WO2012131486A1

WO2012131486A1 - Mechanical comparing device for body shops

Info

Publication number: WO2012131486A1
Application number: PCT/IB2012/000654
Authority: WO
Inventors: Arrigo ZUCCHI
Original assignee: Zucchi Arrigo
Priority date: 2011-03-31
Filing date: 2012-03-30
Publication date: 2012-10-04
Also published as: ITMI20110523A1

Abstract

The portable mechanical comparing device (100) is suitable for being mounted onto a damaged vehicle (V) for checking parts of bodywork of a first side of the vehicle (V) with respect to corresponding parts of the second side of the vehicle (V), and comprises a fastening group (110) to the vehicle (V), a reference structure (130) and a comparing group (150); in the reference structure (130) a reference axis (AR) is defined; the comparing group (150) is such as to allow detecting the position with respect to the reference axis (AR) of a point on the first side of the vehicle (V) and comparing it with the position of a corresponding point on the second side of the vehicle (V). The fastening group (110) comprises two main arms (111) of equal length, with respective first ends (112) hinged to the reference structure (130) according to first pivot axes (A1) in symmetrical positions with respect to the reference axis (AR), and second ends (113) provided with fastening means (114, 115) to the vehicle (V) at safe points thereof, symmetrical with respect to a longitudinal axis (AV) of the vehicle (V), so that the reference axis (AR) is at the longitudinal axis (AV) of the vehicle (V). The fastening group (110), with the two equal main arms (111), facilitates the correct positioning of the device (100) on the vehicle (V), so that the reference structure (130) is definitely in an axial position with respect to the vehicle (V).

Description

MECHANICAL COMPARING DEVICE FOR BODY SHOPS

DESCRIPTION

The present invention refers to a mechanical comparing device for body shops, for checking parts of bodywork of one side of a vehicle with respect to corresponding parts of the other side of the vehicle, which can aid in the reconstruction of parts of bodywork of a damaged vehicle.

In a body shop, parts of the bodywork of a vehicle that have been damaged in an accident are reconstructed. By the terms "reconstruct" and "reconstruction" reference is made to every operation that leads to the restoration of the original shape and dimensions of a part of damaged bodywork; the reconstruction can include the total or partial replacement of the piece, its deformation, and both of these, according to the type of damage suffered.

In the great variety of accidents that a vehicle can suffer, there are many accidents that damage only one side of the vehicle. In these cases, the body shop worker can reconstruct the part on the damaged side by using as a mirror model the corresponding part on the non-damaged side. In this operation, the body shop worker can advantageously use mechanical comparing or measuring devices, like those described, for example, in US 5343628 A, US 5647139 A, EP 0922927 A2. The same devices are also used for precisely verifying the amount of area damaged by the accident, before moving on to the reconstruction; it is indeed possible for small deformations to not be perceived by the naked eye, even if it is normally necessary to precisely reconstruct all the parts deformed in this way so as to not jeopardise the operation and safety of the vehicle.

These known comparing devices are certainly useful, but are not without drawbacks. In particular, their constructive complexity sometimes makes them both costly and difficult to use; especially, the difficulty of use causes the body shop worker to make mistakes. In order to reduce the possibility of errors, optical laser devices have been developed and are currently used. These devices ensure very high precision, however they are very costly and therefore their use is limited to large body shops. The problem at the basis of the present invention is that of devising a mechanical device that is particularly simple and easy to use, and that ensures optimal precision without having a prohibitive cost for a small body shop.

Therefore, in its most general terms the present invention concerns a device according to claim 1 ; preferred characteristics are shown in the dependent claims.

More in particular, the invention concerns a portable mechanical comparing device for body shops, suitable for being mounted onto a damaged vehicle for checking parts of bodywork of a first side of the vehicle with respect to corresponding parts of the second side of the vehicle, comprising a fastening group to the vehicle, a reference structure carried by the fastening group and a comparing group carried by the reference structure, in which:

in the reference structure a reference axis is defined;

the comparing group is such as to allow detecting the position with respect to the reference axis of a point on the first side of the vehicle and comparing it with the position of a corresponding point on the second side of the vehicle;

characterised in that:

the fastening group comprises two main arms of equal length, each having:

respective first ends hinged to the reference structure according to first pivot axes in symmetrical positions with respect to the reference axis, second ends opposite to the first ends,

in which each second end of the main arms of the fastening group is provided with fastening means suitable for being fastened to the vehicle at definite points thereof, symmetrical with respect to a longitudinal axis of the vehicle,

in which through said fastening means the comparing device can be mounted onto the vehicle, with the reference axis at the longitudinal axis of the vehicle.

This device does not require fixed installation and is extremely simple and therefore has a low cost, also affordable to very small body shops; moreover, its simplicity makes its use simple and therefore minimises mistakes. In particular, the fastening group, with the two main arms having equal length, makes the correct positioning of the device on the vehicle extremely simple and definite, so that the reference structure is definitely in an axial position with respect to the vehicle. It is obvious that the correct positioning of the reference structure is the condition by which the device makes it possible to exactly detect the positions on the two sides of the vehicle.

