Hammer for an excavator

Abstract

Hammer for excavator comprising a single-body (1) containing a through housing (11) where a proximal bushing (3) and an end bushing (2) are housed; a piston (6) configured to move with reciprocating motion inside said bushings (2, 3); a tool (5), positioned coaxially to said piston so that said piston (6) beats repeatedly on said tool (5) due to its reciprocating motion; a head (8) fastened to said single-body (1) and configured to close said bushings (2, 3) inside said single-body (1), characterized in that said head (8) is fastened to the single-body (1) by means of a plurality of screws (9) passing into through-holes of the flange (8) and screwed in threaded holes realized in the single-body (1) and in that between the proximal bushing (3) and the end bushing (2) an o-ring (20) is arranged configured to guarantee the force transmission axially between the two bushings (2, 3), in addition to the hydraulic sealing.

Description

TECHNICAL FIELD

[0001] The present Patent application for utility model relates to a hammer for excavator provided with a coupling of the various parts to each other which allows its cheaper realization and a faster assembly in comparison to what known at the state of the art.State of the art

[0002] Hammers for excavator are among the various kinds of tools applied to excavators. The hammer is coupled to the hydraulic circuit of the excavator and is commonly used for demolishing rocky and cement material, and for digging.

[0003] A hammer for excavator is generally provided with a hydraulic circuit that, fed with pressurized oil, causes a reciprocating motion of a piston that, by beating repeatedly on the tip of the hammer, allows to obtain demolition.

[0004] It is clear that inside a hammer for excavator parts are provided which move to each other inside an oleodynamic circuit subjected to high pressures.

[0005] According to what known at the state of the art and to what schematically represented in figure 1, the structure of a hammer for excavator comprises: a metal shell with suitable mechanical strength, also called single-body. This one contains a through housing (11) - shown in figure 5 - where one or more inner elements (2, 3) are housed, generally called bushings, inside which, under the action of the pressurized oil a piston (6), configured to beat on a tool (5), and a distribution element, whose reciprocating motion alternatively opens and closes the various ways of the oleodynamic circuits, move.

[0006] The housing (11) is provided with an end hole (12), through which the tool (5) goes out, and at least a stop (12) against which the first bushing (2), introduced therein, is stopped. At the opposite end to the one of the hole (12) from which the tool (5) goes out, the housing (11) of the single-body (1) is closed by a closing flange (8), which in the following is also referred as head. Even if some structural details relating to the realization of the various elements or the arrangement of the oleodynamic circuits can vary, the just described elements are provided in all the breakers for excavator known at the state of the art.Technical problem

[0007] Therefore, it is clear that the coupling of the various elements needs to guarantee both pressure-sealing and mechanical strength of the various elements closed to each other.

[0008] In fact the flange or head (8) rests on the bushings (2, 3) which in turn come in contact with a stop (12) inside the housing (11), and moreover - according to the structural solutions - the flange (8) abuts also against the single-body (1) or against one of the bushings which in turn is in contact with another stop inside the housing (11) inside the single-body (1).

[0009] In both cases, there are two different force transmission chains between the closing flange (8) and the single-body (1) which, for clear reasons linked to the mechanical working tolerances, are made up of elements with different total length. In other terms, there is always a clearance inside one of these two force transmission chains.

[0010] At the state of the art, this problem is solved in different ways, but all of them have some limits. In some cases, the various elements are subjected to mechanical grinding after assembly; in other cases the elements produced are measured and assembled to each other for classes; in other cases a Belleville washer is introduced inside one of the two force transmission chains. Anyway, whatever the solution, the times and costs linked to the realization of the hammer increase. It is also to be specified that, according to what known at the state of the art, the seals of the various elements to each other are all radial type seals.Aim of the utility model

[0011] Therefore, aim of the present utility model is to provide a hammer for excavator, whose coupling exceeds the limits linked to the embodiments known at the state of the art, and in particular which is realized so to not require for the coupling particular mechanical workings and the need to measure and select the pieces after their production.Brief description of the invention

[0012] The invention realizes the prefixed aims since it is a hammer for excavator comprising a single-body (1) containing a through housing (11) where a proximal bushing (3) and an end bushing (2) are housed; a piston (6) configured to move with reciprocating motion inside said bushings (2, 3); a tool (5), positioned coaxially to said piston so that said piston (6) beats repeatedly on said tool (5) due to its reciprocating motion; a head (8) fastened to said single-body (1) and configured to close said bushings (2, 3) inside said single-body (1), characterized in that said head (8) is fastened to the single-body (1) by means of a plurality of screws (9) passing into through-holes of the head (8) and screwed in threaded holes realized in the single-body (1) and in that between the proximal bushing (3) and the end bushing (2) an o-ring (20) is arranged configured to guarantee the force transmission axially between the two bushings (2, 3), in addition to the hydraulic sealing.Description of the figures

[0013] The invention will be now described with reference to the appended figures 1 to 7.

[0014] Figure 1 shows a schematic view of a device of the type known at the state of the art; figures 2, 3, 4 and 5 show section views of the device according to the present utility model; figures 6 and 7 show details, respectively referred to figures 5 and 4.Detailed description of the invention

[0015] With reference to the appended figure 4, the device according to the present model comprises a single-body (1) containing a through housing (11) where two bushings (2, 3) are housed, inside which, under the action of the pressurized oil, a piston (6), configured to beat on a tool (5), moves.

[0016] As it can be noted the end bushing (2), which is also referred as cylinder bushing, is open on both sides, and allows the end of the piston (6) to project to beat the tool (5), while the proximal bushing (3), which is also referred as case bushing, is closed on the top.

[0017] The proximal bushing (3) is closed by a head (8) - which is also referred as closing flange - which in turn is fastened to the single-body (1) by means of a plurality of screws (9) passing into through-holes of the flange (8) and screwed in threaded holes realized in the single-body (1).

[0018] As it is shown in the figures, the proximal bushing (3) abuts both against the single-body (1) and the cylinder bushing (2).

[0019] To solve the previously described problems, the device according to the present model is characterized in that between the proximal bushing (3) and the end bushing (2) an o-ring (20) is arranged.

[0020] The o-ring (20) is configured to guarantee the force transmission between the two bushings (2, 3), in addition to the hydraulic sealing.

[0021] It is observed in fact that the area inside the two bushings is part of the oleodynamic circuit which goes under pressure when the hammer is functioning.

Claims

1. Hammer for excavator comprising - a single-body (1) containing a through housing (11) where a proximal bushing (3) and an end bushing (2) are housed, - a piston (6) configured to move with reciprocating motion inside said bushings (2, 3), - a tool (5), positioned coaxially to said piston so that said piston (6) beats repeatedly on said tool (5) due to its reciprocating motion, - a head (8) fastened to said single-body (1) and configured to close said bushings (2, 3) inside said single-body (1), characterized in that said head (8) is fastened to the single-body (1) by means of a plurality of screws (9) passing into through-holes of the flange (8) and screwed in threaded holes realized in the single-body (1) and in that between the proximal bushing (3) and the end bushing (2) an o-ring (20) is arranged configured to guarantee the force transmission axially between the two bushings (2, 3), in addition to the hydraulic sealing.

2. Hammer for excavator according to claim 1, characterized in that said end bushing (2) is open on both sides, and allows the end of the piston (6) to project to beat the tool (5).

3. Hammer for excavator according to claim 2, characterized in that said proximal bushing (3) is closed on the top.

4. Hammer for excavator according to claim 3, characterized in that said proximal bushing (3) abuts both against said single-body (1) and said cylinder bushing (2).

Images