ITMO20120194A1 - DEMOLITION HAMMER WITH OPTIMIZED RESISTANCE. - Google Patents

Description

â € œOPTIMIZED RESISTANCE DEMOLITION HAMMERâ €.

DESCRIPTION

The present invention relates to a demolition hammer with optimized resistance.

There are known demolition hammers generally used for crushing rocks or the like or for drilling the road surface. These demolition hammers are fluid-powered machines and essentially consist of a body for containing valve means for distributing a fluid medium for feeding a linear actuator equipped with a piston driven by reciprocating motion along a direction of percussion and acting like a hammer on a tool (chisel) guided in alternating sliding inside a support. The actuator is usually interposed between the body and the support carrying the tool. The assembly of the demolition hammer takes place by connecting with tie rods engaged in the body and in the support to tighten them together.

Each tie rod consists of a screw, of suitable dimensions, inserted passing through the body and having the threaded root engaged in a corresponding blind and threaded seat obtained or brought back to the support. The head end of the screw can be shaped to define an abutment shoulder on the body or be also threaded (stud) and be coupled with a nut that is found on the body itself.

In any case, one or both ends of each tie rod are connected to the body and / or support of the tool by means of a threaded connection.

It should be considered that the tie rods are critical components of the demolition hammer, as they are subjected to strong stresses during use due to the working pressures and vibrations transmitted in the impact of the piston on the tool.

In case of breakage of one or more tie rods, however, the consequent misalignment of the distributor valve means, of the actuator and of the tool can cause seizure of the piston with considerable damage to the demolition hammer.

These known types of demolition hammers are not free from drawbacks including the fact in most cases the breakage of the tie rods occurs at the threaded ends, and in particular at the height of the first threads.

In order to obviate this drawback, threads with increased pitch and / or rounded ends have been created, which however do not allow to obtain a considerable increase in the reliability of the demolition hammers.

The aim of the present invention is to eliminate the aforementioned drawbacks of the known art by devising a demolition hammer with optimized resistance which allows to drastically reduce, if not eliminate, the cases of breakage of the tie rods, increasing their resistance to fatigue. In the context of this technical task, another object of the present invention is to optimize the reliability and duration of the demolition hammers over time, reducing maintenance costs and inefficiencies linked to the intervention times on the same for the replacement of damaged components.

Not least object of the present invention is that of being able to be incorporated both in demolition hammers of new production and in existing demolition hammers simply by replacing some components.

A further object of the present invention is to present a structure that is simple, relatively easy to implement in practice, safe in use and effective in operation, as well as having a relatively low cost.

This aim and these objects are all achieved by the present demolition hammer with optimized resistance comprising a body for containing valve means for distributing a fluid medium to a linear actuator equipped with a piston alternately movable along a direction of percussion and acting on a tool of demolition guided in alternating sliding by a support, the body and the support being arranged substantially aligned along the direction of impact with the actuator interposed between them, a plurality of tie rods connecting said body and said support being also provided, each of the which has a first end associated with said body and a second end associated with said support by means of respective connection units, characterized in that at least one of said connection units is of the obstacle type.

Further characteristics and advantages of the present invention will become more evident from the detailed description of some preferred, but not exclusive, embodiments of a demolition hammer with optimized resistance, illustrated by way of example, but not of limitation, in the accompanying drawings in which:

Figure 1 is a partially exploded schematic view in axonometry of a first embodiment of the demolition hammer according to the invention;

Figure 2 is a schematic axonometric view of the demolition hammer of Figure 1 in the assembled configuration;

figure 3 is a schematic side view of the demolition hammer of figure 2;

figure 4 is a partial sectional view according to the plane IV-IV of figure 3;

figure 5 is a schematic view in axonometry, partially exploded, of a second embodiment of the demolition hammer according to the invention;

figure 6 is a schematic axonometric view of the demolition hammer of figure 5 in the assembled configuration;

figure 7 is a schematic side view of the demolition hammer of figure 6;

figure 8 is a partial sectional view according to plan VIII-VIII of figure 7;

figure 9 is a schematic view in axonometry, partially exploded, of a third embodiment of the demolition hammer according to the invention;

figure 10 is a schematic axonometric view of the demolition hammer of figure 9 in the assembled configuration;

figure 11 is a schematic side view of the demolition hammer of figure 10;

figure 12 is a partial sectional view according to the XII-XII plane of figure 11;

figure 13 is a schematic view in axonometry, partially exploded, of a fourth embodiment of the demolition hammer according to the invention;

figure 14 is a schematic axonometric view of the demolition hammer of figure 13 in the assembled configuration;

figure 15 is a schematic side view of the demolition hammer of figure 14;

figure 16 is a partial sectional view according to the XVI-XVI plane of figure 15.

With particular reference to these figures, 1 generally indicates a demolition hammer with optimized resistance.

The demolition hammer 1 comprises a body 2 for containing valve means for distributing a fluid medium, for example hydraulic oil or air, to a linear actuator 3 equipped with an alternately movable piston and acting along a direction of percussion on a tool 5 of demolition guided in alternating sliding inside a support 4 along the direction of impact, which with reference to the figures extends vertically.

The aforementioned parts of the demolition hammer 1 are of the conventional type and therefore not described or represented in detail.

The demolition hammer 1 also provides for an accumulator fixed to the body 2, an outer covering and protection casing and a handle in correspondence with the body 2 for gripping by the user, not shown in the figures.

The body 2 and the support 4 are arranged aligned along the direction of impact, with the actuator 3 interposed between them.

The tool 5 can be of the type of a chisel extending along the direction of impact, but it is not excluded that the demolition hammer 1 can mount tools of different shapes. The demolition hammer 1 also comprises a plurality of tie rods 6 for connecting the body 2 and the support 4. Four tie rods 6 are generally provided, arranged at the vertices of the support 4, having a substantially quadrangular cross-section, but alternative shapes are not excluded. embodiments that provide for a different number or a different configuration of the tie rods 6, also on the basis of the geometry of the body 2 and of the support 4.

These tie rods 6 consist of rectilinear elements arranged parallel to the direction of impact and each of them has a first end 6a associated with the body 2 and a second end 6b, opposite to the previous one, associated with the support 4 by means of respective connection groups 7.

More in detail, each tie rod 6 is inserted through a corresponding through hole 11 defined on the body 2, with the first end 6a protruding from the body itself on the opposite side of that facing the actuator 3 and with the second end 6b inserted in a relative blind hole 12 obtained on the support 4.

The body 2 is equipped with an abutment surface 13, which surrounds the perimeter of the end of each through hole 11 open at the first end 6a of the relative tie rod 6. At least one of the connection groups 7 interposed between the ends 6a and 6b of each tie rod 6 and, respectively, the body 2 and the support 4 is of the type for obstacle 7 ', as an alternative to the traditional threaded connections.

Conveniently, the demolition hammer 1 provides for obstacle connection units 7 'interposed between the second end 6b of each tie rod 6 and the support 4, since it has been verified that this area is subjected to the greatest stresses.

The demolition hammer 1 can have obstacle connection units 7 'also interposed between the first end 6a of each tie rod 6 and the body 2.

Each obstacle connection unit 7 'consists of at least one preferably cylindrical pin 8, so-called pin or pin, arranged transversely to a relative tie rod 6 and engaged in a corresponding seat 9 associated with at least the tie rod itself.

Said seat 9 can have a recess 9a obtained laterally on the tie rod 6, in case the pin 8 is arranged partially protruding to the side with respect to it, or a through hole if the pin 8 completely crosses the section of the tie rod 6. To obtain a better stability of the connection, the seat 9 is preferably also associated with the body 2 or with the support 4 and comprises a housing 9b defined or placed on one of them. However, it is not excluded that the seat 9 is defined solely on the tie rod and that the pin 8 simply rests on the body 2 or on the support 4, without dedicated housings being provided on them.

According to the specific configuration of the body 2 or of the support 4, the housing 9b can be defined directly on one of them or be obtained on an annular element 10 fitted along the tie rod 6 until it abuts on the body 2 or on the support 4.

In order to obtain a greater resistance of the connection without weakening the tie rod 11, each obstacle connection group 7 'preferably provides two pins 8 arranged parallel to each other on opposite sides of the corresponding tie rod 6 and two corresponding seats 9, defined by respective recesses 9a made on the tie rod itself, as well as, possibly, by a housing 9b associated with the body 2 or the support 4.

In a first embodiment (Figures 1-4) the demolition hammer 1 provides for obstacle connection units 7 'at both ends 6a and 6b of each tie rod 6.

At the first ends 6a, each obstacle connection unit 7 'comprises an annular element 10 having a face adapted to abut the corresponding abutment surface 13 and bearing, on the opposite face, a pair of parallel grooves defining the housings 9b for the extremal portions of the pins 8.

At the second ends 6b, on the other hand, each obstacle connection unit 7 'comprises a pair of housings 9b defined by the side wings of a slot 14 suitably T-shaped defined on the support 4.

The assembly of the demolition hammer 1 foresees the insertion of each tie rod 6 through the corresponding through hole 11 until the second end 6b is found on the bottom of the relative blind hole 12, the positioning of the pins 8 through the slot 14 in correspondence with the second ends the same, the introduction of the annular element 10 along the tie rod 6 until it rests on the abutment surface 13, the traction of the tie rod 6 taken at the first end 6a protruding from the body 2 by means of a conventional pre-tensioning device, the positioning of the pins 8 resting on the housings 9b and the release of the tie rod 6 which, by contracting, brings the recesses 9a to abut on the pins themselves, tightening the connection.

