GB2060370A - Rods and walking sticks - Google Patents

Abstract

A rod or walking stick (1) provided with an electrical circuit comprising an electrically operable visual warning device (13) and an electrically operable audiable warning device (24) energizable from a source of electrical potential (14) by way of switch means (25), the circuit being arranged so that the audible warning device does not operate if the visual warning device fails to operate. The warning device may comprise two spaced lamps which are intermittently energised and a buzzer. <IMAGE>

Description

SPECIFICATION Rods and walking sticks This invention relates to rods and walking sticks and has an important appiication to rods and walking sticks for use by blind persons or persons with impaired eyesight.

It is an eccepted practice for blind persons and persons with impaired eyesight to carry a white walking stick or rod so that other road users will be made aware of the blind persons's disability and make due allowance for it. Thus pedestrians can give precedence to a blind person walking on a pavement and thus avoid a collision, while motorists and drivers of other vehicles can give extra consideration to the blind person at pedestrian crossings or at crossroads and thus prevent an accident. However, it is a disadvantage of such white walking sticks or rods that in inclement weather, such as rain, snow or mist, or in the hours of darkness, when visibility is reduced below normal, other road users may fail to notice the white stick of the blind person.

An object of this invention is to provide a rod or walking stick which mitigates this disadvantage.

According to the present invention a rod or walking stick is provided with an electrical circuit comprising an electrically operable visual warning device and an electrically operable audible warning device energisable from a source of electrical potential by way of switch means, the circuit being arranged so that the audible warning device does not operate if the visual warning device fails to operate.

Preferably, the rod or walking stick has a further visual warning device energizable from the source of electrical potential by way of the switch means, the circuit being arranged so that the audible warning device does not operate if both visual warning devices fail to operate.

Conveniently, the visual warning device and the audible warning device are arranged to be energized intermittently when the switch means is operated.

For example, the visual warning device and the audible warning device may be energized between 60 and 120 times per minute when the switch means is operated.

The rod or walking stick may comprise a tubular metal casing which forms an electrical conductor of the electrical circuit and may have an outer surface which is predominantly white.

The audible warning device may be an electric buzzer and the or each visual warning device may be a filament lamp.

The rod or walking stick may include logic circuit means arranged to monitor the operation ofthevis- ual warning device(s) and to inhibit the operation of the audible warning device when all the visual warning devices fail to operate.

The source of electrical potential may comprise one or more rechargeable batteries and the rod or walking stick may be provided with a socket arranged to receive a plug for charging the battery or batteries.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings.

Figure 1 is a longitudinal section of a walking stick in accordance with the invention; and Figure 2 is a schematic circuit diagram of the electrical components incorporated in the walking stick shown in Figure 1.

Referring in the first instance to Figure 1, the walking stick 1 comprises a hollow tubular member 2 of aluminium alloy of substantially eighty centimetres in length and substantially sixteen millimetres in outside diameter. The lower end 3 of the tubular member 2 is closed by a rubber grommet 4while the upper end 5 is provided with an external screw thread 6. A hollow cylindrical chamber 7 of aluminium alloy, which is provided with an internal screw thread 8 at its lower end 9 is screwed on to the upper end 5 of the tubular member 2. The outer surface of the tubular member 2 is coated with white paint.

Two lamp holders .10 are mounted within the tubular member 2 at spaced positions adjacent respective windows 11 of transparent plastics material inserted into the wall 12 of the tubular member 2.

Two electrical filament lamps 13 inserted in the lamp holders 9 are arranged to shine through the windows 11 when energized from five rechargeable batteries 14 accommodated in the hollow cylindrical chamber 7.

The batteries 14 are arranged in series in a stack and a helical steel spring 15 connected to a terminal 16 in the lower end 9 of the chamber 7 engages the negative pole 17 of the lowermost battery 14 in the stack and affords electrical connection therewith.

The spring 15 is arranged to urge the batteries 14 upwardly, so that the positive pole 18 of the uppermost battery 14 in the stack engages a terminal 19 at the upper end of the chamber 7.

A hollow housing 21 of aluminium alloy 21 having an internal screw thread 22 is screwed onto the externally screw threaded upper end 23 of the chamber7 and accommodates an electric buzzer 24 which is energizable from the batteries 14. A push button switch 25 mounted in the uppermost wall 26 of the housing 21 is arranged to connect the buzzer 24 to the batteries 14. A horizontally disposed handle 27 comprising a tubular member 28 enclosed by a rubber hand grip 29 is secured to the housing 21 by an externally screw threaded end portion 30 on the tubular member 28 which screws into an internal screw thread 31 on the housing 21.

The end 32 of the handle 27 remote from the housing 21 is provided with an aperture 33 affording access to a socket 34 arranged to receive a plug (not shown) for charging the batteries 14. A printed circuit board 35 accommodated in the handle 27 carries the electronic components of a logic circuit 36 arranged to control the energization of the electric lamps 13 and the electric buzzer 24. The logic circuit 36 ensures that the electric buzzer 24 does not oper ate unless at least one of the lamps 13 is operating and also controls the frequency of intermittent ener gization of the lamps 13 and the buzzer 24, typically between 60 and 120 times per minute.

