Technical Field

The present invention relates to a bead-breaking unit and a method to provide a tyre-changing machine with a bead-breaking arm.

Background Art

Tyre-changing machines are commonly used for fitting/removing tyres of vehicle wheels on/from respective rims.

As is known, before being able to completely remove a tyre, it is necessary to detach the beads thereof from the seat of the respective rim.

To do this, a bead-breaking arm is used mounted on the tyre-changing machine itself.

In practice, the known tyre-changing machines include a bead-breaking unit comprising a bead-breaking arm arranged horizontally and having a first extremity hinged to a side of the body or base of the machine itself, outside of it.

The arm has a second extremity having a bead-breaking tool, also called "blade".

The arm is operated by a pneumatic or hydraulic cylinder which is also associated with the side of the base on which the bead-breaking arm is hinged, but on the side inside the body.

On said side of the body, the base has a protruding portion provided with an abutment surface that cooperates with the blade to carry out the bead breaking. This known solution has several drawbacks.

First of all, the maintenance or replacement of components of the bead-breaking unit is extremely inconvenient and expensive.

In fact, the base of the machine is obtained by welding the various parts, including the side on which the bead-breaking arm is mounted; to access the inside of the body, therefore, the maintenance operator is forced to remove a panel of the base and enter crouched under the machine, bringing with him/her the necessary tools.

The same problem arises during the assembly of the machine in the factory, when the assembly stages will occur as follows: fitting of the bead-breaking arm on the outside of the body;

fitting of the pneumatic or hydraulic cylinder inside the body;

kinematic connection of the pneumatic or hydraulic cylinder to the bead- breaking arm, through the side of the base.

Even in this case, the operator in charge of the assembly operations has to crouch within the base or pass through an opening at the bottom.

Description of the Invention

The main aim of the present invention is to devise a bead-breaking unit and a method to provide a tyre-changing machine with a bead-breaking arm which allow a more effective assembly and maintenance.

Another object of the present invention is to devise a bead-breaking unit and a method to provide a tyre-changing machine with a bead-breaking arm which allow to overcome the mentioned drawbacks of the prior art within the ambit of a simple, rational, easy and effective to use as well as affordable solution.

The above mentioned objects are achieved by the present bead-breaking unit, made in accordance with claim 1, and by the present method to provide a tyre- changing machine with a bead-breaking arm, made in accordance with claim 13.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become better evident from the description of several preferred, but not exclusive, embodiments of a bead-breaking unit of a method to provide a tyre-changing machine with a bead-breaking arm, illustrated by way of an indicative, but not limitative, example in the accompanying drawings in which:

Figure 1 is an axonometric view of a tyre-changing machine on which is mounted the bead-breaking unit according to the invention;

Figure 2 is the view of the previous illustration, with the bead-breaking unit disassembled;

Figure 3 is an axonometric view of the bead-breaking unit according to the invention;

Figure 4 is an exploded view of the bead-breaking unit according to the invention. Embodiments of the Invention

With particular reference to these illustrations, globally indicated by reference numeral 1 is a bead-breaking unit which can be mounted on a tyre-changing machine 2.

The unit 1 of the invention can be used for the first detachment of the tyre bead from the respective rim, prior to the operation of removing the tyre itself on the machine 2.

In detail, the machine 2 can be of the type comprising a gripping and rotation unit 3 of the rim and an upper arm 4 having a tool to fit/remove a tyre from a rim, as a result of its preliminary bead breaking.

The proposed bead-breaking unit 1 is specially intended to be arranged in correspondence of the base 5 of the machine 2, according to particular methods, as detailed below.

The unit 1 comprises a supporting frame 6 and at least a bead-breaking arm 7 having a first extremity hinged to the frame 6 and a second extremity opposite to the first one having a bead-breaking tool 8 suitable for breaking the bead of the tyre, e.g. a so-called bead-breaking "blade".

In detail, the arm 7 is arranged horizontally and is rotatable around a substantially vertical hinge axis.

The unit 1 of the invention also comprises operation means 9 for the movement of the arm 7, which are also mounted on the frame 6, e.g. comprising a pneumatic or hydraulic actuator.

Preferably, the frame 6 comprises an external side facing the arm 7 and an internal side opposite to the external one.

The frame 6 also comprises at least an opening 10 crossed with sliding freedom by the rod 11 of the actuator 9, a distal extremity of which being connected to the arm 7.

The barrel 12 or cylinder of the actuator 9 is arranged in use in the internal half- space defined by the frame 6, which internal half-space includes the mentioned internal side.

The external side may have at least a contrasting surface 21 against which in use the wheel with the tyre to bead break is positioned. The contrasting surface 21 is suitable for cooperating with the bead-breaking tool 8 to break the bead of the tyre.

This contrasting surface 21 is knurled so as to increase the friction coefficient with the wheel placed in abutment thereof.

Once the unit 1 has been mounted on the machine 2, the contrasting surface 21 is substantially vertical and the wheel rests on it vertically.

