EP0047629A1

EP0047629A1 - Ski annunciator

Info

Publication number: EP0047629A1
Application number: EP81304005A
Authority: EP
Inventors: Martin James Moore
Original assignee: WINTER AND SUMMER PURSUITS Ltd
Current assignee: WINTER AND SUMMER PURSUITS Ltd
Priority date: 1980-09-09
Filing date: 1981-09-02
Publication date: 1982-03-17
Also published as: AU7503981A

Abstract

An annunciator, suitable for attachment to a ski (7), to facilitate location of the ski when it becomes detached from the skier and comes to rest concealed in snow or undergrowth.

A transmitter (3, 13) is controlled by means of a switch (2) mountable on a ski so located that, when a ski boot (10) is fitted to the ski, the switch means (2) is forced to a state in which the transmitter (3,13) is held inactive.

The switch may be pressure-operated and so mountable as to be squeezed by a ski boot fitted to the ski or may have magnetically-operated contacts and be attachable to a ski brake along with a bar magnet.

Description

The invention relates to a ski annunciator.
A ski annunciator is a device which in use is attached to a ski and is intended to facilitate the location of a runaway ski which disappears from view, buried in snow or entangled in undergrowth, by producing an output signal enabling the owner to find it. It is important that the annunciator should be capable of reliable operation in such situations.
Previously proposed ski annunciators have weaknesses which may prevent their operating reliably in the situations referred to above. For example, in one case, in which a clockwork noise generator is proposed, snow, ice, or undergrowth could easily jam the mechanism and prevent operation. In another case, in which it is proposed to use a switch with a pullout plug to activate an electrical noise generator, snow or undergrowth could be forced into the switch and disable it, thereby terminating or preventing operation.
It is an object of the present invention to provide an annunciator, arranged for fitting to a ski, which is capable of reliable operation when buried in snow or the like.
According to the invention, an annunciator, arranged for fitting to a ski, includes a transmitter and electrical control means for controlling the transmitter, wherein the control means includes switch means having respective first and second states, the arrangement being such that the transmitter is switched on when the switch is in the first state and switched off when the switch is in the second state, the switch means being such as to be mountable on a ski so located that, when a ski boot is fitted to the ski, the switch means is forced to its said second state by the boot and goes to its first state when the boot is removed from the ski.
Advantageously, the switch means is a pressure-operated switch suitable for mounting on a ski, located so as to be under the sole of a boot fitted to the ski.
Advantageously, the switch means is a pressure-operated switch suitable for mounting on a ski so located as to be in contact with the front portion of the sole of a boot fitted to the ski.
Alternatively, the switch means includes a member with magnetically-operated switch contacts and an operating magnet suitable for mounting on a spring-loaded brake on a ski, so located that the member with the switch contacts lies close to the operating magnet when the ski-brake is held non-operative and the member with the switch contacts is remote from the magnet when the ski-brake is free and operative.
Preferably, the annunciator includes a body portion located at one end of a generally rectangular plate member, and the pressure-operated switch is located at the other end of the plate member.
Advantageously, the transmitter includes a sound generator.
Preferably, the sound generator is so positioned that, when the annunciator is fitted to a ski, the output port of the sound generator lies a short distance above the ski in an open reverberation cavity bounded on one side by the ski.
Advantageously, the sound generator is electrically powered, or, alternatively, the sound generator is gas powered.
Preferably, the control means is arranged to provide interrupted operation of the transmitter.
Preferably, the control includes delay means for providing a delay before the transmitter operates.
Preferably, the delay is several seconds.
Preferably, the annunciator includes a further manually operable arming switch.
Advantageously, the annunciator includes theft alarm control means arranged, after activation, to detect movement of the annunciator and to switch on the transmitter when movement is detected, and means for activating the theft alarm control means.
Advantageously, the theft alarm control means is arranged to distinguish between short-term movement, consistent with accidental disturbance, and prolonged movement, consistent with deliberate removal.
Preferably, the theft alarm control means includes delay means arranged to provide a delay period and the theft alarm control means is arranged not to switch on the transmitter before the end of the delay period, when movement is detected.
Preferably, the means for activating the theft alarm control means is a removable key which activates the theft control means on removal.
Preferably, the key is arranged as a tab having a plurality of teeth extending from a backbone.
Preferably, the key includes a magnet on a tooth as the means of identifying the key to the theft alarm control means.
A ski annunciator according to an embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Fig. 1 is a part side elevation of a ski in the region where a boot is attached, showing an annunciator in place with a pressure-operated switch located under the sole of the boot,
Fig. 2 is a plan view of Fig. 1 without the boot,
Fig. 3 is a part side elevation generally similar to that of Fig. 1 but showing a preferred arrangement of locating an acoustic radiator adjacent to a cavity,
Fig. 4 is a plan view of Fig. 3 without the boot,
Fig. 5 is a part side elevation of a ski in the region where a boot is attached, showing a pressure-operated switch located for operation by the tip of the boot,
Fig. 6 is a part side elevation of a ski brake having the components of a magnetically operated switch attached to it,
Fig. 7 is a diagrammatic side elevation of a ski annunciator including burglary alarm facilities,
Flig 8 is a diagrammatic representation of an arming- disarming key for use with the burglary alarm annunciator of Fig. 6,
Fig. 9 is a flow diagram representation of the operations performed by logic means in the burglary alarm annunciator,
Fig. 10 is a block diagram representation of logic means suitable for the burglary alarm annunciator,
Fig. 11 is a diagrammatic representation of a pressure-operated switch suitable for operation by the action of a ski-boot on a ski, and
Fig. 12 shows an alternative switch construction to that of Fig. 11.

With reference to Figs. 1 to 4, an annunciator includes a body portion 1 and a pressure-operated control switch 2. The body portion 1 and the pressure-operated switch 2 are located at opposite ends of a mounting plate 8 which is so attached to a ski 7 that the switch 2 lies under the sole of a user's boot 10 when the boot is in place. The body portion 1 is clear of the boot 10.
The body portion 1 of the annunciator consists of a protective housing which encloses an audible alarm transducer 3, an electrical audio frequency signal generator (not shown) which is connected to drive the transducer 3, and a battery 6. An arming switch 5 and a disarming switch 4 are accessible from outside the housing, the arming switch 5 being used to switch the unit on when the ski is in use and the disarming switch 4 being used to switch the unit off when the ski is not in use. Control of the annunciator passes to the pressure-operated switch 2 when the unit is switched on. The switches 4 and 5 are push-to-operate switches suitably arranged to resist the ingress of moisture into the housing..
The remaining parts of the ski 7 are standard fittings such as a safety release fitting 9 which is arranged to hold the toe of the boot 10.
The mounting plate 8 lies between the safety release fitting 9 and the ski 7 with the pressure-operated switch 2 and the body portion 1 of the annunciator on opposite sides of the safety fitting 9.
A suitable pressure-operated switch 2 is shown in detail in Fig. 11. In the pressure-operated switch 2 a micro-switch 2c is used, and is housed in a moulded enclosure having relatively thick walls 2e and relatively thin walls 2f intended to permit the thick walls 2e to be pushed together with little deformation. The walls 2e are pushed apart by means of a helical spring 2d capable of exerting a force of several pounds. The surface area of the walls 2e should be about ..5 in². Additional springs may be used to increase the operating forces, or alternaitvely, the springs may be replaced by resilient material 2h which surrounds the switch 2c, as shown in Fig. 12.
The positioning of the pressure-operated control or activating switch 2 under the sole of the boot, so as to be acted on directly by the boot, is advantageous in that it permits the use of a switch with a forceful enough switching action to ensure that it operates consistently when the ski is buried in snow or undergrowth.
An alternative position for the control or activating switch 2 is shown in Fig. 5. The switch is so located at the safety release fitting 9 as to come into direct contact with the toe of the boot 10, where the force between the boot 10 and the safety release fitting 9 is such as to permit, as before, the use of a s itch 2 with the necessary forceful switching action. Here, the switch 2 would fit into a recess in the binding 9.
As shown in the arrangement of Fig. 6, it is possible to include a small bar magnet 2a and a magnetically-operated switch 2b in a ski brake mechanism which operates when a ski breaks free of a user's boot. The ski brake has a biassing spring 2g strong enough to operate when the ski is buried in snow or the like.
In the arrangement shown in Figs. 1 to 4, an audible alarm transducer 3 acts as an ernegy radiator. In Figs. 3 and 4, transducer 3 is positioned below an overhanging ledge of the casing 1, so as to have its output port communicating with a cavity 12 between the ledge and the upper surface of the ski 7. The distance of the output port of the transducer 3 from the ski 7 is so chosen as to provide a reverberation cavity 12 so that the sound vibration is enhanced and the sound output from the transducer is less easily blockable by snow. It has been found that a gap of 7 to 10 mm. is suitable for an operating frequency of 1 kHz.
The transducer 3 is fully exposed to ambient conditions and must be protected by, for example, cadmium plating to resist corrosive attack. The transducer 3 is required to operate at about 6V and to sink about 100 mA current to provide an adequate output noise level.
In Fig. 3 there is shown an electrically operated control circuit represented diagrammatically by a circuit board 13 which responds to the switch 2 and controls energisation of the transducer 3.
The control circuit 13 is controlled by the switch 2 and, when activated, provides an initial delay before energising the transducerS. The control circuit 13 provides intermittent energisation of the transducer 3 after the initial delay. The initial delay in energisation of the transducer 3 permits a fallen skier a short time to recover his ski and seeks to avoid the nuisance caused by the alarm sounding when the ski is recoverable quickly, and intermittent operation provides extended operation relative to a continuously operated alarm.
An alternative audible alarm transducer may be a gas-driven whistle which would use a compact compressed gas supply as its power source. The control circuit would then be required to operate a valve connecting the gas supply to the gas-driven whistle.
Other forms of alarm such as a radio transmitter may be used, and a search receiver incorporated in the user^ts ski pole, for example.
Referring now to Fig. 7, the component parts of a burglary annunciator are an activating key 14, a reed switch 15 operable by means of the activating key 14 to activate and deactivate burglary facility of the annunciator, a trembler switch 16 to detect movement of the annunciator, a circuit board 17 containing an electrical system for processing signals from the trembler switch 16 and for driving the acoustic transducer 3 as appropriate. The battery 6 provides electrical power to the electrical system by way of the reed switch 15 which is operated by a magnet 18 located on the activating key 14.
The arming key 14, shown in Fig. 2, has a plurality of teeth (five in this case) of differing lengths. Complementary wells (not shown) in the body of the annunciator ensure that each arming key 14 can operate only one annunciator, and that a variety of key configurations are possible. A magnet 18 is attached to one tooth. The tooth with the magnet lies closest to the reed switch 15 in the disarmed condition.
With reference to Fig. 9, a user of skis would at some stage leave skis unattended, usually parked upright in a rack or stack in snow (action 11) having disabled its locator.
The ski user then arms each burglary annunciator (action 12) by removing the key tab 14 (Fig. 1). Each annunciator is then sensitive to movement (decision 13). So long as a ski is not disturbed there is no action from its burglary annunciator (decision NO at decision 13). Should a ski be disturbed (decision YES) the disturbance is detected by the annunciator as movement of the trembler switch/6.
The annunciator waits for 3 seconds (action 14) allowing time to insert the key tab 14 (decision 15) without triggering the alarm should the disturbance be caused by the owner (decision YES). If the key tab 14 has not been inserted the annunciator checks again for movement (decision 16). If the ski is no longer being moved (decision NO) the alarm is not activated, so the annunciator is not triggered by short-term iisturbances. Should the disturbance still exist (decision YES) the annunciator waits for 3 seconds (action 17) and checks again for disturbance (decision 18). Continuing disturbance (decsion Yes) at this point triggers the alarm (action 19).
As is evident from Fig. 9, the annunciator includes delays in responding to disturbances as a means of avoiding triggering during short disturbances consistent with accidental movement of the ski while being able to react to continuing disturbance consistent with unauthorised removal.
The three second delays are considered to be suitable but other delay periods may be used.
As shown in Fig. 10, in a logic circuit suitable for inclusion in an annunciator, the reed switch 15 controls connection of the battery 6 to the power input terminals of the circuit components under the influence of the magnet 18 of the key tab 14 (Fig. 7). The reed switch 15 is arranged, in known manner, to be open when the annunciator is disarmed and to be closed when it is armed.