As can be seen in Figure 2 the logic circuit 36 com prises two NPN transistors having their collector electrodes connected to one terminal of each of the lamps 13 and also connected by way of a resistor 39 to the base electrode of a further transistor 40. The emitter electrode of transistor 37 is connected to the base electrode of transistor 38 which has its emitter electrode connected to the negative pole ofthe lowermost battery 14. The base electrode of transistor 40 is also connected to the negative pole of the lowermost battery 14 by way of a resistor 41. The collector electrode of the transistor 40 is connected to one terminal of the buzzer 24 which is shunted by a capacitor 42.

The logic circuit also includes four two-input NAND gates 43,44,45 and 46 each of which has its input terminals strapped together. The NAND gates 44,45 and 46 are connected to a resistor/capacitor network formed by resistors 47. and 48 and capacitor 49 so that they function as a multivibrator operating at a repetition rate within the range 60 to 100 times a minute. The output of NAND gate 44 and the strapped inputs of NAND gate 43 are connected to the base electrode of transistor 37 by way of a resistor 50.

The emitter electrode of transistor 40 is connected to the negative pole 17 of the lowermost battery 14 in the stack while the positive pole 18 of the uppermost battery 14 in the stack is connected by way of the push button switch 25 to the other terminal of the two lamps 13, the capacitor 42 and the buzzer 24.

The socket 34 is connected across the batteries 14 while the switch 25 and the batteries 14 are shunted by a capacitor 51.

The circuit arrangement described above operates in the following manner. When the push button switch 25 is closed the lamps 13 and the buzzer 24 are energized intermittently at a repetition rate within the range 60 to 120 times per minute which is governed by the values of the resistor/capacitor network formed by resistors 47 and 48 and capacitor 49. Therefore, while at least one of the lamps 13 is flashing at this repetition rate the buzzer will also be operated at the same repetition rate. However, if both lamps 13 fail to flash the current flowing through the resistors 39 and 41 modifies the potential applied to the base of transistor 40 so that the current supplied to buzzer 24 through the collector of thetransistor40 is no longer sufficient to operate the buzzer 24.

It will be appreciated that if the lamps 13 fail to flash and therefore fail to provide a visual warning, the failure of the buzzer 24 to operate will alert the person operating to this situation even though he is blind and cannot see the lamps. This is an important safety factor for the blind person. Provided that one lamp 13 is flashing the buzzer will, of course, operate.

When the voltage available from the batteries falls to an unacceptable level they may be recharged by a plug inserted in the socket 34. The aperture 33 in the end 32 of the handle 27 through which the plug is inserted is in a position which can be readily located by a blind person. The plug can be of the type which operates from a rectifier of the kind used for electronic calculators and can be energized from the mains voltage.

Although the embodiment of the invention described above has two lamps 13, it will be appreciated that other embodiments of the invention could be provided with three or more lamps, or alternatively could be provided with a single lamp 13. Moreover, although the lamp or lamps 13 have been described as energized intermittently they could of course be energized continuously when the switch 25 is closed.

Although reference numerals have been used in the appended Claims to improve the intelligibility of these Claims, it is expressly stated that these reference numerals should not be construed as limiting the Claims to the constructions illustrated in the accompanying drawings.

Claims (14)

1. A rod or walking stick (1) provided with an electrical circuit comprising an electrically operable visual warning device (10) and an electrically operable audible warning device (24) energizable from a source of electrical potential (14) by way of switch means (25), the circuit being arranged so that the audible warning device does not operate if the visual warning device fails to operate.

2. A rod or walking stick as claimed in Claim 1, having a further visual warning device (10) energizable from the source of electrical potential (14) by way of the switch means (25), the circuit being arranged so that the audible warning device does not operate if both visual warning devices fail to operate.

3. A rod or walking stick as claimed in Claim 1 or Claim 2, wherein the visual warning device and the audible warning device are energized intermittently when the switch means is operated.

4. A rod or walking stick as claimed in Claim 3, wherein the visual warning device and the audible warning device are energized between 60 and 120 times per minute when the switch means is operated.

5. A rod or walking stick as claimed in any preceding claim, including logic circuit means arranged to monitor the operation of the visual warning device(s) and to inhibit the operation of the audible warning device when all the visual warning devices fail to operate.

6. A rod or walking stick as claimed in any preceding claim, comprising a tubular metal casing which forms an electrical conductor of the electrical circuit.

7. A rod or walking stick as claimed in any preceding claim, having an outer surface which is predominantly white.

8. A rod or walking stick as claimed in any preceding claim, wherein the audible warning device is an electric buzzer (24).

9. A rod or walking stick as claimed in any preceding claim, wherein the or each visual warning device is a filament lamp (10).

10. A rod or walking stick as claimed in any preceding claim, wherein the source of electrical potential comprises one or more rechargeable batteries.

(14).

11. A rod or walking stick as claimed in Claim 10, provided with a socket (34) arranged to receive a plug for charging the battery or batteries (14).

12. Arod or walking stick as claimed in any preceding claim, wherein the switch means comprises a push button switch (25).

13. A rod or walking stick constructed substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

14. A rod or walking stick as claimed in any preceding claim having an electrical circuit substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.