In practice, the arm 7 is suitable for oscillating, upon operation of the actuator 9, between a position of disengagement, wherein the blade 8 is more spaced away from the contrasting surface 21, and a position of intervention, wherein the blade 8 is closer to this surface 21 and is suitable for engaging on one side of the tyre of a wheel to bead break.

According to an important aspect of the invention, the unit 1 comprises fitting means 22 to fit in a removable way the frame 6 on the tyre-changing machine 2. To be precise, the unit 1 of the invention is suitable for being alternately mounted and removed as a whole on/from the base 5 of the machine 2.

Even more in detail, the frame 6 can be integrated in the base 5 of the machine 2, following its mounting, preferably going to define one of the walls of the base 5 (see Figures 1 and 2).

In practice, before mounting the unit 1 on the machine 2, the base 5 of the latter has an opening 13, as shown in figure 1.

The frame 6 has a shape and size such as to close such opening 13 and defines a wall of the base 5.

After assembly, the internal side remains inside the base 5, as well as the cylinder 12 of the actuator 9, while the external side and the arm 7 are arranged outside of the base 5 itself.

Preferably, the fitting means are made of a plurality of bolts 22 which can be coupled to special holes 14, 24 provided on the perimeter of the frame 6 and of the opening of base 5.

Preferably, the frame 6 comprises at least a protruding portion 15, 16 coming from said external side, having said contrasting surface 21.

Such protruding portion 15, 16 may be substantially perpendicular or substantially parallel to the arm 7. Preferably, the invention has two of these protruding portions 15, 16, one parallel and one perpendicular to the arm 7, arranged to form a T or a cross. The unit 1 can also include a contrasting plate 17 having a knurled external side 21 which defines the contrasting surface.

In this case, the plate 17 is fixed to the protruding element or elements 15, 16. If they are arranged in a T, then the plate 17 will have a T-shape.

The above mentioned proximal extremity of the arm 7 is preferably hinged to the protruding portion 15 parallel to the arm 7 itself, i.e. the one which in use is arranged horizontally.

The same protruding portion 15 may include the aforesaid opening 10 for the sliding of rod 11 of the actuator.

The protruding portions may be formed by metal profiled elements 15, 16 welded together and to a covering common plate 18 to define the frame 6 of the invention, said common plate 18 being useful to cover the parts of the wall of base 5 not occupied by the profiled elements 15, 16.

Furthermore, the common plate 18 is the component of frame 6 on which holes 24 are formed for bolts 22.

The common plate 18 comprises its own passage 19 facing the opening 10 above so as not to hinder rod 11 when crossing the actuator 9.

Before explaining the operation of the present technical solution, it is described the method of the invention devised to provide the tyre-changing machine 2 with the bead-breaking arm 7.

The method first of all comprises the stages to make available: a tyre-changing machine 2; a supporting frame 6; a bead-breaking arm 7 having a first free extremity and a second opposite extremity with a bead-breaking tool 8; operation means 9 for the movement of the arm 7; and fitting means 22 to mount in a removable way the frame 6 onto the machine 2.

The machine 2 and the different components of the bead-breaking unit 1 made available by the method of the invention are configured as those described above.

The free extremity of the arm 7 is hinged to the frame 6 and, subsequently, the operation means 9 are mounted on the frame 6, connecting them to the arm 7 so that they can control its rotation around the hinge.

At this point, the bead-breaking unit 1 is mounted, as a whole, onto the tyre- changing machine 2 by means of the fitting means 22.

In practice, the bead-breaking unit 1 of the invention is assembled separately from the tyre-changing machine 2 which is intended for.

Therefore, during the manufacturing process, the operator in charge of the mounting can assemble the unit 1 with great convenience and speed, without the need of having to work crouched at the base 5 of machine 2.

Similarly, when the operator in charge of maintenance has to repair or replace one component of the bead-breaking unit 1, he/she will simply have to remove the whole unit 1 from the base 5, by loosening the bolts 22, and perform his/her ob without having to take uncomfortable positions in which he/she is hampered and slowed down.

Furthermore, the invention offers the possibility of having, based on customers' specific needs, sets of different bead-breaking units, which can be mounted on different tyre-changing machines.

In fact, the different mechanical workshops may have special needs depending on the vehicles on which they usually work and depending on the cost they wish to pay for purchasing a tyre-changing machine 2.

In practice, the same machine 2 can be associated with different bead-breaking units 1 having arms 7 of different lengths and operation means 9 of different sizing.

In fact, provided that the holes 24 of frame 6 of all models of the bead-breaking unit 1 are always at the same mutual distance, which is that between the holes 14 of base 5, it is possible to combine at will the bead-breaking units 1 and the tyre-changing machines 2.

To this purpose, also to minimize manufacturing costs, all machines 2 which mount the units 1 according to the invention will be equipped with the same model of base 5.

It should also be noticed that the different sets of bead-breaking units 1 may differ by the sizing of arm 7 and actuator 9, but always have the same frame 6. These aspects also allow to manage inventory and logistics more efficiently. The possibility of combining different bead-breaking units with machines having different tools or optional items allows to offer a product which is targeted to the customer's needs as much as possible, unlike what occurs by employing the prior art.