
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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) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |