BACKGROUND OF THE INVENTION The present invention relates to a manual tool for fixing mechanical inserts, in particular for fixing rivet elements of male and female type.

More precisely, the manual tool is usable for fixing a rivet of collapsable type i.e. that can be axially deformable so as to cause the radial enlargement of an annular portion thereof that permanently constrains the rivet on the hosting seat.

STATE OF THE ART

The use is known of motor-driven tools for fixing metal rivets of collapsable type to metal sheets, plates or wood panels, and which exploit the power supplied by an electric drill or other electric or compressed-air machine tools. For example, riveting guns of pneumatic or hydraulic type are known, comprising a grip and a hydraulic cylinder to which a threaded gripping unit is connected that is arranged for coupling with a rivet to be deformed by a drawing or dragging action.

Unfortunately, in certain situations or applications, using the aforesaid machine tools can be uneconomical or difficult, both because of possible lack of electric power or compressed air and because of the inconvenience of conveying to places to be reached where "in situ" riveting tasks are required.

Other hand tools exist, such as riveting grippers that are drivable only by manual force. Nevertheless, also these hand tools have dimensions and weights that make the use thereof unsuitable or even impossible in certain situations, for example where the zones to which to fix the rivet are particularly narrow.

Further, these tools, in order to be able to adapt to different rivet dimensions, require certain parts to be replaced by those of the right size, and often this replacement task is not immediate and as easy to perform as would be desired. In addition, the cost of such tools is not always moderate, in fact may not be acceptable in cases in which it is intended to perform only few or sporadic riveting tasks.

It would be accordingly desirable to have available a tool of extremely small weight and dimensions that is thus easy to transport and store, cheap to make and very versatile in use. OBJECTS OF THE INVENTION

One object of the invention is to provide a hand riveting tool that is particularly simplified from the structural and functional point of view, that is thus very reliable and also extremely advantageous financially to make.

Another object is to provide a riveting tool of significantly modest dimensions and weight, such as to be easily transportable without any difficulty for an operator, and such as to make the use thereof particularly suitable and advantageous for fixing rivets in zones that are narrow and very difficult to reach.

Another object is to provide a hand riveting tool that is able to adapt very easily and rapidly to rivets of male or female type of different diameters.

These and other objects and advantages are obtainable by riveting tools as defined in the attached claims.

SHORT DESCRIPTION OF THE DRAWINGS

The features and advantages of the hand riveting tools according to the invention will become clearer from the following description, with reference to the drawings, in which:

Figures 1 and 2 are two perspective views of a first embodiment of a riveting tool according to the invention, with which a rivet to be fixed is coupled; Figure 3 is an exploded view of the assembly of Figures 1 and 2;

Figure 4 is a longitudinal view of the assembly of Figure 1 ;

Figure 5 is a frontal view of the riveting tool;

Figure 6 is a longitudinal section taken along the plane VI- VI in Figure 4;

Figure 7 shows schematically a fixing operation for fixing a rivet by the riveting tool according to the invention;

Figures 8 and 9 show two distinct operating steps of the riveting tool;

Figure 10 shows the result of the fixing operation for fixing a rivet of female type that is threaded internally and deformed in the collapsed fixing configuration;

Figure 11 is an exploded view of a second embodiment of a riveting tool for fixing a rivet of male type, provided with an externally threaded protrusion;

Figure 12 is a section that shows the second embodiment of a riveting tool with which a male rivet is temporarily associated that is inserted into a housing seat;

Figure 13 shows the male rivet at the end of the fixing operation, in which it is deformed into the collapsed fixing configuration in the housing seat.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the attached Figures, a hand riveting tool 101 is disclosed for fixing a mechanical insert 2 or 102 in a housing seat 3. The insert 2, 102, in particular, is a metal rivet of collapsable type, and the housing seat 3 can be a hole 3 or opening obtained on a plate 4 or metal sheet or wooden panel or another material etc.

With reference to Figures 1 to 10, a first embodiment of the riveting tool 1 is disclosed.

The riveting tool comprises a spacer element 5 provided with an axial passage opening 6 and having a contrasting end 7 that is suitable for coming to rest on, and contrasting, a front edge zone B of the rivet 2 of female type.

The spacer element 5 is of cylindrical shape and has an inner diameter dl that is less than the maximum outer diameter D2 of the rivet 2. This enables the spacer element 5 to come to rest correctly on the front edge zone B of the rivet 2 to be able to perform correctly its contrasting action against the rivet 2 whilst the latter is pulled by the pulling member 10.

The spacer element 5 has an outer diameter D3 that is greater than the maximum external diameter D2 of the rivet 2 by as much as is required and is anyway limited to contain as far as possible the transverse overall dimensions of the riveting tool 1. In particular, the outer diameter D3 satisfies the following relation:

D2< D3 <3*D2

that in tests has been found to lead to satisfactory results: the transverse dimension of the tool is hardly greater than the transverse dimension of the rivet 2, the riveting tool being thus slim and such as to reach easily the narrowest points of a surface to be riveted, showing at the same time great operating efficacy and reliability.

The simple cylindrical shape of the spacer element 5 contributes to simplifying further the structural configuration of the hand riveting tool 1, facilitating still further the making thereof and slashing manufacturing costs thereof.

The spacer element 5 is made of hardened steel, provided with great mechanical resistance and hardness. Nevertheless, the spacer element 5 can also be made of another material provided that it is suitable for performing the correct contrasting function for which it is intended.

At the contrasting end 7 of the spacer element 5, a resting and contrasting surface 15 is obtained that is knurled to prevent rotation of the mechanical insert 2 with respect to the housing seat 3.

The riveting tool comprises a thrust bearing unit 8 to support and transfer the axial loads, and arranged for resting on a second end 9 of the spacer element 5, and a pulling member 10 having a shape that is oblong.

The pulling member 10 in particular can be configured simply as a common screw, making the tool 1 very easy to make. The pulling member 10 extends along a longitudinal axis A and is intended to be inserted through the thrust bearing unit 8 and through at least part of the axial passage opening 6 of the spacer element 5 for coupling through screwing with the rivet 2.

The hand riveting tool 1 lastly comprises a simple threaded nut 11 that is screwable on the pulling member 10 and arranged for coming to rest on the thrust bearing unit 8 on an opposite side to the spacer element 5. The thrust bearing unit 8 consists of two annular elements 16 made of high resistance steel, between which rolling elements 17 are interposed that enable the axial load to be transferred between the nut element 11 and the spacer element 5, facilitating the mutual rotation in the absence of friction. The pulling member or screw 10 is provided with a shaped head 12 that is suitable for engaging a key C I, whereas the nut element 11 is engageable by a second key C2 to be rotated in relation to the pulling member 10. The head 12 can be shaped to couple with a wrench, or have a shaped recess in which to insert another clamping tool.

The pulling member 10 comprises a shank 13 provided externally with a threaded surface S I suitable for engaging a corresponding threaded surface S2 of the nut element 11. The thrust bearing unit 8 and the nut element 11 have external diameters that are not greater than the outer diameter D3 of the spacer element 5. In particular, the thrust bearing unit 8 has a diameter that is substantially equal to the outer diameter D3.

Owing to the aforesaid configuration, advantageously the transverse dimensions and the weight of the riveting tool 1 are maintained at maximum to confer on the latter particular ease of handling, versatility and ease of use.

With reference to Figures 11 to 13, a second embodiment of a riveting tool is shown that is indicated in general by the number 101, which is particularly suitable for fixing a rivet 102 of male type, i.e. provided with a protrusion P having external threading S5 on which a nut or in general a threaded fixing element can be screwed. Parts that are common or equivalent to what has been disclosed previously are indicated by the same reference number or are increased by 100.

The solution of Figures 11 to 13 has all the general features of the preceding embodiment of Figures 1 to 10 with the differences that are disclosed below.

The riveting tool 101 comprises a pulling member 110, such as a screw with a head, which unlike the preceding embodiment is provided with a tapped portion 114, provided at an end of the shank 113 opposite the shaped head 112. The tapped portion 114 comprises a cavity 114 that extends axially inside the shank 113 and is provided with inner threading S4 that is shaped for being able to be coupled by screwing with the threaded protrusion P of a male rivet 102.

