Elevator system
First Claim
1. A speed switch for determining the speed of an elevator car relative to a predetermined speed V, comprising:
- an oscillator having a predetermined fixed frequency F,a first counter disposed to provide a first count responsive to F,a latch for latching the first count in reponse to a latch signal L,a memory,means for addressing said memory with the latched first count,said memory being programmed to output a first signal when addressed by a count value which is below a predetermined value C, and to otherwise output a second signal,means providing distance pulses at a rate of P pulses per inch of movement of the elevator car,a second counter disposed to provide a second count responsive to said distance pulses,reference means for providing a reference count R which is a function of V, P and the time T for the first counter to count to C,comparator means for providing a latch signal L for said latch each time the second count and the reference count R have a predetermined relationship,and reset means responsive to each latch signal L for resetting said first and second counters,whereby said memory outputs the second signal when the second count reaches the predetermined relationship with the count R in the time T or more, indicating the car speed is V or less, and the first signal in a time less than T, indicating the car speed is greater than V.
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Accused Products
Abstract
A speed switch for an elevator system which obtains its information from distance pulses generated in response to car travel. The reference speed setting of the switch is a function of the desired predetermined speed at which the switch is to operate, the number of distance pulses produced per inch of car travel, and the time required by a counter to count to a predetermined value. This arrangement facilitates the selection of the reference speed setting of the speed switch, such as by using a thumb switch. An emergency terminal stopping arrangement using the speed switch is also disclosed, as is a new and improved elevator system in which the normal slow-down speed pattern and emergency terminal stop functions are both resposive to distance pulses produced in response to car movement, enabling a terminal slow-down speed pattern to be initiated by circuitry independent of the distance pulses, such as via a notched terminal slow-down blade adjacent to each terminal floor.
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Citations
11 Claims
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1. A speed switch for determining the speed of an elevator car relative to a predetermined speed V, comprising:
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an oscillator having a predetermined fixed frequency F, a first counter disposed to provide a first count responsive to F, a latch for latching the first count in reponse to a latch signal L, a memory, means for addressing said memory with the latched first count, said memory being programmed to output a first signal when addressed by a count value which is below a predetermined value C, and to otherwise output a second signal, means providing distance pulses at a rate of P pulses per inch of movement of the elevator car, a second counter disposed to provide a second count responsive to said distance pulses, reference means for providing a reference count R which is a function of V, P and the time T for the first counter to count to C, comparator means for providing a latch signal L for said latch each time the second count and the reference count R have a predetermined relationship, and reset means responsive to each latch signal L for resetting said first and second counters, whereby said memory outputs the second signal when the second count reaches the predetermined relationship with the count R in the time T or more, indicating the car speed is V or less, and the first signal in a time less than T, indicating the car speed is greater than V. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A terminal stopping system for initiating the stopping of an elevator car in a terminal zone adjacent to each terminal floor of a building in response to the car speed exceeding a predetermined value V at a predetermined distance S from a terminal floor, comprising:
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an elevator car mounted for guided movement in a building having upper and lower terminal floors, hatch switches disposed to establish the predetermined distances S adjacent to each terminal floor, means for actuating each hatch switch associated with a terminal floor as the elevator car approaches a terminal floor, a speed switch for determining the speed of the elevator car relative to a predetermined value V, and a terminal stopping relay responsive to said hatch switches and said speed switch, said terminal stopping relay indicating an emergency stop should be initiated when it becomes deenergized, said speed switch including an oscillator having a predetermined fixed frequency F, a first counter disposed to provide a first count responsive to F, a latch for latching the first count in response to a latch signal L, a memory, means for addressing said memory with the latched first count, said memory being programmed to output a first signal when addresses by a count value which is below a predetermined value C, and to otherwise output a second signal, means providing distance pulses at a rate of P pulses per inch of movement of the elevator car, a second counter disposed to provide a second count responsive to said distance pulses, reference means for providing a reference count R which is a function of V, P and the time T for the first counter to count to C, comparator means for providing a latch signal L for said latch each time the second count and the reference count R have a predetermined relationship, reset means responsive to each latch signal for resetting said first and second counters, and a speed indication relay having electrical contacts, said speed indication relay having first and second states responsive to the first and second signals, respectively, of said memory, said terminal stopping relay being energized by a circuit which includes electrical contacts of said speed indication relay and said hatch switches arranged such that the terminal stopping relay will become deenergized when a hatch switch is actuated while the speed indication relay is in its first state. - View Dependent Claims (11)
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Specification