Preferably, the fastening group comprises two auxiliary arms, hinged at a first end thereof to the reference structure according to second pivot axes symmetrical with respect to the reference axis and each hinged at its own second end opposite the first to a respective one of the main arms according to two respective third pivot axes, in which the first, second and third pivot axes are parallel to one another and in which the distance between each third pivot axis and the first pivot axis is equal to the distance between each third pivot axis and the second pivot axis.

There is thus an articulated parallelogram structure, which gives a much greater solidity to the fastening group. The greater solidity in fact excludes possible accidental deformations, thus allowing a more simple and precise use to be obtained.

Preferably, the fastening means comprise a hollow sleeve formed at the second end of each of the main arms and a threaded nut, for insertion and respectively screwing onto corresponding threaded pins provided on the vehicle. These pins can be, for example, in the case of most auto-vehicles, the pins to which the hinges of the hood (front or rear, according to the damaged area) are fixed; these pins, arranged near to the uprights of the passenger compartment, are in areas which are statistically rarely affected by deformations of a normal accident. In some cases, according to the type of fastening of the hood, the bodywork of the vehicle can provide threaded holes instead of pins; in such a case, double threaded columns can be used, inserted on one side in the hollow sleeve of the bodywork, on the other in the hollow sleeve of the main arm of the comparing device.

The reference structure can have different configurations. In a particularly simplified embodiment, the reference structure comprises the single pin (real or even virtual) between the two main arms; by virtual pin it is meant that the two arms are configured so as to be hinged to one another according to the first axis, without there being an actual pin between them. In this case, the comparing group is clearly taken by the group of the two main arms, at the first pivot axis.

Preferably, the reference structure comprises a master shaft arranged according to the reference axis, a first sleeve able to slide on the master shaft along the reference axis, on which first sleeve the two main arms of the fastening group are hinged according to the first pivot axes, and a first block for blocking the master shaft in the first sleeve. Provision of the master shaft makes it possible to have a mechanical element that extends along the axis of the vehicle; this master shaft can thus be used to support the comparing group, or also several comparing groups, in the axial position.

Preferably, the reference structure comprises a second sleeve, aligned with the first sleeve and able to slide on the master shaft along the reference axis, on which second sleeve the two auxiliary arms of the fastening group are hinged according to the second pivot axes. This configuration gives greater solidity and undeformability to the device, ensuring that the master shaft is and remains in the axial position.

The first pivot axes of the two main arms can coincide (therefore also at the reference axis) or distinct from one another (therefore spaced from the reference axis), just like the second pivot axes of the two auxiliary arms. In the case in which the first pivot axes coincide, there is the advantage of having greater constructive simplicity. In the case in which, on the other hand, they are distinct from one another, the distance from the reference axis allows the device to be folded away better, with a very small bulk; this is an important advantage, especially for small body shops in which it is important for the device to not take up too much space when it is not being used.

In a preferred embodiment, the fastening group comprises a further second sleeve, aligned with the first sleeve and with the second sleeve and is able to slide on the master shaft, and two further auxiliary arms, hinged at a first end thereof to the further second sleeve according to further second pivot axes symmetrical with respect to the reference axis, and hinged at its own second end opposite the first to a respective one of the main arms according to two respective further third pivot axes. The presence of two pairs of auxiliary arms improves the solidity of the device, thus making it even more precise.

In the aforementioned embodiment, it is preferable for the first pivot axes of the two main arms to be distinct from one another, just like the second pivot axes and the further second pivot axes. Indeed, the presence of two pairs of auxiliary arms allows the possibility of folding up the arms of the device easily when it is not being used, limiting the bulk.

Preferably, each auxiliary arm and/or each possible further auxiliary arm has a curved shape. Even this characteristic promotes the reduction of the bulk when the device is folded up; with a suitable shape of the auxiliary arms, it is possible to ensure that in the folded position these arms are arranged perfectly alongside the master shaft.

Preferably, the comparing group comprises a rotatable arm hinged to the reference structure, an adjustable stop rotation system suitable for determining extreme right and left positions rotated by the same angle on opposite sides with respect to the reference axis, and a check tip at one end of the rotatable arm. An arm of this kind makes it possible to be used in a very simple and intuitive manner, and therefore facilitates the precision of work of the body shop worker.

In a preferred variant, the rotatable arm is hinged to the reference structure at the reference axis.

In a preferred variant, the comparing group comprises a -first mobile support that is slidably mounted on the master shaft, a second block for blocking the first mobile support on the master shaft, a rotatable arm hinged to the first mobile support according to a fourth pivot axis, an adjustable stop rotation system suitable for determining extreme right and left positions rotated by the same angle on opposite sides with respect to the reference axis, and a check tip at one end of the rotatable arm remote from the fourth pivot axis. In such a way the simplicity and intuition of operation is combined to the solidity of the support provided by the master shaft. Preferably, the adjustable stop rotation system comprises a second mobile support slidably mounted on the master shaft, a third block for blocking the second mobile support on the master shaft, and a pair of abutments on the second mobile support, symmetrically arranged with respect to the reference axis. The symmetrical arrangement of the abutments on the second mobile support ensures in a simple and effective manner the corresponding symmetry of the positioning of the rotatable arm towards both sides of the vehicle.

Preferably, the rotatable arm can provide adjustments, so as to better adapt to different vehicles and to different damage on them. For example, the rotatable arm can have adjustable length, or the check tip on the rotatable arm can have an adjustable position.

In a variant of the invention, the comparing group comprises: a third and a fourth sleeve, slidably mounted on the master shaft, a fourth block for blocking the master shaft in the third or in the fourth sleeve,

two comparing arms of equal length, each having:

respective first ends hinged to the third sleeve according to fifth pivot axes symmetrical with respect to the reference axis,

second ends opposite the first, provided with a check tip, two auxiliary comparing arms, hinged to one another and to the fourth sleeve at a first end according to the sixth pivot axis symmetrical with respect to the reference axis and each hinged at its own second end opposite the first to a respective one of the comparing arms according to two respective seventh pivot axes, in which the fifth, sixth and seventh pivot axes are parallel to one another and in which the distance between each sixth pivot axis and the fifth pivot axis is equal to the distance between each seventh pivot axis and the fifth pivot axis.

According to this more complex variant, the comparing group is shaped in a substantially analogous way as the fastening group in its most complete version, i.e. with an articulated parallelogram structure. In this variant, the comparison thus occurs directly, without having to move a rotatable arm on one side and on the other side of the vehicle. This variant can be preferred -for example- to verify rapidly a series of many reference points: by bringing the check tip of one of the two comparing arms successively on the points of the non damaged side, the check tip of the other arm makes it possible to verify, one after the other, the correctness of the points on the reconstructed/damaged side. Moreover, this variant is useful also when repairing a damaged vehicle on both sides; indeed, it is possible to detect the measurements on an identical non damaged vehicle, block the configuration of the comparing device by means of mentioned blocks, transfer on the damaged vehicle the comparing device (or even just its comparing group, if on the damaged vehicle an identical fastening group with the reference structure has already been mounted), and then continue verifying the desired points of the bodywork.

The master shaft can have a polygonal section (typically square- shaped) or circular. A polygonal section makes it possible to exclude the rotation of the various sleeves mounted on it, thus promoting the solidity of the device. Moreover, a circular section makes it possible to use the possibility of rotation around the master shaft, for example in the comparing group.

In a preferred embodiment, the master shaft has a circular section and the comparing group comprises an arm mounted on the master shaft that is able to rotate around it and able to slide along it, an end stop plate of the arm, mounted on the master shaft able to rotate around it and able to slide along it, and a block for blocking the end stop plate on the master shaft. In such a way, the use of the comparing group is very simple and safe; in particular, in the case in which the configuration of the vehicle allows it, the end stop plate can advantageously rest on the bodywork of the vehicle, thus allowing a greater stability of the position of the master shaft.

Further characteristics and advantages of a device according to the invention shall become clearer from the following description of some preferred embodiments, given with reference to the attached drawings. In such drawings:

fig. 1 is a perspective view of part of a mechanical comparing device for body shops according to the invention, with a fastening group and a reference structure before the application of the device to a vehicle;

fig. 2 is a front view of the part of device of fig. 1 , applied to the vehicle;

fig. 3 is a perspective view of a complete device according to an embodiment of the invention, in the step of being applied to a vehicle, with the rotatable arm of the comparing group facing towards the left side of the vehicle;

fig. 4 is a perspective view of the device of fig. 3, with the comparing group arranged so as to detect the position of a point on the left side of the vehicle;

fig. 5 is a view in enlarged scale of some details of the device of figs.

3 and 4;

fig. 6 is a perspective view of the device of fig. 3, with the comparing group arranged so as to verify the position of the corresponding point on the right side of the vehicle;

fig. 7 is a perspective view of a device according to a second embodiment of the invention, before the device is applied to a vehicle;

figs. 8 and 9 are plan views from above of the device of fig. 7 mounted onto the vehicle, with the rotatable arm facing on two sides of the vehicle;

fig. 10 is a perspective view of a device according to a third embodiment of the invention, applied to a vehicle;

figs, from 11 to 14 are perspective views of a device according to a fourth embodiment of the invention, applied to a vehicle and with the comparing group in different operation positions;

fig. 15 is a view of the device of figs. 11-14, in their folded condition when not in use, with the comparing group separated from the rest of the device.

