WO1996030721A2

WO1996030721A2 - Revolutions counting apparatus

Info

Publication number: WO1996030721A2
Application number: PCT/GB1996/000803
Authority: WO
Inventors: Howell Roberts
Original assignee: Dcs Rentals Limited
Priority date: 1995-03-31
Filing date: 1996-04-01
Publication date: 1996-10-03
Also published as: WO1996030721A3; GB9506701D0

Abstract

A revolutions counting apparatus for a golf-trolley wheel (4) includes a tilt switch device (5) comprised of two tilt switches anchored to the wheel (4) at an angular spacing of 90°, so that there is no need for a fixed reference point. The wheel (4) and the device (5) can constitute an independently mountable unit. The apparatus includes control circuitry which emits counting signals only once both tilt switches have operated in a predetermined manner, particularly both been continuously in a closed state for a predetermined time and been continuously in an open state for a predetermined time.

Description

IMPROVEMENTS IN OR RELATING TO REVOLUTIONS -COUNTING APPARATUS

This invention relates to revo lu ions -coun ing apparatus .

It is known to provide gravity switches for various angle-measuring purposes. GB-A-2155691 discloses a mercury switch to measure the angle of rotation of an aircraft or the angle of a surface. The switch comprises a hollow, circular tube containing mercury and groups of electrical contacts. GB-A-959663 discloses a similar form of mercury switch that measures the angle of rotation of a rocking shaft of a conveyor belt load indicating apparatus. GB-A- 1457662 discloses two tilt switches of a ball-in-tube form- operated when a spool carrier swivels out of its normal position. GB-A-1077164 discloses a bank of mercury switches which measure the angles of rotation of rotatable discs of a weighing machine. WO-A-88/00329 discloses use of a mercury switch to measure angle of tilt of a tractor, for example.

It is known to measure the distance travelled by a golf-trolley by counting whole or part revolutions of one of its wheels. EP-A-04929266 discloses a system of a rotation sensor, for example an electrical dynamo, built into a hub unit of a trolley wheel, which may be used to replace an existing trolley wheel, and coupled by electrical cable to a digital LCD display on the trolley handle, to give a read¬ out of the distance travelled and/or remaining to be travelled to each a given hole of a golf course GB-A-2125349 describes a trolley with a magnet on a wheel to actuate a need switch, which may be fixed to a frame of the trolley, generating pulses which are fed by cable to a microprocessor and display on the handie. EP-A-0281846 discloses a system similar to GB-A-2125349 but using an opto-electronic emitter and detector pair, or a magnet and Hall-effect sensor, to measure rotation. US-A-4887281 discloses a unit for retro- fitting to a golf trolley or cart, with respectively two or three, magnets on the wheel and Hall sensor fixed to the frame. An electrical cable links the sensor to a display on the dashboard or a handle, respectively. US-A-4879732 describes a portable, self-contained odometer attachable to a golf trolley and intended to receive one pulse per revolution of a trolley wheel and capable of being programmed for size of wheel. Other devices for measuring the number of rotations of a wheel by pulse-producing switches are known. GB-A-1449371 discloses a system for using on motor vehicles comprising a magnet on a rotary shaft operating two fixed reed switches arranged in a cross formation to produce pulses used to indicate speed and distance travelled. GB-A-1336246 discloses use of a magnet fixed to a wheel and a reed switch fixed to a frame in measurement of distance travelled by a pipeline pig using a wheel on a spring area to enage the pipe. GB-A-1315933 discloses a similar arrangement for measuring length. GB-A-1161984 discloses the use in a tachometer of an odometer in which the revolutions of a shaft are measured using a pair of magnets and associated need switches. US-A-4352063 uses a magnet/coil arrangement on a bicycle fork to count the spokes of a rotating wheel by induction of a pulse in the coil. GB-A-2059595 discloses a similar system of counting wheel spokes, as well as an alternative system employing a magnet attached to the wheel.

EP-A-0431243 discloses a magnet on a cycle wheel spoke and a need switch on the front fork measuring revolutions of the wheel and communicating, by way of a wireless link, with a display unit detachably mounted on a handlebar. Speed and distance travelled are displayed on the unit. Similar wireless transmitt ing-receiving systems for bicycles are disclosed in EP-A-0402620 and US-A-5008647. According to one aspect of the present invention, there is provided revolutions-counting apparatus consisting of a rotary object, control circuitry, a tilt switch device carried by said rotary object so as to rotate therewith and to open and close in dependence upon the number of revolutions rotated by the rotary object, said control circuitry serving to receive counting signals produced by said tilt switch device.

