Sheet tightening device, particularly for repairing car bodies, or the like

Abstract

 A sheet tightening/straightening device particularly for repairing car bodies or the like according to the invention comprises a clamp (1, 2) for straightening out dented, bent or damaged sheet metal. The clamp (1, 2) has a wedge locking system (12) which allows the application of a clamping force proportional to the pulling or pushing force.

Description

[0001] This invention concerns mechanics, in particular the technical sector of body-work equipment manufacturing, specifically referred to the manufacturing of devices for repairing bodies, damaged by crashes or bent in whatever way, and should preferably be used with hydraulic pumps.

[0002] At present, specific instruments to repair bodies by straightening out sheet metal, bent by crashes or damaged in whatever way, are not available on the market since this kind of repair is made manually using tools like hammers etc. and with the operator exerting pressure against the bent part to try to re-straighten the sheet metal. Unfortunately, this operation is time-consuming and difficult, as the outcome of manual work varies depending on the operator's skill, and usually requires much experience to obtain effective results. As specific instruments for straightening out damaged or bent sheet metal are not currently available on the market, this operation is very complex, expensive and of a doubtful outcome because only an experienced and skilled operator can do this repair work with satisfactory results.

[0003] This invention effectively solves the above problem, enabling anybody to straighten out damaged sheet metal quickly and easily and does not require any particular skill.

[0004] The intervention solves the problem by means of a sheet metal tightening/straightening device composed of a clamp for straightening out dented, bent or damaged sheet metal. The clamp is equipped with wedging parts on the half-clamps or cheeks against the sheet metal, which can be dynamically coupled with a pushing or pulling actuator, so that a clamping force can be applied proportional to the pushing or pulling force.

[0005] Thanks to this expedient, the repair work, i.e. straightening out dented, bent or somehow damaged sheet metal, can be done with the aid of straightening actuators, guaranteeing the repeatability of the repaired form, which it is possible to obtain.

[0006] The invention provides further characteristics whic are subject of the sub-claims.

[0007] The features of the invention and the advantages resulting there from are described better in the following description of a non limiting preferred embodiment illustrated in the enclosed drawings in which:

[0008] Figure 1 shows a view in direction of the clamoping axis of the two half-clamps, of a first embodiment of the straightening clamp.

[0009] Figure 2 shows a sectional view of the straightening clam, according to a plane parallel to the clamping axis of the two half-clamps.

[0010] Figure 3 shows a view of the clamp, according to the previous figures, and in a direction of sight perpendicular to the clamping axis.

[0011] Figure 4 shows a cross section transversally to the clamping axis of a modified embodiment of the sheet metal straightening clamp according to the previous figures.

[0012] Figure 5 shows a view in the direction of the clamping axis of a sheet metal straightening clamp according to Fig. 4.

[0013] Figure 6 shows the sheet metal straightening clamp according to Figs. 4 and 5, seen perpendicular to the clamping axis.

[0014] Figures 7 to 9 show several views of a cheek, i.e. one half of the clamp, according to the previous figures.

[0015] According to this invention, the sheet metal straightening clamp comprises two cheeks or half-clamps 1, 2 of a basically identical manufacture, one of them shown in Figs. 7 to 9. Each half-clamp 1, 2 is 'C'-shaped and there are two holes in the middle of the C, one of them is slotted 3 and extends towards the two peripheral branches of the 'C'; the pulling pin 6 is fitted and slides in this slot 3. The second hole 4, not slotted, houses a locking bolt 5. Each half-clamp has a knurled, toothed, or similar, gripping edge 7 at the top of one transverse branch of the 'C'-shaped part. The gripping edges 7 are used to grip the sheet metal above and below, where the clamp is to be fastened.

[0016] At the opposite end of the knurled gripping edge, projecting beyond the top of the other transverse branch of the 'C', each half-clamp has a plug 8 and a hole 9 respectively, used as a mutual reference to couple the two half-clamps 1 and 2. The half-clamp branch upper side inner edge is bevelled at 45°, thus forming a sloping surface 10 to engage a central double wedge. This wedge, inserted between the two half-clamps, fastens the clamp to the metal sheet with a force proportional to the force applied to the bevels 10 by the double wedge.

[0017] The locking bolt 5 passes through the holes 4 of the two half-clamps 1, 2 and on this bolt 5 a spring 11 can be inserted between the half-clamps 1, 2. The locking wedge, especially the double locking wedge 12, is made of steel and moved by a pushing or pulling pin 6. The pushing or pulling pin 6 passes through the slots 3 of the two half-clamps 1, 2 and can slide transversally, that is perpendicular to the extension of the bevels 10 of the half-clamps 1, 2.

[0018] The invention (see Figs. 1 to 6) makes it possible to use the clamp with at least two different configurations, operating the clamp by pulling at a right angle or parallel to the gripping direction respectively, i.e. in the direction of engagement of the double wedge 12.

[0019] Figures 1 to 3 show the sheet metal straightening clamp in a configuration where the pushing or pulling forces are applied parallel to the direction of engagement of the wedge 12 between the two half-clamps 1, 2. One end of the pulling pin 6 is equipped with couplings 15 to a pulling actuator (not shown), for example to the rod of a hydraulic jack. The couplings 15, shown on Figs. 1 to 3, consist of an adapter sleeve, the axis of which is parallel to the direction of engagement of the wedge 12; the adapter sleeve houses the rod of the hydraulic jack with its axis parallel to the sleeve axis.