It is possible to provide a kit comprising a plurality of riveting tools 1 and/or tools that are sized to operate on different rivet diameters 2 and/or 102. A plurality of pulling members 10 and/or of 110 of differing diameter can thus be used, just like a plurality of spacer elements and nut elements and thrust bearing units of various diameters to adapt to different geometries and diameters of the rivets.

The operation of the riveting tool 1 with reference to Figures 7 to 10 is disclosed below.

Once the nut element 11 is threaded onto the screw 10 and once the thrust bearing unit 8 and the spacer element 5 are inserted on the shank of the aforesaid screw 10, the screw 10 is reciprocally tightened with the female rivet 2. Accordingly, the threaded surface S 1 engages the inner threaded surface S3 of the rivet 2.

The rivet 2, whilst it is coupled with the riveting tool, is introduced into the housing seat 3 provided for example on the slab 4 on which fixing occurs. At this point, as shown in Figures 7 and 8, by a first key C I engaging the head 12 of the screw 10, and a second key C2 engaging the nut element 11, the operation of deforming the rivet can occur that leads the latter to be fixed in the respective seat 3.

By the first key CI, rotation of the key 10 is prevented, whereas with the second key C2 the nut element 11 is rotated according to an unscrewing rotation direction R with respect to the aforesaid screw 10. This operation imposes on the screw 10 an axial movement T in the extraction direction with respect to the housing seat 3. This is possible owing to the opposite contrasting action on the nut element 11 by the spacer element 5. Owing to the interposition of the thrust bearing unit 8, no friction is generated between the spacer element 5 and the nut element 11 and the latter can be rotated with respect to the screw 10 more easily, i.e. without having to overcome the contrasting actions due to mutual friction with the spacer element 5. The manual force for rotating the nut element 11 is thus exploited entirely to pull the screw 10, causing the deformation of the rivet 2. The knurled resting and contrasting surface 15 of the spacer element prevents rotation of the rivet 2.

The rotation of the nut element 11 and the pulling action exerted by the screw 10 continue until the rivet 2 is deformed into a collapsed configuration W that constrains the rivet 2 firmly on the housing seat 3.

As shown in figure 9, the rivet is stressed axially to be deformed so as to cause the radial enlargement of an annular portion thereof in addition to the diameter of the housing hole 3, thus fixing permanently the rivet to the housing plate or slab.

At this point, operating only with the first key C I, the screw 10 is unscrewed from the rivet 2, thus removing the entire riveting tool from the rivet 2, which remains fixed in the housing seat 3 as schematized in figure 10. In the case of the other embodiment, shown in Figures 11 to 13, the same identical procedure to that disclosed is followed. The only difference consists of the fact that the screw coupling between screw 110 and male rivet 102 occurs by inserting and tightening the threaded protrusion P of the rivet 102 inside the tapped cavity 114 of the screw 110. The result of the operation performed by the riveting tool 102 is visible in figure 13, which shows the male rivet 102 collapsed and fixed in the seat 3 of the plate or panel 4. From what has been disclosed and illustrated, it is clear that the riveting tool, 101 according to the invention successfully achieves the set objects explained above.

The essential configuration of the riveting tool consists of only four mechanical elements:

- a spacer element,

a thrust bearing,

a nut,

a screw. The great cheapness and reliability that such a structural simplification brings about is clear. The ease of adaptation to various rivet types and dimensions, whether of male or female type, makes the proposed riveting tool a highly versatile solution that is usable without difficulty, also by a user who is not very expert. Any element that is part of the riveting tool according to the invention can be replaced by other equivalents in structural and functional terms and the materials, insofar as they are compatible with the specific use for which they are intended, can be chosen appropriately according to requirements requested and according to the available prior art.

It is possible to configure and size the riveting tool according to specific needs and applications, with possible variations on and/or additions to what has been disclosed above and illustrated in the attached drawings without thereby leaving the claimed protective scope.