Owing to this aspect of the invention, and particularly owing to the use of a tilt switch device, it is possible to produce a revolutions-counting apparatus in which there is no fixed reference point, i.e. a reference point fixed relative to supporting means for the rotary object, and thus no need to attach part of the switch device to the supporting means.

According to a second aspect of the present invention, there is provided revolutions-counting apparatus comprising a rotary object, detecting means arranged to detect the number of revolutions rotated by said object, and mounting means mounting said object for rotation relative to said mounting means, the whole of said detecting means being carried by said object so as to rotate therewith.

Owing to this aspect of the present invention, the rotary object and the whole of the detecting means can constitute a unit which can be handled as such, thus avoiding the need to attach part of the detecting means to the mounting means and to align such part relative to the remaining part of the detecting means on the rotary object. According to a third aspect of the present invention, there is provided revolutions-counting apparatus comprising a rotary object, control circuitry, switch means included in said control circuitry, a plurality of switch-operating means arranged to open and close said switch means in dependence upon the number of revolutions rotated by the rotary object, said control circuitry serving to emit counting signals only once said plurality of switch- operating means have operated said switch means in a predetermined manner. Owing to this aspect of the invention, it is possible to mitigate the emission of false counting signals caused by unwanted opening and/or closing of only a single switch- operating means.

The plurality (which is preferably two, but may be more) of switch-operating means may be arranged to operate a single switch means or respective switch means. The switch- operating means may take the form of mercury in a tilt switch. According to a fourth aspect of the present invention, there is provided revolutions-counting apparatus comprising a rotary object, control circuitry, switch means included in said control circuitry and arranged to open and close in dependence upon the number of revolutions rotated by said object, said control circuitry serving to emit a counting signal only once said switch means has both been continuously in a closed state for a predetermined time period and been continuously in an open state for a predetermined time period.

Owing to this aspect of the present invention, it is possible to mitigate the emission of false counting signals caused by momentary closing or opening of the switch means. According to a fifth aspect of the present invention, there is provided revolutions-counting apparatus including an electrical transmitter arranged to transmit counting signals of a predetermined character, and electrical modulating means arranged to modulate said signals at a predetermined accurate modulation characteristic. Owing to this aspect of the present invention, it is possible to minimise interference among the counting signals transmitted by the transmitters of various revolutions- counting apparatus within transmission range of each other. This aspect is particularly applicable to revolutions- counting apparatus on golf trolleys, for example.

The counting signals may be radio signals of a predetermined frequency, which are modulated at a predetermined accurate frequency, or may be infra-red signals, which are subjected to pulse code modulation (PCM) . According to a sixth aspect of the present invention, there is provided, in combination, a golf trolley, a revolutions-counting apparatus carried by said trolley for counting the number of revolutions rotated by a wheel thereof, electrical transmitting means connected to said apparatus for radiating counting signals, electrical receiving means remote from said trolley for receiving said counting signals and display means remote from said trolley and connected to said receiving means for displaying information representative of said number of revolutions.

Owing to this aspect of the present invention, the golfer can continue to read the display means even at some distance from the trolley. In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawings in which :-

Figure 1 is a diagrammatic side perspective view of a wheel and a self-contained version of the odometric apparatus associated with the wheel.

Figure 2 is a diagrammatic side perspective view of a golfer pulling a golf trolley and remote version oαometric apparatus associated with the trolley.

Figure 3 is a diagrammatic side elevation of two tilt switches of the odometric apparatus.

Figure 4 is a block diagram of electrical circuitry of detecting and displaying unit of a self-contained version of the odometric apparatus.

Figure 5 is a block diagram of electrical circuitry of a detecting and transmitting unit of a remote version odometric apparatus.

Figure 6 is a block diagram of electrical circuitry of a receiving and displaying unit of a remote version of the apparatus, and Figure 7 is a block diagram of electrical circuitry of a detecting and displaying unit of an alternative self- contained version of the odometric apparatus.

