GB2208182A

GB2208182A - Body testing

Info

Publication number: GB2208182A
Application number: GB8815672A
Authority: GB
Inventors: Philip Swarbrick
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-07-08
Filing date: 1988-07-01
Publication date: 1989-03-08
Also published as: GB8716022D0; GB8815672D0

Abstract

A wheel 16 is rolled against a car body and, when the metal beneath the paint of the car body is sufficiently deep, and sufficiently close to the surface of the car body the magnetic force exerted between that metal and a magnet 12 causes the magnet to move in the left, against the action of a spring 28, to cause a contact arm 22 to move against a further contact 32. When the wheel moves over a portion of a vehicle where the metal is non-existent, or relatively thin, or spaced some distance from the surface of the vehicle, the magnetic force holding the magnet against the contact 32 is no longer sufficient to overcome the force of the spring 28 and the spring causes the magnet to be brought back to the position shown so that the contact arm abuts the contact 26 and the indication of the unsatisfactory state of the body is given. Various arrangements of magnets, springs and contacts are described together with means for adjustment of the spacing between the magnet and body. <IMAGE>

Description

BODY TESTING The present Invent Ion relates to a body tester and in particular, although not exclusively to a vehicle body tester, and to a method of testing the metal in a body.

In vehicles which are sold second hand, it Is common for parts of the body to have become rusted or damaged. Those pa-rts of the body are often not visible as a filler material Is used to repair the damaged or rusted area, with the filler having been sanded smooth and painted over. When a person Is considering buying such a second hand vehicle It is clearly in their Interest to know of the presence of any such filled areas.

According to one aspect of the present Invention, a body tester Includes a magnet and Indicating means arranged to provide an indication of a magnetic force, if any, exerted on the magnet. In use, the magnetic force is derived from the metal In a body adJacent to the tester. With such a tester an Indication may be given when the tester passes over an area of a vehicle body which has been filled and either the distance of the metal from the surface of the body exceeds a certain distance or there is no metal behind the surface, thus altering a potentlal purchaser to possible problem areas.

An additional advantage of the tester Is the use of a magnet which may allow no power to be consumed in order to derive a signal Indicative of the distance of metal from the magnet.

The magnet may be movably mounted on the tester and may be slideably mounted thereon. The movement of the magnet may be used to provide the Indicatlon of the magnetic force.

The magnet may be biased In one directlon of movement, and the magnetic force exerted on the magnet may be arranged to overcome that bias when metal in a body adjacent to the tester Is sufficiently close to the surface of the body.

The tester may be arranged to abut a body when testing that body. The tester may include a rotatable portion arranged to rlde over the surface of a body. In use, the magnetic force exerted between any metal In a body and the magnet may assist in holding the tester against the body.

The Indication means may be arranged to indicate when the force exerted on a magnet exceeds a predetermined amount.

According to another aspect of the present Invention, a method of testing the metal In a body comprises locating a body tester including a magnet adjacent to the body, and Indicating when the magnetic force exerted on the magnet falls below a predetermined amount. The method may further comprlse holding the tester In contact with the body, and may also comprise moving the tester over the body.

The invention may be carried into practice in various ways, but two embodiments will now be descrlbed by way of example and with reference to the accompanying drawings in which: Figure 1 is a side view with the cover removed of a first embodiment of a body tester; Figure 2 Is a wiring dlagram of the tester shown in Figure 1; Figure 3 is a view of the magnetic portion of an alternative embodiment of a tester; Figure 4 is a wiring diagram incorporated In the tester shown In Figure 3; Figure 5 Is a view of an alternative tester similar to that shown in Figure 1; Figure 6 is a view of a further embodiment of a tester similar to that shown In Figure 1; Figure 7 is a view of an alternative embodiment of a tester; Figures 8 and 9 are views of testers which include alternative means for adjusting the sensitivity of a tester;; Figure 10 Is a view of an alternative tester, and Figure 11 is a view of a further embodiment of a tester.

