[0001] This specification relates to a demand for an utility model to a method for mechanical
riveting, whose evident object consists on allowing the definitive mechanical connection
and fixing of parts and pieces, namely hinges designed, for instance, for articulate
ladders in such a form that it dismisses the means known and used in the art till
present day.
[0002] Methods and/or processes for mechanical connection and/or fixing are well known,
namely through tightening screws undispensable for removable connexions but also by
means of several types of welding or riveting connections.
[0003] Generally known are the troubles linked with some processes as, for example, welding,
when it is to connect different materials as steel or iron and aluminium, or mechanical
tightening by screws, wich through use and innerent vibrations tend to require a periodical
inspection of respective tighteness, or also riveting, even with fast rivets, that
is time wasting and expensive to be executed.
[0004] Long since the art has been asking progressively more for working methods and processes
that along with a better global quality could present lesser production costs.
[0005] It is a main object of this utility model to conceive a process for mutual riveting
of parts and pieces consisting of different materials, and that simultaneously presents
an appropriate mechanical strength and low production costs.
[0006] Thus, the process described thereafter consists basically on foreseeing some reamed
drillings upon the part with stronger material (for example, iron or steel), hollow
or solid, and that is designed to be introduced into an hollow end of another part
made from a different and weaker material (for instance, aluminium), which will will
suffer from outside and exactly in the direction of each one of said reamed drillings
of the inner side, a pessure the forces the soft material of the outer side to warp
in and to enter into said reamed zones, thus fixing together respectively a part or
piece one another.
[0007] With the aid of the annexed figures that integrate this description without any limitative
character, refering only one of several possible forms of execution of the processe,
its innerent virtues shall stand out therefrom once that any and all the variants
of this process will fall under the scope of it, unresponsive to the method and type
of machinery used.
- Fig. 1 -
- Is an elevational side view of an hinge and a partial section AB;
- Fig. 2 -
- is an elevational side view of a type of hinged ladder, with the hinges refered in
Fig. 1, in compasses overture.
[0008] The hinge (1) used, for instance, in hinged ladders (Fig. 2) presents two terminal
arms (2), with specially reamed recesses or drillings (3) in number of four or more,
depending on the applications and loads at stake, mainly made of thougher material
(iron or steel), where each one of said terminals (2) of the hinge enter respective
aluminium tube ends (4) for exemple with a rectangular profile, in which at least
two of its opposed sides, and in the direction of each one of respective reamed recesses
or drillings (3) from the inner located part, are produced by means (punches) already
basically known some pressures that conduct to the mechanical deformation of the outer
part material unsresponsive to the method used therefor, forcing it to fit precisely
and closely into the rounded ream and in depth into respective special reamed recesses
or drillings (3) with the produced respective protrusions (5).
[0009] The reams (3), are specially executed with the shape of rounded edges in order to
avoid the weaker material being the target to shearing stress when subject to respective
mechanical deformation or protrusion (5).
[0010] Mechanical deformations (5) as well as special reams (3) are executed by specific
tool elements, obviously designed and conceived for this new riveting process, although
this elements are operated by known machines of manual, electrical, hydraulic or pneumatic
command.
[0011] This way connections resistant to traction and flexing as per international normative
claims are obtained, without resource to classical riveting, welding or mechanical
clipping, a novelty that leads necessarily to an economy in production.
1. Process for mechanical riveting, that consists in allowing a definitive mechanical
connection and fixing of parts and pieces made of differente materials as, for instance,
hinges (1) for hinged ladders dismissing the classical means hitherto known and used
in the art, characterized in that the parts under connexion (2 and 4) present respectively
the inner one (2), some specially reamed recesses or drillings (3) with rouded edges,
and the outer one (4), on at least two of its opposed sides, some respective mechanical
deformations or protrusions (5) in relation to each one of said recesses or drillings
(3), where they enter with a close fitting and precisely, to fix togheter one another
the parts (2 and 4).