In the figures, reference numeral 100 wholly indicates a mechanical comparing device for body shops according to a first embodiment of the invention, schematically shown in figures 1 to 6 together with a vehicle V. It should be noted that the vehicle V is represented in a schematic manner, without highlighting of the damaged parts or rather after it has been repaired; the vehicle V has a longitudinal axis of symmetry AV.

The device 100 essentially comprises three parts: a fastening group 110 to the vehicle V, a reference structure 130 carried by the fastening group 110, and a comparing group 150 carried by the reference structure 130; in the reference structure 130 a reference axis AR is defined, which in use coincides with the axis of the vehicle AV.

The fastening group 110 comprises two main arms 111 , of equal length, hinged to one another and to the reference structure 130 at a first pivot axis A1. Each main arm 11 has a first end 112 at the first pivot axis A1 and a second end 113 provided with a hollow sleeve 114. The hollow sleeve 114 is intended to be inserted on a threaded stem SF provided on the vehicle V for mounting a hood (not represented in the figures); a threaded nut 115 is provided for screw engaging with the threaded stem SF and thus blocking in position the end 113 of the main arm 111. The hollow sleeve 114 and the threaded nut 115 form fastening means for fastening the fastening group 110 to definite points of the vehicle V, by this meaning points whose correct position is certain, on both sides of the vehicle V.

The comparing device 100 is shown engaged on the front part of the vehicle V, above it, but it can be clearly engaged on different parts of the vehicle V, using the most suitable definite points according to the cases .

In the case in which the vehicle V does not provide threaded stems at definite points but threaded holes (like in the cases illustrated in the figures), in such holes threaded columns SF are inserted, so as to allow, in any case, the fastening of the fastening group 110 in the same way.

The fastening group 110 also comprises two auxiliary arms 121 , hinged to one another at a second pivot axis A2. Each auxiliary arm 121 has a first end 122 at the second pivot axis A2 and a second end 123 hinged to a respective main arm 111 according to a third pivot axis A3. The first, second and third pivot axes, A1 , A2 and A3, are parallel to one another, and the distance between each third pivot axis A3 and the first pivot axis A1 is equal to the distance between the same third pivot axis A3 and the second pivot axis A2, so as to form an articulated parallelogram structure.

The reference structure 130 comprises a first sleeve 131 , on which are hinged the two main arms 111 of the fastening group 110 according to the first pivot axis A1 , and a second sleeve 132, aligned with the first sleeve 131 , on which are hinged the two auxiliary arms 121 of the fastening group 110 according to the second pivot axis A2. The reference structure 130 also comprises a master shaft 133, extending according to the reference axis AR and slidingly inserted in the first and in the second sleeve 131 and 132, and a first block 134, for blocking the master shaft 133 in the first sleeve 131 ; the first block 134 (just like the other blocks that shall be mentioned in the rest of the description) is preferably a screw, provided with a butterfly-shaped head for an easy manual actuation.

The comparing group 150 comprises a first support 151 , able to be moved guided on the master shaft 133 and able to be blocked on it by means of a second block 152. A single rotatable arm 153 is hinged to the first support 151 of the comparing group 150 according to a fourth pivot axis A4, parallel to the first, second and third pivot axes A1 , A2 and A3. The rotatable arm 153 is provided with a check tip 154 at its end remote from the fourth pivot axis A4.

The comparing group 150 comprises a second support 155, able to be moved guided on the master shaft 133 and able to be blocked on it by means of a third block 156. On the second support 155 two abutments 157 are provided for the rotatable arm 153, symmetrically arranged with respect to the master shaft 133 and therefore with respect to the longitudinal axis AV of the vehicle V; the abutments 157 act as an end stop for the rotation of the rotatable arm 153.

The rotatable arm 153 can be advantageously adjusted: it can be adjusted in length, by varying its position of hinging to the first support 151 by means of a further block 158, or by varying the position of the check tip 154 by means of a second further block 159.

In use, the comparing device 100 is first mounted with its fastening group 110 on the vehicle V, fastening it by screwing the nuts 115 (figs. 1 and 2). With its mounting, the position of the master shaft 133 is established, naturally being arranged with the reference axis AR along the longitudinal axis AV of the vehicle V, since the points SF are symmetrically arranged and the main arms 111 have equal length. The first and second supports 151 and 155 are also symmetrical along the axis AV.

Subsequently, the position of the first support 151 and the adjustments on the rotatable arm 153 are determined, so that the check tip 154 is exactly on the point of the bodywork of the vehicle V of which the position is desired to be checked. The position of the first support 151 and the adjustments of the rotatable arm 153 are thus blocked, acting on the second block 152 and on the further blocks 158 and 159. See figs. 3 and 5.

At this point, the second support 155 is brought up to the first support 151 , so that one of the two abutments 157 rests against the rotatable arm 153; once this position has been reached, also the second support is blocked, by acting on the third block 156. See fig. 4.

The device 100 is now ready to allow comparing between corresponding points of the vehicle V on its two sides. It is sufficient for such a purpose to rotate the rotatable arm 153 on the two sides, to the end stops established by the symmetrical abutments 157.

It is thus possible -for example- to verify in a simple manner the position of points of an area that has been reconstructed during repair that involves only one side of the vehicle V, comparing them with corresponding points on the other (intact) side of the same vehicle V. In the same way, it is - possible to verify, before repairs, the correspondence of points of the two sides of a vehicle which has been in an accident, so as to highlight small deformations which are not easily visible with the naked eye.

A simplified variant of the invention is shown in figures 7, 8 and 9. In such figures, a comparing device 200 is shown having a simplified fastening group 210, reference structure 230 and comparing group 250.

The fastening group 210 comprises only two main arms 211 , hinged at their first ends 212 at a first pivot axis B1 and provided with tubes 214 perforated at the second ends 213, as well as threaded nuts 215 for fastening to the threaded stems SF of the vehicle. Auxiliary arms are not provided.

The reference structure 230 comprises only one pin 235 at the first pivot axis B1 ; a reference axis BR, which does not correspond here to any shaft is defined, but only at an ideal line which divides the angle formed by the two main arms 211 in equal parts.

The comparing group 250 comprises a single support 251 hinged to the pin 235 and a rotatable arm 253, carried by the support 251 and able to rotate with it around the first pivot axis B1. The rotatable arm 253 is provided with a check tip 254 at its end which is remote from the first pivot axis B1. The comparing group 250 also comprises an adjustable support 255 which carries a bracket 257 able to rotate for hooking the rotatable arm 253 to the main arms 211 of the fastening group 210; the support 255 can slide on the rotatable arm 253 and can be blocked on it in the desired position by means of a block 256.

The rotatable arm 253 can be adjusted in length, by varying its position of hinging to the single support 251 by means of a further block 258 or by varying the position of the check tip 254 by means of a second further block 259.

In use, the comparing device 200 is mounted with its fastening group 210 on the vehicle V, as described for the fastening group 110 of the comparing device 100 (fig. 7). With its mounting, the position of the pin 235 is established, naturally being arranged along the longitudinal axis AV of the vehicle V, since the safe points are symmetrically arranged and the main arms 211 have equal length.

Subsequently, the adjustments on the rotatable arm 253 are determined, so that the check tip 254 is exactly on the point of the bodywork of the vehicle V of which the position is wished to be checked. The adjustments of the rotatable arm 253 are thus blocked, acting on the further blocks 258 and 259. See fig. 8.

The comparing device 200 is now immediately ready so as to allow comparing between corresponding points of the vehicle V on its two sides. It is sufficient for such a purpose to rotate the rotatable arm 253 on the two sides, to the end stops established by the bracket 257 against the main arms 211. See fig. 9. The comparing device 200 is thus faster to use than the comparing device 100; on the other hand, its slimmer structure makes it easily deformable and therefore potentially less accurate.

Another variant of the invention is shown in fig. 10. In such a figure, a comparing device 300 is shown having a fastening group 310, a reference structure 330 (with relative reference axis CR) and a comparing group 350.

The fastening group 310 and the reference structure 330 are respectively the same as the fastening group 110 and the reference structure 150 of the comparing device 100, and their elements are respectively the same (and therefore not described): main arms 3 1 , ends thereof 312 and 313, hollow sleeves 314, threaded nuts 315, auxiliary arms 321 , ends thereof 322 and 323, first and second sleeve 331 and 332, master shaft 333, first block 334, first, second and third pivot axes, C1 , C2 and C3.

The comparing group 350 comprises a third and a fourth sleeve 351 and 352, slidably mounted on the master shaft 333, a fourth block 353 for blocking the master shaft 333 in the third sleeve 351 and/or in the fourth sleeve 352, and two comparing arms 363 of equal length; the two comparing arms 363 each have a respective first end 364, that is hinged to the third sleeve 351 according to a fifth pivot axis C5 that is common to the two comparing arms 363, and a second end 365 opposite the first, provided with a check tip 366. The comparing group 350 also comprises two auxiliary comparing arms 367, that are hinged to one another and to the fourth sleeve 352 at a first end 368 according to a sixth pivot axis C6 and each hinged at its own second end 369 opposite the first to a respective one of the comparing arms 363 according to two respective seventh pivot axes C7; the fifth, sixth and seventh pivot axes C5, C6 and C7 are parallel to one another; the distance between each sixth pivot axis C6 and the fifth pivot axis C5 is equal to the distance between each seventh pivot axis C7 and the fifth pivot axis C5, so as to form an articulated parallelogram structure.

In use, the fastening to the vehicle V and therefore the arranging of the master shaft 333 occurs in the same way described for the comparing device 100, with the reference axis CR along the longitudinal axis AV of the vehicle V.