The tester shown in Figure 1 comprises a housing 10 In which Is mounted a magnet 12 supported by an arm 14. A rotatable rubber wheel 16 is mounted at the front of the tester, and a battery 18 is provided towards the rear of a housing. A switch 20 Is provided to power the circuit shown In Figure 2 from the battery 18. A contact arm 22 is pivotally mounted on a rod 24 and is biased In an antl-clockwlse directlon against a contact 26 by a spring 28. The contact arm 22 co-operates with a lip 30 formed on the rear of the arm 14 carrying the magnet 12 to bias the magnet Into the position shown.

In use, the wheel 16 Is rolled against a car body and, when the metal beneath the palnt of the car body is sufficiently deep, and sufficiently close to the surface of the car body, the magnetic force exerted between that metal and the magnet 12 causes the magnet to move to the left, when viewed in the figure, against the action of the sprlng 28 to cause the contact arm 22 to move against a further contact 32. In this position, the tester is sensing that there is sufficient metal sufficiently close to the surface of the vehicle for the proposed purchaser of the vehicle not to worry about the state of that part of the body.When the wheel is moving over a portion of the vehicle where the metal is non existent, or relatively thin, or spaced some distance from the surface of the vehicle, the magnetic force holding the magnet against the contact 32 Is no longer sufficient to overcome the force of the spring 28, and the spring then causes the magnet to be pulled back to the position shown, and the contact arm then abuts the contact 26. In this position, the prospective purchaser of the vehicle should be concerned about the state of that part of the vehicle body. The arm 14 on which the magnet 12 is located is gulded for movement by a spigot 34 extending through a slot 36 formed along the arm 14.

Instead of the wheel 16, a pad may be provided which slides over the surface of the vehicle.

In Figure 2, the two contacts 26 and 32 are shown, with the contact arm 22 being shown schematically.

In use, the switch 20 Is closed and, when the contact arm 22 abuts the contact 26, a circuit Is made between a positive supply 38 and a negative supply 40 through a red light emitting dlode 42 to Illuminate that diode and indicate that the vehicle body is not satisfactory In that region. When the contact arm 22 abuts the contact 32, the circuit Is made through a green diode 44, and the user Is aware that the vehicle body Is satisfactory in that region.

The voltage between the positive and negative supply is 3 volts.

In the embodiment shown In Figure 3, only the magnet 112, the supporting arm 114, a coil spring 128 and contacts 126 and 132 are shown, but it will be appreciated that the embodiment shown in Figure 2 can be incorporated Into a housing similar to that shown in Figure 1. The embodiment shown in Figure 3 operates In a similar manner to that shown In Figure 1, with the exception that the rear of the arm 114 includes a transverse contact arm 122 extending across the arm 114, the contact arm 122 abutting a pair of spaced contacts at either end of that arm in each extreme direction of movement. The contact arm 122 is made out of conductive material, and the operation of the circuit for the embodiment shown in Figure 3 Is shown In greater detail In Figure 4.

Referring now to Figure 4, in use, the switch 120 is closed and an amber light emitting diode 146 Is illuminated by belng connected to a positive voltage source 138 and an earth 140 via a resistor 148. The Illumination of the amber diode 146 indlcates that there is sufficient voltage for the device to operate. In this embodiment, the difference between the voltage across the positive and earth supply is 3 volts. When the contact arm abuts both of the contacts 126, a red diode 142 Is Illuminated, Indicating a possible problem area In the vehicle body being tested and the brightness of the amber diode 146 Is reduced somewhat.When the magnet is caused to move to the left, when viewed in the diagram, the contact arm abuts both of the contacts 132 and the green diode 144 is illuminated indicating that the vehicle body is satisfactory and a reductlon is made to the brightness of the amber dlode 146.

In Flgures 5 to 11 like parts to those shown in Figure 1 have been given the same reference numeral prefixed respectively by the numbers 2,3,4,5,6,7 and 8.