Referring to Figure 1, the wheel 2 has a self-contained unit 1 affixed whereby the revolutions of the wheel are detected and displayed. This display may be in the form of linear distance travelled or number of revolutions.

Figure 2 shows a golf trolley 3 having two ground wheels 4 to one of which is fixed a unit 5 whereby the revolutions of the wheel are detected and transmitted. Mechanically independent of the trolley 3 and the unit

5 is a receiving and display unit 6 which may be carried by golfer G.

The units 1 and 5 include two tilt switches 7 and 8 (Figure 3) in the form of respective mercury gravity switches which are so fixed in the units 1 and 5 that their respective longitudinal axes L are always at 90o to each other. Moreover, the unit 1 or 5 is so attached to the wheel that the longitudinal axes L lie in a substantially vertical plane containing the axis of rotation of the wheel. The direction of rotation of the switches 7 and 8 about the axis A is indicated by the arrow R. Each switch has a pair of contacts 9 at one end thereof closable by a globule of mercury 10.

Referring to Figure 4, the switches 7 and 8 are connected to respective "closed" timers 11 and 12 which are connected to respective voltage threshold circuits 13 and 14, which may be in the form of digital amplifiers, which produce respective outputs only once the respective switches

7 and 8 have continuously occupied their "closed" states for predetermined time periods, for example 20mS. The circuits 13 and 14 are connected to respective "open" timers 15 and 16 which are connected to a common bi-stable circuit 17 having a voltage threshold capability whereby respective outputs are emitted only if the respective switches 7 and 8 have continuously occupied their "open" states for a predetermined time period, for example 20mS. The switch 7 is connected to the "set" input of the bi-stable circuit 17 and the switch 8 is connected to the "reset" input of the circuit 17. The circuit 17 emits a counting signal only if it has received one "set" signal followed by one "reset" signal .

The counting signal emitted by the circuit 17 triggers a pulse oscillator 18. The output of the oscillator 18 is gated by means of a manually adjustable pulse selector 19 so as, upon energisation by the circuit 17, to produce a selected number of counting pulses, depending upon the circumference of the wheel. The pulse train emitted by the oscillator 18 is then divided by ten in a divider 20 which operates a counter 21 which is connected to a display 22 which displays the total number of pulses generated from a zero setting, with the interposition of a decimal point generated by a generator 23.

The counter 21 is provided with a reset facility 30 to reset itself and the display 22 to zero. This reset facility may be remote from the unit 1 and operated by such means as infra-red or ultra-sonic transmitter/receiver in order to save the user from having to reach the unit 1 itself each time a reset to zero is required - for example at the start of each new hole on a golf course.

In use, the user programmes the wheel size into the pulse selector 19 and sets the counter 21 and the display 22 to zero. He can then drive from the tee, walk to the ball with his trolley, and thereby measure the distance driven. The counting effects described herein function whichever direction the wheel rotates. In this way, when the apparatus is attached to a golf trolley wheel, it would not matter whether the user pushed or pulled the trolley, nor to which wheel the apparatus is attached. The display may be set at an angle of, say, 45° to the vertical plane to facilitate reading of the display from a standing position. There can be a facility for decremental measuring instead of or additional to incremental measuring, so that the golfer can programme in the distance from the tee to the pin or to the front of the green, for example, and the distance remaining to the pin or the front of the green be displayed. The arrangement of the two tilt switches 7 and 8 obliquely relative to each other in a substantially vertical plane, combined with the circuitry 11 to 17, is employed to overcome the false counting which could otherwise arise when a single tilt switch has its longitudinal axis in a substantially horizontal condition and thus the switch is in an unstable state, in which condition vibration can cause several "make-and-break" cycles of the switch.

Referring to Figures 5 and 6 in the drawings, these show an enhanced version of the unit whereby the counting and display circuitry are remote from the rotation detection circuitry. In this case, the counting signal emitted by the circuit 17 triggers a timer 24 which energises a radio transmitter 25 for a predetermined time period, for example 50mS . The transmitter 25 sends a carrier burst at a suitable frequency, for example 418Mhz, for that predetermined time period, but a modulator 26 in the form of a crystal generator modulates the transmitter's carrier with an accurate frequency, for example 32.768khz, which differs sufficiently from differing modulating frequencies of respective odometric apparatus of other users within transmission range to avoid interference.

