1. A rock anchor which includes an elongate, flexible element with first and second ends, an anchor expansion mechanism at the first end, a tubular barrel into which the second end extends, and a locking arrangement inside the barrel which permits movement of the element in a first direction in the barrel and which locks the element to the barrel when the element moves in a second direction, opposing the first direction, in the barrel.
2. A rock anchor according to claim 1 wherein the tubular barrel has a first, inner mouth and a second, outer mouth and a passage between the mouths and wherein the locking arrangement includes a wedge device, inside the passage, which is engageable with a surface of the passage, of complementary taper to the wedge device, and through which the elongate element extends, and a biasing member which urges the wedge device towards the surface of complementary taper.
3. A rock anchor according to claim 2 wherein the elongate, flexible member includes a weakened zone between the second, outer mouth of the tubular barrel and the biasing member.
4. A rock anchor according to any one of claims 1 to 3 wherein the expansion mechanism includes an impact sleeve, with an outer wedge surface, and a passage into which the first end of the elongate element extends, and a shell arrangement which, at least partly, surrounds the wedge surface.
5. A rock anchor according to claim 1 wherein the expansion mechanism includes a wedge component which has a leading end and a trailing end and which extends around the first end of the elongate element, the leading end of the wedge component extending beyond the first end of the elongate element and the wedge component being of reducing cross section towards the trailing end, a shell arrangement which has an inner cavity of complementary shape to the wedge component which is located at least partly within the inner cavity, the shell arrangement having a base which surrounds the elongate element, and stop structure on the elongate member located so that when the elongate element is moved in an axial direction, to cause the leading end of the wedge component to strike a reaction surface, the wedge component is driven into the inner cavity thereby to expand the shell arrangement.
6. A rock anchor according to claim 1 wherein the locking arrangement includes stop structure on the elongate element near the second end, a wedge member around the elongate element, a biasing member which acts between the stop structure and the wedge member and which tends to displace the wedge member away from the stop structure, and wherein the stop structure and the wedge member are positioned inside the barrel and the second end of the elongate element is located within, and not protruding from, the tubular barrel.
7. A rock anchor according to any one of claims 1 to 6 wherein the elongate flexible element is an elongate cable which is formed from a plurality of helically wound wires which extend around a longitudinally extending hollow core.
8. A rock anchor according to any one of claims 1 to 7 which includes a load-distributing face plate, with an inner side and an outer side, at one end of the tubular barrel and a mechanism which is actuable to exert force on the inner side.
9. A rock anchor which includes an elongate cable which is formed from a plurality of helically wound wires which extend around a longitudinally extending hollow core and an anchor expansion mechanism at a first end of the cable and, at least, a load-distributing face plate at a second end of the cable.
10. A method of reinforcing a rock which includes the steps of forming a hole into the rock from a rock face, placing an elongate, flexible element in the hole, urging a first end of the elongate element towards a bottom of the hole thereby to actuate an anchor expansion mechanism which is engaged with the first end, applying a tensile force to the elongate element by exerting an expansion force between a portion of the elongate element, which extends from the hole, and the rock face, providing a weakened zone in the elongate element, near the rock face, which breaks when the tensile force is greater than a predetermined value and, upon breakage, actuating a locking arrangement to lock the elongate element to a face plate at the rock face.
11. A method according to claim 10 wherein, after actuation of the locking arrangement, a fluent settable material is injected into the hole, around the elongate element, and air inside the hole is allowed to escape to atmosphere through a longitudinally extending hollow core in the elongate member.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A light emitting diode lighting system comprising:
(a) at least one light emitting diode;
(b) a power supply; and
(c) a power management system that controls operating temperature of said diode(s) to oscillate around a predetermined value in a predetermined range.
2. The system as recited in claim 1, wherein said power management system further comprises a comparator including a pair of inputs and an output, wherein one input is coupled to an output of a temperature sensor and another input is coupled to a reference.
3. The system as recited in claim 2, wherein the output of the comparator is coupled to a power modulator including a pulse width modulator or a bit stream modulator that modulates an incoming DC power before the power is delivered to power said diode(s).
4. The system as recited in claim 2, wherein the output of the comparator is coupled to a secondary winding of a power transformer through a switch, wherein said switch further includes a power transistor.
5. The system as recited in claim 2, wherein said temperature sensor is placed within a predetermined distance to said light emitting diode(s).
6. The system as recited in claim 2, wherein said temperature sensor is a part of said light emitting diode(s).
7. The system as recited in claim 2, wherein said temperature sensor comprises an infrared sensor.
8. The system as recited in claim 2, wherein said reference is generated by a controller.
9. The system as recited in claim 1, wherein said power management system includes a means of communicating with a remote control and adjusting said predetermined value of the temperature.
10. A light emitting diode lighting system comprising:
(a) at least one light emitting diode;
(b) a power supply; and
(c) a power management system that controls difference between an operating temperature of said light emitting diode(s) and an ambient temperature to oscillate around a predetermined value in a predetermined range.
11. The system as recited in claim 10, wherein said power management system further comprises a comparator including a pair of inputs and an output, wherein one input is coupled to an output of a temperature sensor and another input is coupled to a reference, wherein said reference is related to the ambient temperature measured by an ambient temperature sensor.
12. The system as recited in claim 11, wherein the output of the comparator is coupled to a power modulator including a pulse width modulator or a bit stream modulator that modulates an incoming DC power before the power is delivered to power said light emitting diode(s).
13. The system as recited in claim 11, wherein the output of the comparator is coupled to a secondary winding of a power transformer through a switch, wherein said switch further includes a power transistor.
14. The system as recited in claim 11, wherein said temperature sensor is placed within a predetermined distance to said light emitting diode(s).
15. The system as recited in claim 11, wherein said temperature sensor is a part of said light emitting diode(s).
16. The system as recited in claim 11, wherein said temperature sensor comprises an infrared sensor.
17. The system as recited in claim 11, wherein said reference is generated by a controller.
18. The system as recited in claim 10, wherein said power management system includes a means of communicating with a remote control and adjusting said predetermined value of the temperature.
19. A method of operating a lighting system including at least one light emitting diode, the method comprising:
(a) determining operating temperature of the light emitting diode (s) by a controller of the lighting system;
(b) generating a reference as one input of a comparator based upon determined temperature;
(c) forcing the operating temperature of the light emitting diode(s) to oscillate around a predetermined value related to said reference by a thermal feedback loop.
20. The method as recited in claim 19, wherein said method further comprises modulating an incoming power by a pulse width modulator or a bit stream modulator before the power is delivered to power the light emitting diode(s).