In the embodiment shown In Figure 5, the return force or biasing force tending to hold the magnet away from metal being tested is provided by a spring 228 which acts between the spigot 234 on the end of the arm 214 and a fixed anchor point 250.

The embodiment shown In Figure 6 differs from that shown in Figure 1 in that the arm 314 is si idably mounted within an elongate gulde 352.

In Figure 7, the magnet 412 Is directly mounted on a pivotally mounted contact arm 422 at an Intermediate part thereof, one end of which arm Is pivotally mounted on a rod 424 and is biased in a clockwise direction by a spring 428 and the other end of which is arranged to move from an abutment 454 to a contact 432 when metal Is sensed.

Figure 8 is similar to the embodiment descrlbed In Figure 7 with the exceptlon that the abutment 554 is provided on a si idably mounted adjustment member 556.

When the adJustment member Is slid towards the contact 532, the magnet 512 Is moved closer to a body belng tested and thus, if the Inclination of the tester Is not altered, less metal, or metal at a greater distance will cause the arm to pivot and connect with the contact 532.

Alternatively, when the member 556 Is slid in the opposite directlonHthe magnet Is moved away from the body belng tested and a greater amount or a closer proximity of metal Is required to cause pivotal movement of the lever.

In Figure 9 the adJustment member 656 is comprised by a rotatable wheel mounted on an offset axis 658. When the wheel Is pivoted, the spring of the magnet on the arm from a body being tested is altered.

In both of the embodiments described in Figures 8 and 9 the adJustment of the spacing of the magnet is intended to compensate for the effect of gravity acting on the magnet and arm. Thus If the weight of the magnet and arm were tending to act to cause the arm to pivot In an anti-clockwise direction the adjustment can be made to move the magnet away from a body being tested, in dependence upon the moment of that force about the pivot of the arm. Conversely, if the weight of the arm and magnet were acting to cause clockwise movement, the adjuster Is moved to decrease the distance between the magnet and a body being tested.

Accordingly, use of the adjustment member can enable the device to give consistent readings on the metallic qualIty of a body regardless of whether that surface Is facing upwardly, outward! or downwardly.

In either of the embodiments shown In Flgures 8 or 9 instead of, or In addition to the relative position of the magnet being adjusted when no magnetic force is exerted on the magnet, the relative position of the magnet to a body being tested when a magnetic force Is present may also be adjustable. This may be achieved by alterlng the positlon of the contacts 532 or 632 by suitable means, such as a silding member 556 or pivotal member similar to those shown In Figures 8 and 9.

Alternatlvely the position of the portion of the tester arranged to abut the vehicle may be altered such as by moving the axis of the wheel 16 relative to the tester.

Wlth this arrangement, when the magnet Is being biased towards a body by the magnetic force exerted between the magnet and vehicle, compensation can be made for the effects of gravity to enable the contact to be broken when the magnetic force drops below a predetermined amount, regardless of the direction in which the surface of the body faces.

In Figure 10, the magnet 712 is mounted on one side of a contact arm 722, the other side of which arm Is biased away from a body to be tested by a spring 728.

The magnet is able to move towards a body being tested through a housing 760, when metal Is detected, to enable contacts 727 on projecting ends of the arm 722 to connect with contacts 732.

The arm 822 shown in Figure 11 carries the magnet 812 towards its free end, one end of the arm 822 being pivotally mounted and the other end being biased In a clockwise directlon by a sprlng 828. When metal is sensed, the arm pivots in an anti-clockwlse direction to break the connectlon between the arm 822 and a make/break button or contact 832 to allow an indicatlon that there Is sufficient metal in the body being tested to be given.

It wil I be appreclated that each of the embodiments shown in Flgures 5 to 11 may be provided with appropriate circuitry to enable an Indication to be given when a body Is tested which has sufficient metal to enable the magnet to be attracted enough to cause the magnet to move.