Once the master shaft 333 has been positioned, the comparing group 350 shaped like an articulated parallelogram is immediately available to compare positions of corresponding points on the two sides of the vehicle V.

It is thus possible to operate like for the comparing devices 100 and 200, so as to allow comparing between corresponding points of the vehicle V on its two sides. Moreover, with the comparing device 300 it is possible to detect the correct position of points on a reference vehicle, for example the same as a vehicle that has been in an accident V that is however intact, block the configuration of the comparing device 300 by means of the blocks 353, transfer on the damaged vehicle V the comparing device 300 (or also only its comparing group 350, if on the damaged vehicle V an identical fastening group 310 has already been fastened with the reference structure 330), and then proceed to verifying the desired points of the bodywork.

The comparing device 300 is thus is of more rapid and complete use than the comparing device 100; on the other hand, its heavier and more complex structure makes it more inconvenient to use.

Yet another variant of the invention is shown in figs. 11-15. In such figures, a comparing device 400 is shown having a fastening group 410, a reference structure 430 (with relative reference axis DR) and a comparing group 450.

The fastening group 410 comprises two main arms 411 , of equal length, hinged to one another and to the reference structure 430 at respective first pivot axes D1. Each main arm 411 has a first end 412 at the first pivot axis D1 and a second end 413 provided with a seat 416 with block 417 for a tip 4 8; additional seats 416' for the tip 418 are provided spaced from the end 413, to be used on narrow vehicles. The tip 418 is thus fastened in an adjustable manner to the arm 411. In use, the tip 418 is intended to be inserted in a fixed point made up of a hole on the vehicle V (not highlighted in the figures), for example a hole for housing a bolt for fastening a motor hood, that has been suitably removed. The fastening group 410 also comprises two auxiliary arms 421 , which are hinged to the reference structure 430 at second pivot axes D2, spaced and symmetrical with respect to the reference axis DR. Each auxiliary arm 421 has a first end 422 at the second pivot axis D2 and a second end 423 hinged to a respective main arm 411 according to a third pivot axis D3. Moreover, the fastening group 410 comprises two further auxiliary arms 421', hinged to the reference structure 430 at further second pivot axes D2', spaced and symmetrical with respect to the reference axis DR. Each further auxiliary arm 421' has a first end 422' at the further second pivot axis D2' and a second end 423' hinged to a respective main arm 411 according to a further third pivot axis D3'. All mentioned first pivot axes D1 , D2, D2', D3 and D3', are parallel to one another.

The reference structure 430 comprises a first sleeve 431 , on which the two main arms 411 of the fastening group 410 are hinged according to the first pivot axes D1 , a second sleeve 432, aligned with the first sleeve 431 , on which the two auxiliary arms 421 of the fastening group 410 are hinged according to the second pivot axes D2, and a further second sleeve 432', aligned with the first and with the second sleeve 431 and 432, on which the two further auxiliary arms 421' of the fastening group 410 are hinged according to the further second pivot axes D2'. The reference structure 430 also comprises a master shaft 433, having a circular cross-section, extending according to the reference axis DR and slidably inserted in the first, second and further second sleeve 431 , 432 and 432'. Blocks can be provided (not highlighted in the drawings) for blocking the master shaft 433 in the sleeves 431 , 432 and 432'.

The comparing group 450 comprises a rotatable arm 453, which is directly hinged on the master shaft 433 according to the reference axis DR. The arm 453 has a structure that can be lengthened telescopically and is provided with a check tip 454, which can be adjusted and rotated, at its end remote from the master shaft 433. The arm 453 can also slide along the master shaft 433. The arm 453 can be variously adjusted, analogously as the arms 153, 253 and 353.

The comparing group 450 also comprises an end-stop plate 463 of the arm 453, mounted on the master shaft 433 in a position near to the arm 453; the plate 463 is mounted able to slide and rotate on the master shaft 433 and is provided with a block 464 for blocking on the master shaft 433. The plate 463 is provided with two seats 471 in which two feet 472 are slidably inserted; respective blocks 473 make it possible to block the feet 472 in position inside the seats 471.

In use, the comparing device 400 is firstly mounted with its fastening group 410 on the vehicle V, with the tips 418 inserted in respective holes in the vehicle, at safe points thereof. With its mounting, the position of the master shaft 433 is established, which is naturally arranged with the reference axis DR along the longitudinal axis AV of the vehicle V, since the points SF are symmetrically arranged and the main arms 411 have equal length.

Subsequently, the position of the plate 463 is determined on the master shaft 433. For such a purpose, the plate 463 is first made to slide along the shaft 433 until it reaches a position in which it can possibly rest on the bodywork of the vehicle V (through the feet 472), then it is visually aligned with the bodywork of the vehicle V (in particular towards the fastening points of the fastening group 410) so as to determine the correct angular position on the shaft 433. At the end, the plate 463 is blocked in the position found, just like the feet 472. It should be noted that this positioning - only apparently not vary accurate due to the operation having been carried out visually - in reality makes it possible to operate easily and accurately also in the case in which the vehicle is in the slightly inclined position, for example when the floor of the body shop is not horizontal.