[0020] The sheet straightening clamp is positioned to grip the metal sheet when the locking bolt 5 is fastened. Force is then applied to the adapter sleeve 15 by means of a jack connected to the sheet metal straightening clamp; the force is directed towards the engagement of the wedge 12 between the two half-clamps 1 and 2. This pushing force is transferred to the double-cone wedge 12 which acts on the two 45° bevels 10 at the end of the two half-clamps 1, 2, thus generating a clamping force proportional to the pushing force. The pushing force can obviously be replaced by an appropriately directed pulling force.

[0021] The second configuration, see Figs. 4 to 6, does not require an adapter sleeve. Another adapting or transmitting wedge 16 is used instead of the sleeve, and is inserted between the locking bolt 5 and the pulling pin 6 or the double-cone wedge 12 on the same side, opposite the 45° bevels 10 of the half-clamps 1, 2.

[0022] Advantageously as shown in Figure 4 the adapting wedge consists of a slider with a forked end where the locking bolt 5 is engaged, whereas the fork's prong between the above locking bolt and the pulling pin 6, i.e. the front side of the double-cone wedge 12, is bevelled to an adapting or transmitting wedge 16 shape. The slider's opposite end is equipped with devices to engage an actuator, in particular, the rod of a hydraulic jack or similar. The slider moves transversely with respect to the sliding direction of the pulling pin 6 and the double-cone wedge 12; the adapting or transmitting wedge acts on the double-cone wedge 12, generating, like the previous configuration, a clamping force proportional to the pulling force applied.

[0023] In both configurations illustrated, the pushing or pulling force is applied by coupling (keying) the pulling jack with the adapter sleeve 15 or the adapting or transmitting wedge 16.

[0024] Figures 1 to 3 show a horizontal section, a front view and profile of the clamp, respectively, on a scale of 1:2. The above figures also show the locking bolt 5 passing through the two half-clamps or cheeks 1, 2, with the spring 11 inserted between them. The figures also show the double-cone locking wedge 12 fixed on the pulling pin 6, and the adapter sleeve 15 to couple the pulling devices (not shown), which forms an integral part with the same pulling pin 6.

[0025] Figures 4 to 6 show a horizontal section, a front view and profile, respectively, of the first operating configuration on a scale of 1:2. These figures also show the locking bolt 5, the double-cone locking wedge 12 on the pulling pin 6 and the adapting or transmitting wedge 16 which acts on the double-cone wedge 12 when inserted between the latter and the locking bolt 5 transversally, i.e. perpendicular to the sliding movement of the double-cone wedge 12.

[0026] Figures 7 to 9 show a horizontal section, a front view and profile, respectively, of one half-clamp or cheek 1, 2) on a full size scale. The figures also show the half-clamp's 1, 2 'C' shaped part, the knurled edge 7 for gripping the sheet metal, the slotted hole 4 for sliding the pulling pin 6, together with the double-cone wedge 12 and the hole 3 to pass through the locking bolt 5. The holes, the cooperating centering and mutual reference plugs 8, 9 on the two half-clamps 1, 2 and the 45° bevelled surface 10 on the inner edge of the 'C'-shaped part's transversal branch are also shown.

[0027] The device concerned has been described and represented in an executive form simply for the sake of illustration and without any limitations to show its essential characteristics. It may therefore undergo many variations depending on industrial and commercial requirements, and may also use other systems and means, without losing its purpose.

[0028] Consequently, the application for a patent right must be understood to include every equivalent application of these concepts and every equivalent product manufactured and/or operating on the basis of any of the characteristics given in the claims hereafter.

Claims

1. Sheet tightening/straightening device particularly for repairing car bodies or the like, characterised by the fact that it is composed of a clamp (1, 2) for straightening out dented, bent or damaged sheet metal; the clamp (1, 2) has a wedge locking system (12) which allows the application of a clamping force proportional to the pulling or pushing force.

2. Device according to claim 1, characterised by the fact that it is composed of two coupled half-clamps (1, 2), each having two opposite sloping or bevelled surfaces (10) facing one another, and a locking wedge (12), in particular, a double wedge, acting on them.

3. Device according to claims 1 or 2, characterised by the fact that each half-clamp (1, 2) has two opposite knurled or toothed edges or surfaces, or similar, to anchor at the sheet metal.

4. Device according to one or several of the above claims, characterised by the fact that each of the two half-clamps (1, 2) has a slotted hole (3) with a pulling pin (6) passing through it and a double-cone locking wedge (12) fitted or fixed on it.

5. Device according to one or several of the above claims, characterised by the fact that the double-cone wedge (12) may be any shape, round, oval etc.

6. Device according to one or several of the above claims, characterised by the fact that a locking bolt (5) holds the two half-clamps (1, 2) together and supports a spring inserted between the two half-clamps (1, 2).

7. Sheet tightening/straightening device particularly for repairing car bodies or the like, characterised by all the features claimed and described above and those shown in the tables enclosed.

Drawing