Varlous modiflcations can be made to the testers described above. For instance, a pocket clip can be fitted. Alternatively or additionally, an Illuminating light may be included, possibly in the region of the wheel 16 of the device, in order that areas of the vehicle body can be Inspected in more detail. A further modification may be the inclusion of a tyre depth gauge.

Each of the embodiments shown in Figures 5 to 11 may be provided with a wheel as described in relation to Figure 1.

In any of the herein described embodiments, a light may be arranged to be Illuminated when the magnet is pulled towards metal in a vehicle, and the light may be arranged to go off when the magnetic force Is no longer sufficient to hold the magnet. Thus the tester will not consume power when it is not In use.

Claims

CLAIMS.

1. A body tester Including a magnet and Indlcating means arranged to provide an indication of a magnetic force, if any, exerted on the magnet.

2. A tester as claimed in Claim 1 in which the magnetic force Is arranged to be derived from metal In the body adjacent to the tester.

3. A tester as claimed in Claim 1 or Claim 2 In which an Indication is arranged to be given when a magnetic force exerted on the magnet exceeds a predetermined amount.

4. A tester as claimed in any preceding claim in which the Indication means provides an indlcation from a power source of the tester.

5. A tester as claimed in Claim 4 In which power Is only consumed from the power source when an indlcatlon of a magnetic force is belng given.

6. A tester as claimed in any preceding claim in which the magnet is movably mounted on the tester.

7. A tester as claimed in Claim 6 in which the magnet is slidably mounted on the tester.

8. A tester as claimed in Claim 6 in which the magnet is pivotally mounted on the tester.

9. A tester as claimed In any of Claims 6 to 8 In which the movement of the magnet is used in providing an indication of the magnetic force.

10. A tester as claimed in any preceding claim in which the magnet is biased in one direction of movement, and the magnetic force exerted on the magnet is arranged to -overcome that blas when metal In a body adJacent the tester Is sufficiently close to the surface of the body.

11. A tester as claimed In any preceding clalm which Is arranged to abut a body when testing that body.

12. A tester as claimed in Claim 11 including a rotatable portion arranged to ride over the surface of a body being tested.

13. A tester as claimed in Claim 11 or Claim 12 in which the magnetic force, If any, exerted between any metal In a body belng tested and the magnet assists in holding the tester against a body.

14. A tester as claimed in any preceding claim including adjustment means arranged to adjust the indication of a magnetic force.

15. A tester as claimed in Claim 14 in which the adJustment means includes means enabling the position of the magnet on the tester, when no magnetic force Is exerted on the magnet, to be altered.

16. A tester as claimed in Claim 14 or 15 In which the adjustment means Includes means enablIng the position of the magnet on the tester, when a magnetic force is exerted on the magnet, to be altered.

17. A tester as claimed in Claim 15 or 16 In which the adJustment means includes a slideably mounted member.

18. A tester as claimed in Claim 15 or Claim 16 in which the adJustment means Includes a pivotally mounted member.

19. A tester substantially as hereln described with reference to, and as shown in any of the accompanying figures.

20. A method of testing the metal in a body comprising locating a body tester including a magnet adjacent to the body, and Indicating when the magnetic force exerted on the magnet falls below a predetermined amount.

21. A method as claimed in Claim 20 comprising holding the tester in contact with the body.

22. A method as claimed In Claim 20 or Claim 21 comprising moving the tester over the body.

23. A method as claimed in Claim 20, 21 or 22 comprising maintaining the predetermined amount of magnetic force required to cause an Indication to be given substantially constant, regardless of the direction in which the surface of the body being tested faces.

24. A method as claimed in any of Clalms 20 to 23 comprising altering the relative positlon of the magnet to a body being tested when the force exerted on the magnet is below a predetermined amount.

25. A method as claimed in any of Clalms 20 to 24 comprising altering the positlon of a magnet on a tester when the force exerted on the magnet exceeds the predetermined amount.

26. A method of testing the metal in the body substantlally as hereln descrlbed with reference to, and as shown in any of the accompanying drawings.