Subsequently, the adjustments on the rotatable arm 453 are determined, so that the check tip 454 is exactly on the point of the bodywork of the vehicle V of which the position is desired to be checked, with the arm 453 resting at the end stop against the plate 463. The adjustments of the rotatable arm 453 are thus blocked, acting upon the suitable blocks.

The comparing device 400 is now ready to allow comparing between corresponding points of the vehicle V on its two sides. It is sufficient for such a purpose to rotate the rotatable arm 453 on the two sides, to the end stops established by the plate 463. See figures 11-14. It should in particular be noted that the tip 454 is rotated by 180° when the arm 453 passes from one side of the vehicle V to the other; see in particular figures 12 and 13.

The comparing device 400 is thus rapid to use like the comparing device 200, whilst ensuring a much greater solidity.

Moreover, when it is not being used, the comparing device 400 can be easily folded away completely (see fig. 15), thanks to the position of the first pivot axes spaced from the reference axis DR and thanks to the curved shape of the auxiliary arms 421 and 421'.

Of course, a man skilled in the art can easily carry out modifications to what has been described, without for this reason departing from the scope defined by the following claims. In particular, the mounting on a same master shaft of more than one comparing group can be provided, for example one like the group 150 and one like the group 350, just like it is possible to have any combination of locking groups and of comparing groups presented here.

Claims

1. Portable mechanical comparing device for body shops, suitable for being mounted onto a damaged vehicle (V) for checking parts of bodywork of a first side of the vehicle (V) with respect to corresponding parts of the second side of the vehicle (V), comprising a fastening group (110; 210; 310; 410) to the vehicle (V), a reference structure (130; 230; 330; 430) carried by the fastening group (1 10; 210; 310; 410) and a comparing group (150; 250; 350; 450) carried by the reference structure ( 30; 230; 330; 430), wherein:

in the reference structure (130; 230; 330; 430) a reference axis (AR; BR; CR; DR) is defined;

the comparing group (150; 250; 350; 450) is such as to allow detecting the position with respect to the reference axis (AR) of a point on the first side of the vehicle (V) and comparing it with the position of a corresponding point on the second side of the vehicle (V);

the fastening group (1 10; 210; 310; 410) comprises two main arms (1 1 1 ; 21 1 ; 31 1 ; 411) of equal length, having:

respective first ends (1 12; 212; 312; 412) hinged to the reference structure (130; 230; 330; 430) according to first pivot axes (A1 ; B1 ; C1 ; D1) in symmetrical positions with respect to the reference axis (AR; BR; CR; DR),

second ends (113; 213; 313; 413) opposite to the first ends, characterised in that

each second end (1 13; 213; 313; 413) of the main arms (1 1 1 ; 21 1 ; 31 1 ; 41 1) of the fastening group (1 10; 210; 310; 410) is provided with fastening means (114, 115; 214, 215; 314, 315; 418) suitable for fastening to the vehicle (V) at safe points thereof, symmetrical with respect to a longitudinal axis (AV) of the vehicle (V), wherein through said fastening means (114, 1 15; 214, 215; 314, 315; 418) the comparing device can be mounted onto the vehicle (V), with the reference axis (AR; BR; CR; DR) at the longitudinal axis (AV) of the vehicle (V).

2. Device according to claim 1 , wherein the fastening group (1 10; 310; 410) comprises two auxiliary arms (121 ; 321 ; 421), hinged at a first end thereof (122; 322; 422) to the reference structure according to second pivot axes (A2; C2; D2) symmetrical with respect to the reference axis (AR; CR; DR) and each hinged at its second end (123; 323; 423) opposite the first to a respective one of the main arms (111 ; 311 ; 411) according to two respective third pivot axes (A3; C3; D3), wherein the first, second and third pivot axes (A1 , A2, A3; C1 , C2, C3; D1 , D2, D3) are parallel to one another and wherein the distance between each third pivot axis (A3; C3; D3) and the first pivot axis (A ; C1 ; D1) is equal to the distance between each third pivot axis (A3; C3; D3) and the second pivot axis (A2; C2; D2).

3. Device according to claim 1 , wherein the fastening means comprise a hollow sleeve (114; 214; 314) at the second end (113; 213; 313) of each of the main arms (111 ; 211 ; 311 ) and a threaded nut (115; 215; 315), for insertion and respectively screwing onto corresponding threaded pins (SF) provided on the vehicle (V).

4. Device according to claim 1 , wherein the fastening means comprise a tip (418) at the second end (413) of each of the main arms (411), for insertion in corresponding holes provided on the vehicle (V).