Referring to Figure 6, the transmitted counting signal is received by a radio receiver 27 of the unit 6 (Figure 2) .

The output from the receiver 27 is input into a filter 28 tuned to the particular modulating frequency in question, for example 32.768khz. The filter output is fed to an electronic switch 29 which is connected to a pulse oscillator 18 and serves, upon receiving the counting signal, to enable the pulse oscillator 18 for a predetermined time period, for example 50mS. The circuitry from here to the display is as described above for the self- contained unit. The use of wireless transmission has the advantage that the unit 5 can be freely attached to the wheel without the need for such things as slip-rings, and that the unit 6 can be remote from the trolley. Instead of a radio transmission occurring for each revolution of the wheel, the number of revolutions could be 'stored' in the unit and transmitted only upon request by the remote user to update the remote counter and display. This would have the advantage of further reducing the possibility of interference with other similar units as the amount of 'airtime' is substantially reduced. Also, a transmission could be sent once per yard or metre instead of once per revolution. This would make the design of the receiver simpler and therefore smaller and lighter.

In Figure 7 the electrical circuitry and associated components are replaced by an application specific integrated circuit, in this instance a microcontroller (31) PIC16C54. The microcontroller 31 can be any of a number that are commercially available, and comprises a microprocessor with inbuilt memory and input/output circuitry all pre- configured to carry out the specific task. It is also possible to use a microcontroller that incorporates circuitry to drive a liquid crystal display (LCD) 22 thereby eliminating the need for external display drivers 32.

The microcontroller 31 is programmed at manufacture to process the input from the tilt switches 7,8 in response to the rotation (R) of the wheel 2 or 4 and to process the input from a keypad 33 for a user. The keypad 33 is used to enter the circumference of the wheel 2 or 4 before use and then can also be used to enter data, e.g. the distance of a particular hole. The display 22 is incremented with each revolution of the wheel 2 or 4, or, if a preset distance has been entered, the display 22 is decremented with each revolution of the wheel 2 or 4. The microcontroller is powered from batteries 34 and has an "on" switch 35.

The odometric apparatus can be employed to monitor slowly rotating objects of almost any description, for example it is particularly applicable to a wheel of an agricultural vehicle for measuring the size of fields, for example. For some uses, the display can show the number of rotations rather than the linear distance measured.

The odometric apparatus could also contain a speech synthesiser instead of or in addition to a display so that the distance travelled or number of revolutions could be transmitted audibly. This would be useful in applications where the user is poorly sighted or where light levels are very low.

Although the use of tilt switches is preferred, the apparatus could employ another method of detecting rotation, for example a light-responsive device included in the unit 1 or 5 and arranged, as the unit 1 or 5 rotates with the wheel, to point alternately to the ground and to the sky. Alternatively, the unit could comprise a device (a flux-gate compass) that detects rotation relative to the earth's magnetic field. Another possibility is for the rotation- detecting means to be partly upon the wheel and partly upon the wheel mounting, for example the trolley frame, when such systems as infra-red detection, mechanical contact, Hall- effect transistors and magnetic sensors could be employed.

Claims

1. Revolutions-counting apparatus consisting of a rotary object (2,4), control circuitry (11-17/31), a tilt switch device (7,8) carried by said rotary object (2,4) so as to rotate therewith and to open and close in dependence upon the number of revolutions rotated by the rotary object (2,4), said control circuitry (11-17_/31) serving to receive counting signals produced by said tilt switch device (7,8) .

2. Apparatus according to claim 1, wherein detecting means (7,8) arranged to detect the number of revolutions rotated by said object (2,4) comprises said tilt switch device (7,8) and the whole of said detecting means (7,8) is carried by said object (2,4) so as to rotate therewith.

3. Apparatus according to claim 2, wherein the rotary object (2,4) and the whole of the detecting means (7,8) constitute a unit which can be handled as such.

4. Apparatus according to any preceding claim, wherein said tilt switch device (7,8) includes switch means (9) included in said control circuitry (11-17/31) and a plurality of switch-operating means (10) arranged to open and close said switch means (9) in dependence upon the number of revolutions rotated by the rotary object (2,4), said control circuitry (11-17/31) serving to emit counting signals only once said plurality of switch-operating means (10) have operated said switch means (9) in a predetermined manner.