The battery 6 is then connected to a retriggerable monostable flip-flop 26 by way of the trembler switch 16. The flip-flop 26 acts to provide a continuous "1" level binary output so long as the trembler switch 16 is vibrating, and a binary "0" output when the trembler switch 16 is not vibrating.
The output signal from the monostable flip-flop 26 is lapplied to the data input ports of three bistable flip- flops 23, 24 and 25 which are clocked sequentially by a memory selector 22. This arrangement provides that each bistable flip-flop is loaded at the time it is clocked with the data provided by the monostable flip-flop 26. The sequential memory selector is driven by a clock oscillator 20 by way of a clock period divider 21 in order to provide updating of each bistable flip-flop at 3 second intervals (corresponding to the 3 second delay referred to in Fig. 9). The sequential memory selector 22 may consist of a shift register connected as a three-stage ring counter in known manner.
The output signals from the bistable flip- flops 23, 24 and 25 are applied to an AND gate 28. The AND gate 28 will provide an output "1" level when all its inputs are at logic "1" also. The AND gate 28 controls a two-input AND gate 29 which its other input port connected to the clock oscillator 20 by way of a divider 32. The two-input AND gate 29 is arranged to energise an output transducer 30. The AND gate 29 will transmit pulses from the divider 32 to the transducer 30 only when the output level of the AND gate 28 is a logic "I", that is, when all three of the bistable flip- flops 23, 24 and 25 are loaded with logic "1".
The circuit includes a monostable flip-flop 31 connected to receive an input trigger signal from the junction of a capacitor 32 and a resistor 33 connectable to the battery 3 by way of the reed switch 15. The monostable flip-flop 31 is connected to the CLEAR input ports of the bistable flip- flops 23, 24 and 25. The monostable flip-flop 31 is triggered on when the annunciator is first armed, and applies a CLEAR signal to the bistable flip- flops 23, 24 and 25 for a set period. This ensures that the bistable flip- flops 23, 24 and 25 are loaded with logic "0" levels initially.
In operation, the bistable flip-flop 23, say, is switched by the memory selector 22 to receive data, and will receive a logic "1" signal from the monostable flip-flop 26 if the trembler switch 16 is vibrating. If the trembler switch 16 is not vibrating the bistable flip-flop 23 receives a logic 0. The bistable flip-flop 23 is then switched to ignore data and will retain the data it received from the monostable flip-flop 26.
The bistable flip-flop 24 is switched next to receive data, some 1.5 seconds later, and performs the same operations as the bistable flip-flop 23.
The bistable flip-flop 25 is switched subsequently, some 1.5 seconds after the bistable flip-flop 24, and performs the same operations as before.
The operation now returns to the bistable flip-flop 23 which stores data from the monostable flip-flop 26 as it stands 3 seconds later on.
The effect of the continual updating of the bistable flip- flops 23, 24 and 25, respectively, at 3 second intervals is to provide some distinction between short-term and long-term disturbances. The alarm is triggered only when all three bistable flip- flops 23, 24, and 25 provide logic "1" outputs. This occurs only when a disturbance persists for more than 3 seconds.
The period over which a disturbance is ignored may be varied by changing the divide ratio of the div der 21, by altering the number of bistable flip-flops, or further delays may be inserted by means of a further group of bistable flip-flops which are loaded only after the AND gate 28 provides a logic "1" output.
The burglarly annunciator may provide an audible or visual (or both) output when triggered.
The reed switch may be replaced by a Hall Effect Sensor and an associated power control circuit.
Suitable components for the logic circuit of Fig. 10 are as follows:

Clock oscillator (2) - NE/SE 555.
Dividers (21, 32) - SN 7492.
Sequential Memory Selector - SN 7494.
Monostable flip-flops (26, 31) - SN 74123.
Memories (23, 24, 25) - SN 7474.
Gate (28) - SN 74515
GATE (29) - SN 7409

The components are available from several semiconductor manufacturers including Texas Instruments and National Semiconductor and their distributors.
It should be evident to a person skilled in the art that the logic circuit may be constructed from other components, including MOS components.

Claims

1. An annunciator, arranged for fitting to a ski, including a transmitter and electrical control means for controlling the transmitter, wherein the control means includes switch means having respective first and second states, the arrangement being such that the transmitter is switched on when the switch is in the first state and switched off when the switch is in the second state, the switch means being such as to be mountable on a ski so located that, when a ski boot is fitted to the ski, the switch means is forced to its said second state by the boot and goes to its first state when the boot is removed from the ski.

2. An annunciator as claimed in claim 1, wherein the switch means is a pressure-operated switch suitable for mounting on a ski, located so as to be under the sole of a boot fitted to the ski.

3. An annunciator as claimed in claim 1, wherein the switch means is a pressure-operated switch suitable for mounting on a ski so located as to be in contact with the front portion of the sole of a boot fitted to the ski.

4. An annunciator as claimed in claim 1, wherein the switch means includes a member with magnetically-operated switch contacts and an operating magnet suitable for mounting on a spring-loaded brake on a ski, so located that the member with the switch contacts lies close to the operating magnet when the ski-brake is held non-operative and the member with the switch contacts is remote from the magnet when the ski-brake is free and operative.

5. An annunciator as claimed in claim 2, wherein the annunciator includes a body portion located at one end of a generally rectangular plate member, and the pressure-operated switch is located at the other end of the plate member.

6. An annunciator as claimed in any one of claims 1 to 5, wherein the transmitter includes a sound generator.

7. An annunciator as claimed in claim 6, wherein the sound generator is so positioned that, when the annunciator is fitted to a ski, the output port of the sound generator lies a short distance above the ski in an open reverberation cavity bounded on one side by the ski.

8. An annunciator as claimed in claim 6 or claim 7, wherein the sound generator is electrically powered.

9. An annunciator as claimed in claim 6 or claim 7, wherein the sound generator is gas powered.

10. An annunciator as claimed in any one of claims 1 to 9, wherein the control means is arranged to provide interrupted operation of the transmitter.

11. An annunciator as claimed in any one of claims 1 to 10, wherein the control means includes delay means for providing a delay before the transmitter operates.

12. An annunciator as claimed in claim 11, wherein the delay is several seconds.

13. An annunciator as claimed in any one of claims 1 to 11 which further includes a manually operable arming switch.

14. An annunciator as claimed in any one of claims 1 to 13, and including theft alarm control means arranged, after activation, to detect movement of the annunciator and to switch on the transmitter when movement is detected, and means for activating the theft alarm control means.

15. An annunciator as claimed in claim 14, wherein the theft alarm control means is arranged to distinguish between short-term movement, consistent with accidental disturbance, and prolonged movement, consistent with deliberate removal.

16. An annunciator as claimed in claim 15, wherein the theft alarm control means includes delay means arranged to provide a delay period and the theft alarm control means is arranged not to switch on the transmitter before the end of the delay period, when movement is detected.

170 An annunciator as claimed in any one of claims 14 to 16, wherein the means for activating the theft alarm control means is a removable key which activates the theft control means on removal.

18. An annunciator as claimed in claim 17, wherein the key is arranged as a tab having a plurality of teeth extending from a backbone.

19. An annunciator as claimed in claim 18, wherein the key includes a magnet on a tooth as the means of identifying the key to the theft alarm control means.

20. A ski including an annunciator as claimed in any one of claims 1 to 19.