5. Device according to claim 2, wherein the reference structure (130; 330; 430) comprises a master shaft (133; 333; 433) arranged according to the reference axis (AR; CR; DR), a first sleeve (131 ; 331 ; 431) able to slide on the master shaft along the reference axis-(AR; CR; DR), on which first sleeve (131 ; 331 ; 431) the two main arms (111 ; 311 ; 411) of the fastening group (110; 310; 410) are hinged according to the first pivot axes (A1 ; C1 ; D1), and a first block (134; 334; 434) for blocking the master shaft (133; 333; 433) into the first sleeve (131 ; 331 ; 431).

6. Device according to claim 5, wherein the reference structure (130; 330; 430) comprises a second sleeve (132; 332; 432), aligned with the first sleeve (131 ; 331 ; 431) and able to slide on the master shaft (133; 333; 433) along the reference axis (AR; CR; DR), on which second sleeve (132; 332; 432) the two auxiliary arms (121 ; 321 ; 421) of the fastening group (110; 310; 410) are hinged according to the second pivot axes (A2; C2; D2).

7. Device according to any of claims 2 to 6, wherein the first pivot axes (A1 ; C1) of the two main arms (111 ; 311) coincide, and wherein the second pivot axes (A2; C2) of the two auxiliary arms (121 ; 321) coincide.

8. Device according to claim 2, wherein the fastening group (410) comprises a further second sleeve (432'), aligned with the first sleeve (431) and with the second sleeve (432) and able to slide on the master shaft (433), and two further auxiliary arms (421'), hinged at a first end thereof (422) to the further second sleeve (432') according to further second pivot axes (D2') symmetrical with respect to the reference axis (DR), and hinged at its second end (423) opposite the first to a respective one of the main arms (411) according to two respective further third pivot axes (D3').

9. Device according to claim 8, wherein the first pivot axes (D1) of the two main arms (411) are distinct from one another, wherein the second pivot axes (D2) of the two auxiliary arms (421) are distinct from one another, and wherein the further second pivot axes (D2') of the two auxiliary arms (421') are distinct from one another.

10. Device according to any of claims 2 to 8, wherein each auxiliary arm (421) and/or each possible further auxiliary arm (421') has a curved shape.

11. Device according to claim 1 , wherein the comparing group (150; 250; 450) comprises a rotatable arm (153; 253; 453) hinged to the reference structure (130; 230; 430), an adjustable stop rotation system (155, 157; 255, 257; 463) suitable for determining extreme right and left positions rotated by the same angle on opposite sides with respect to the reference axis (AR; BR; DR), and a check tip (154; 254; 454) at one end of the rotatable arm (153; 253; 453).

12. Device according to claim 10, wherein the rotatable arm (253; 453) is hinged to the reference structure (230; 430) at the reference axis (AR; DR).

13. Device according to claim 5, wherein the comparing group (130) comprises a first mobile support (151) slidably mounted on the master shaft (133), a second block (152) for blocking the first mobile support (151) on the master shaft (133), a rotatable arm (153) hinged to the first mobile support (151) according to a fourth pivot axis (A4), an adjustable stop rotation system (155, 157) suitable for determining extreme right and left positions rotated by the same angle on opposite sides with respect to the reference axis (AR), and a check tip (154) at one end of the rotatable arm (153), remote from the fourth pivot axis (A4).

14. Device according to claim 13, wherein the adjustable stop rotation system comprises a second mobile support (155) slidably mounted on the master shaft (133), a third block 156) for blocking the second mobile support (155) on the master shaft (133), and a pair of abutments (157) on the second mobile support (155), symmetrically arranged with respect to the reference axis (AR).

15. Device according to claim 5, wherein the comparing group (350) comprises:

a third and a fourth sleeve (351 , 352), slidably mounted on the master shaft (333),

a fourth block (353) for blocking the master shaft (333) in the third or in the fourth sleeve (351 , 352),

two comparing arms (363) of equal length, each having:

respective first ends (364) hinged to the third sleeve (351) according to fifth pivot axes (C5) symmetrical with respect to the reference axis (AR),

second ends (365) opposite the first, provided with a check tip

(366),

two auxiliary comparing arms (367), hinged to the fourth sleeve (352) at a first end (368) according to sixth pivot axes (C6) symmetrical with respect to the reference axis (AR) and each hinged at its own second end (369) opposite the first to a respective one of the comparing arms (363) according to two respective seventh pivot axes (C7), wherein the fifth, sixth and seventh pivot axes (C5, C6, C7) are parallel to one another and wherein the distance between each sixth pivot axis (C6) and the fifth pivot axis (C5) is equal to the distance between each seventh pivot axis (C7) and the fifth pivot axis (C5).

16. Device according to claim 5, wherein the master shaft (433) has a circular section and wherein the comparing group (450) comprises an arm (453) mounted on the master shaft (433) able to rotate around it and able to slide along it, an end stop plate (463) of the arm (453), mounted on the master shaft (433) able to rotate around it and able to slide along it, and a block (464) for blocking the end stop plate (463) on the master shaft (433).