[0001] The present invention relates to an improved tool for fixing drive pin blind rivets
in general, and in particular for wall fixing- metal blocks which are deformable upon
the application of a tension to an associated tension-fracturable drive pin.
[0002] It is known that rivets are particularly advantageous for connecting together sheet
metal and the like. It is also known that when one side of the workpieces to be joined
is not accessible, various types of rivets, known as "blind rivets" can be used, the
upsetting of which can be effected by operating through the rivet hole itself.
[0003] In such cases the fixing of the rivet is obtained by expansion of its shank, which
is usually caused by applying a tension to a drive pin used to introduce the rivet
into the hole in the parts to be connected. Such tension can be applied to such an
extent that the drive pin is fractured thereby, and blind rivets having fracturable
drive pins are commonly called "pop" rivets.
[0004] Such working procedures have suggested the possibility of employing blind or hollow
rivets in place of conventional expansion blocks (and the more recent pin- firing
guns) for fixing structures and objects of various types onto solid walls. In fact,
by introducing a rivet of the type described into a hole previously formed in a wall,
and exercising a traction on the drive pin inserted into it, leading substantially
to fracture of this drive pin, the expansion of the rivet shank-which takes place
is sufficient to ensure a secure anchorage to the wall itself. Such rivets are consequently
practically comparable from a functional point of view to expansion blocks.
[0005] It is likewise known that there are currently commercially available particular tools
which are able to exercise on the drive pin of a blind rivet the required tension
for the expansion of its shank. Such tools, however, are difficult to manoeuvre in
that they do not offer suitable holding points which can ensure a secure grip on the
tool itself during use.
[0006] The purpose of the present invention is to eliminate this above-mentioned disadvantage,
providing an improved tool for the fixing of drive pin blind rivets in general and,
in particular for the wall fixing of metal blocks by tension fracture, which will
be formed in such a way as to allow the user to hold the tool conveniently in any
circumstances.
[0007] Another particular object of the present invention is to provide an improved tool
for fixing drive pin blind rivets or the like in particular, fixing expandable metal
blocks by means of a tension fractured drive pin, which will be simple, easy and safe
to use.
[0008] Another object of the present invention is to provide an improved tool for fixing
drive pin blind rivets in general and, in particular for wall mounting metal blocks
using a tension fractured drive pin which is able to allow correct and gradual tension
to be applied to the drive pin in the metal block constituting the rivet or the like.
[0009] According to the present invention, an improved tool for fixing drive pin blind rivets
in general and, in particular, for fixing metal blocks to a wall using a tension-fractured
drive pin, is characterised by the fact that it comprises essentially a tubular body
mounted on a prismatic block coaxially and slidably within which is positioned a cylindrical
body carrying a pincer jaw; the sliding of this cylindrical body being effected by
a pair of bell crank levers pivoted to the tubular body and the lever ends of which
are pivoted to a pantograph structure provided with an operating handle, a gripping
handle being fixed to the said prismatic block, preferably in a non-movable manner.
[0010] Further objects and advantages of the improved tool for fixing pop rivets in general
and wall mounting metal blocks by tearing, which constitutes the subject of the present
invention, will become understood with the aid of the following description of a typical
embodiment of the tool itself, illustrated purely by way of example in the various
figures of the attached drawings, in which:
Figure 1 is a side view of the operating head of the tool;
Figure 2 is a view of the same tool showing it in position about to introduce a rivet
into a hole previously formed in the parts to be anchored; and
Figure 3 illustrates the same tool during the operation of applying tension to the
drive pin inserted within the hollow rivet.
[0011] With particular reference to the identifying numerals in the various figures of the
attached drawings, the improved tool for fixing drive pin blind rivets in general
and, in particular for fixing metal blocks by means of a tension fracturable drive
pin, comprises an operating head 1 constituted by a tubular body 2 having a suitably
shaped end portion 3 and mounted on a prismatic block 4 in which there is formed an
axial through hole.
[0012] Within this tubular body there is formed a cylindrical body
5 carrying, at one end, pincer jaws 6 and provided at its opposite end with an element
7 having a circumferential groove 8.
[0013] In the said prismatic block 4 there are formed slits in opposite positions, in which
there are fitted a pair of bell crank levers 9 pivoted at points 10 to the prismatic
block itself.
[0014] The force-applying arms 11 of these levers are introduced into the said circumferential
groove of the element 7, whilst the operating arms 12 of these levers are pivoted
to a pantograph structure 13 mounted on a robust handle 14.
[0015] In particular, on the said prismatic block 4 there is fitted, preferably in a non-movable
manner, a handle 15 which can be securely gripped by the operator for the purpose
of maintaining the head 1 perpendicular to the-wall during the block fixing operation.
[0016] In practice, with the pantograph structure 13 completely elongated as shown in Figure
2, the hollow rivet or block is fitted into and fully pressed home within the hole
formed in the wall 16, with the jaw 6 of the pincer being fitted over the drive pin
17. Subsequently, by firmly holding the head 1 with the handle 15 and pressing on
the pantograph structure by means of the handle 14 a progressive rotation of the levers
9 about the pivots 10 is caused. This rotation (Figure 3) is accompanied by a clamping
of the jaws 6 onto the drive pin 17 and a subsequent tension on the drive pin itself
sufficient to cause an adequate expansion of the rivet able to lock this latter into
the hole previously formed in the wall.
[0017] From what has been explained above and from observation of the various Figures of
the attached drawings, the great functionality and practicality in use which characterises
the improved tool of the invention will become apparent.
1. An improved tool for fixing drive pin blind rivets in general and, in particular,
for fixing metal blocks to a wall by applying tension to an associated drive pin (
17 ) , characterised by the fact that it comprises, essentially, a tubular housing
(2) mounted on a prismatic block (4) coaxially and slidably within which is positioned
a cylindrical body (5) carrying a pincer jaw (6), sliding of this cylindrical body
(5) being effected by a pair of bell crank levers (9) pivoted in the tubular body
. and the operating ends (12) of which are pivoted to a pantograph structure (13)
provided with an operating handle (14), a gripping handle (15) being fixed to the
said prismatic block (4) preferably in a non-movable manner.
2. A tool according to Claim 1, characterised by the fact that the said tubular housing
(2), constituting together with the cylindrical body (5), an operating head, has a
suitably shaped end portion (3) and is mounted on a prismatic block (4) in which there
is formed an axial through hole.
3. A tool according to Claim 1 or Claim 2, characterised by the fact that the said
cylindrical body (5) carries the pincer jaw (16) at one end and is provided at the
opposite end with an element (7) having a circumferential groove (8).
4. A tool according to any preceding Claim, characterised by the fact that the said
prismatic block (4) is formed with opposed slits within which the said bell crank
levers (9) are pivoted to the prismatic block (4) itself; one arm (11) of each such
bell crank lever (9) projecting into the said circumferential groove (8) of the said
element (7), whilst the other arms of each lever (9) is pivoted to the pantograph
structure (13).
5. A tool according to any preceding Claim, characterised by the fact that the said
prismatic block (4) is fitted in a non movable manner with a handle (15) which can
be gripped firmly by the operator during the use of the tool.