In a second embodiment (Figures 5-8) the demolition hammer 1 provides for connection groups 7 by means of threaded elements at the first ends 6a and obstacle connection groups 7 'at the second ends 6b, completely similar to those described above.

Each connection group 7 has an external thread 15 obtained at the first end 6a of the relative tie rod 6 and a tightening nut 16 coupled to it and which is found on the abutment surface 13, to which a predetermined tightening torque is applied in in order to obtain the desired pre-load of the tie rod itself.

In a third embodiment (Figures 9-12) the demolition hammer 1 provides connection units 7 by means of threaded elements of the type described above at the first ends 6a of each tie rod 6 and obstacle connection units 7 'at the second ends 6b.

In this case each obstacle connection unit 7 'has housings 9b placed on the support 4.

In particular, the support 4 is equipped with an opening 17 communicating with each blind hole 12 and accessible from the outside, in which an annular shaped element 10 is inserted complementary to the portion of the opening facing towards the actuator 3 and in which they are defined the housings 9b.

In a fourth embodiment (Figures 13-16) the demolition hammer 1 comprises obstacle connection units 7 'of both ends 6a and 6b of each tie rod 6. More in detail, the obstacle connection units 7' at the first ends 6a are of the type described for the first embodiment, while those provided at the second ends 6b are identical to those of the third embodiment. It should be noted that the various versions of the demolition hammer described above have been designed to be able to provide the obstacle connection units 7 'without intervening on the conformation of the body 2 and of the support 4 already in use and up to now intended for the assembly of threaded tie rods.

In this sense, the present invention can also be incorporated into existing demolition hammers, by replacing the threaded tie rods with those provided with recesses 9a and by introducing the pins 8 and the annular elements 10 if necessary.

The operation of the present invention is entirely similar to that of conventional demolition hammers, since their basic functional groups are not modified.

In practice it has been found that the described invention achieves the proposed aims and in particular it is emphasized that the demolition hammer according to the invention allows to significantly reduce, if not eliminate, the cases of fatigue failure of the tie rods at the ends, increasing its durability and reliability.

Furthermore, the invention can be incorporated into newly manufactured demolition hammers or by intervening on existing demolition hammers by simply replacing the tie rods and connecting elements.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept.

Furthermore, all the details can be replaced by other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the following claims.

Claims (10)

CLAIMS 1) Demolition hammer (1) with optimized resistance comprising a body (2) for containing valve means for distributing a fluid medium to a linear actuator (3) equipped with a piston alternately movable along a direction of percussion and acting on a tool (5) of demolition guided in alternating sliding by a support (4), the body (2) and the support (4) being arranged substantially aligned along the direction of impact with the actuator (3) interposed between them, being also provided a plurality of tie rods (6) for connecting said body (2) and said support (4), each of which has a first end associated with said body (2) and a second end associated with said support (4) by respective connection groups (7; 7 '), characterized in that at least one of said connection groups is of the obstacle type (7'). 2) Demolition hammer (1) according to claim 1, characterized in that said at least obstacle connection unit (7 ') comprises at least one pin (8) arranged transversely to a relative tie rod (6) and engaged in a corresponding seat ( 9) associated with at least the tie rod itself. 3) Demolition hammer (1) according to claim 2, characterized in that said seat (9) is also associated with said body (2) or said support (4). 4) Demolition hammer (1) according to claim 2, characterized in that said seat (9) comprises a transverse hole passing through said tie rod. 5) Demolition hammer (1) according to claim 2, characterized in that said seat (9) comprises a lateral recess (9a) defined transversely on said tie rod (6). 6) Demolition hammer (1) according to claim 3, characterized in that said seat (9) comprises a housing (9b) associated with said support (4) or said body (2). 7) Demolition hammer (1) according to one or more of the preceding claims, characterized in that said at least obstacle connection unit (7 ') comprises an annular element (10) fitted on said tie rod (6) and carrying said housing (9b ), which is associated with said body (2) or with said support (4), the housing (9b) being brought back onto the body (2) or onto the support (4). 8) Demolition hammer (1) according to one or more of claims 1-3 and 5-7, characterized by the fact that said at least obstacle connection unit (7 ') comprises two of said pins (8) arranged parallel to each other from parts opposite of said tie rod (6) and two corresponding seats (9), each of said seats (9) comprising a lateral recess (9a) defined on said tie rod (6). 9) Demolition hammer (1) according to one or more of the preceding claims, characterized in that it comprises one of said obstacle connection units (7 ') at the second ends (6b) of each of said tie rods (6). 10) Demolition hammer (1) according to one or more of the preceding claims, characterized in that it comprises one of said obstacle connection units (7 ') at the first ends (6a) of each of said tie rods (6).