FR2458811A1 - SPEED INDICATOR FOR BICYCLES AND VELOMOTORS - Google Patents

Abstract

A.SPEED INDICATOR IN PARTICULAR FOR BICYCLES AND MOTORCYCLES, IN WHICH THE MEASUREMENT IS DONE BY MEANS OF A RELAY WITH A MOBILE TAB 6 FIXED TO A FIXED PART AND PERMANENT MAGNETS 4 FIXED TO ONE OF THE WHEELS. B. CHARACTERIZED IN THAT THE PERMANENT MAGNETS 4 ARE MOLDED IN AN ANNULAR MAGNET HOLDER 3 AT REGULAR INTERVALS, AND IN THAT THE MAGNET HOLDER 3 IS PROVIDED WITH FIXING MEANS ALLOWING IT TO ATTACH TO THE RAYS 2 ON THE EXTERIOR SIDE OF THE WHEEL 1. C. DEVICE APPLICABLE TO BICYCLES AND MOTORCYCLES.

Description

The invention relates to a speedometer

  for bicycles and mopeds, and more specifically an indica-

  speedometer of the type in which the measurement is made by means of a movable tongue relay mounted on a fixed part of the bicycle or moped, and of a certain number of permanent magnets fixed to one of the wheels, the magnets thus passing in front of the relay with movable tab during the rotation of the wheel. U.S. Patent No. 3,898,563 discloses a speed indicator of the above type in which the permanent magnets are attached to the spokes of the wheel.

  presents a number of disadvantages. One of these drawbacks

  is that the mounting of magnets can be difficult, another disadvantage being related to the fact that it is difficult to fix

  the magnets in place with precise reciprocal intervals.

  In addition, the number of magnets is determined in

  a certain measure by that of the rays.

  The object of the invention is to create a speedometer which does not have the above disadvantages of the art

prior.

  For this purpose, the speedometer according to the invention

  tion is characterized in that the permanent magnets are

  in an annular magnet carrier at regular intervals, and in that the magnet carrier is provided with fixing means

  to attach to the spokes on the outer side of the wheel.

  This arrangement makes it possible to set up a suitable, and in part arbitrary, number of magnets with precise mutual intervals; moreover, this arrangement makes very simple the operation of assembly or replacement of a set

magnets.

  According to another characteristic of the invention, the magnet carrier is fixed by means of a two-part ring mounted so as to be fixed at the same time as the magnet-holder

  ring around the spokes of the wheel.

  This method of assembly is the most advantageous.

  Finally, according to a last characteristic of the invention, the annular bearing and the two-part ring are made of a synthetic material, this material

  being particularly well adapted to the desired purpose.

  The invention will be better understood on reading the

2.- 2458811

  detailed description which follows and which refers to the drawings

  joints in which: - Figure 1 shows a speedometer according to the invention mounted on a bicycle, - Figure 2 shows a schematic arrangement of the reader of the speedometer according to the invention, - Figure 3 represents the position of the permanent magnets; FIG. 4 represents a section along the line IV-IV of FIG. 3; FIG.

magnet holder.

  Figure 1 shows the speedometer se-

  the invention mounted on a bicycle. On the spokes 2 of the front wheel 1 is fixed an annular disc 3 in which are molded seven permanent magnets 4. On the front fork 5 is fixed a reader 6, this reader comprising a relay tab

  mobile connected by a wire 7 to a reading instrument

8 mounted on the handlebar 9.

  Referring to Figure 2 which represents a schematic

  the speedometer reader layout

  according to the invention, a relay with movable tab 6 is placed suf-

  close to the moving magnets 4 so that the magnetic field

  that produced by them momentarily closes the relay languet-

  mobile when the rotating magnets pass the relay. This relay with movable tab is connected to a current source consisting for example of a standard dry cell of 4.5 volts, and two resistors 10 and 11, the signals produced at the

  output terminal 12 thus having the shape of pulses 13.

  The output terminal 12 is connected to a conventional measuring circuit

  contained in the reading instrument cabinet 8.

  The precise position of the magnets 4 on the disc

  nular 3 is shown in Figures 3 and 4.

  Referring to FIG. 5, the annular disk 3 is securely fixed around spokes 2 of the wheel by means of

  associated part 14, this associated part 14 being constituted

  two halves screwed together with the annular disc 3.

  The reader 6 is fixed to the front fork 5 by means of a collar

  bind ordinary fixation 15, but can also mount

  on a base plate attached to the wheel hub bolt.

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  the invention is not limited to the example of

  seven permanent magnets, described here. Indeed, this number of magnets is suitable for a wheel of 66 cm in diameter,

  but we can use a larger number or a smaller number

  magnets respectively for larger wheels or

  smaller diameters. The number of permanent magnets used

  in this preferred embodiment has been chosen

  so that a record of 1 km / h corresponds approximately

  at 1 pulse per second. It is obvious, however, that

  the measuring pulses of the speedometer can also

  can be used to produce feed pulses.

  an odometer placed in the instrument box.

reading 8.

245881t 4.-

R EV E N D I C A T I 0 N S

  1.- Speedometer especially for bicycles

  and mopeds, in which the measurement is made by means of a

  mobile tongue leash (6) fixed to a fixed part and permanent magnets (4) fixed to one of the wheels, characterized in that

  the permanent magnets (4) are molded in an annular magnet holder

  nular (3) at regular intervals, and in that the holder

  magnets (3) is provided with fastening means enabling it to

  attach to the spokes (2) on the outside of the wheel (1).

  2. Speedometer according to claim 1, characterized in that the magnet carrier (3) is fixed by means of a two-part ring (14) mounted to be fixed at the same time as the magnet carrier ring (3) around

spokes (2) of the wheel (1).

  3.- Speedometer according to one of the claims

  cations 1 and 2, characterized in that the annular magnet carrier (3) and the two-part ring (14) are made of synthetic material.