5. Apparatus according to claim 4, wherein said plurality of switch-operating means (10) are arranged to operate a single switch means.

6. Apparatus according to claim 4, wherein said plurality of switch-operating means (10) are arranged to operate respective switch means (9) .

7. Apparatus according to any preceding claim wherein said control circuitry (11-17/31) serves to emit a counting signal only once said tilt switch device (7,8) has both been continuously in a closed state for a predetermined time period and been continuously in an open state for a predetermined time period.

8. Apparatus according to any preceding claim, and further comprising an electrical transmitter (25) arranged to transmit counting signals of a predetermined character, and electrical modulating means (26) arranged to modulate said signals at a predetermined accurate modulation characteristic .

9. Apparatus according to claim 8, wherein said transmitter (25) is arranged to emit counting signals of a predetermined radio frequency, and said modulating means (26) is arranged to modulate said signals at a predetermined accurate modulation frequency.

10. Apparatus according to claim 8, wherein said transmitter is arranged to emit infra-red counting signals and said modulating means is arranged to perform pulse code modulation of said signals.

11. Apparatus according to any preceding claim, wherein said object (2,4) is a golf trolley wheel (2,4) .

12. In combination, a golf trolley (3) and a revolutions- counting apparatus according to any one of claims 1 to 7 and carried by said trolley (3) for counting the number of revolutions rotated by a wheel (2,4) thereof, electrical transmitting means (25) connected to said apparatus for radiating counting signals, electrical receiving means (27) remote from said trolley (3) for receiving said counting signals and display means (22) remote from said trolley (3) and connected to said receiving means (27) for displaying information representative of said number of revolutions.

13. Revolutions-counting apparatus comprising a rotary object (2,4), detecting means (7,8) arranged to detect the number of revolutions rotated by said object (2,4) , and mounting means mounting said object (2,4) for rotation relative to said mounting means, the whole of said detecting means (7,8) being carried by said object so as to rotate therewith.

14. Apparatus according to claim 13, wherein the rotary object (2,4) and the whole of the detecting means (7,8) constitute a unit which can be handled as such.

15. Revolutions-counting apparatus comprising a rotary object (2,4), control circuitry (11-17_/31), switch means (9) included in said control circuitry (11-17_/31), a plurality of switch-operating means (10) arranged to open and close said switch means (9) in dependence upon the number of revolutions rotated by the rotary object (2,4), said control circuitry (11-17/31) serving to emit counting signals only once said plurality of switch-operating means (10) have operated said switch means (8) in a predetermined manner.

16. Apparatus according to claim 15, wherein said plurality of switch-operating means are arranged to operate a single switch means.

17. Apparatus according to claim 15, wherein said plurality of switch-opera ing means (10) are arrj-nged to operate respective switch means (9) .

18. Revolutions-counting apparatus comprising a rotary object (2,4), control circuitry (11-17_/31), switch means (9) included in said control circuitry (11-17_/31) and arranged to open and close in dependence upon the number of revolutions rotated by said object (2,4) , said control circuitry (11-17/31) serving to emit a counting signal only once said switch means (9) has both been continuously in a closed state for a predetermined time period and been continuously in an open state for a predetermined time period.

19. Revolutions-counting apparatus, including an electrical transmitter (25) arranged to transmit counting signals of a predetermined character, and electrical modulating means

(26) arranged to modulate said signals at a predetermined accurate modulation characteristic.

20. Apparatus according to claim 19, wherein said transmitter (25) is arranged to emit counting signals of a predetermined radio frequency, and said modulating means

(26) is arranged to modulate said signals at a predetermined accurate modulation frequency.

21. Apparatus according to claim 19, wherein said transmitter is arranged to emit infra-red counting signals and said modulating means is arranged to perform pulse code modulation of said signals.

22. In combination, a golf trolley (3) , a revolutions- counting apparatus carried by said trolley (3) for counting the number of revolutions rotated by a wheel (.2,4) thereof, electrical transmitting means (25) connected to said apparatus for radiating counting signals, electrical receiving means (27) remote from said trolley (3) for receiving said counting signals and display means (22) remote from said trolley (3) and connected to said receiving means (27) for displaying information representative of said number of revolutions.