JPH0679652A - Pneumatically reciprocal tool - Google Patents

Abstract

PURPOSE: To provide a pneumatic reciprocating tool using standard industrial material of relatively low cost without deteriorating necessary strength or damage resistance of the tool. CONSTITUTION: This pneumatic reciprocating tool is provided with a cylinder main body 12, and a pneumatic operating piston 110 which reciprocates in the cylinder main body 12 during continuous use, and air is discharged from an air discharge port 24 in the cylinder main body 12 during use. This pneumatic tool is provided with a silencer 126 substantially surrounding the whole body of the cylinder main body 12, and formed out of a long metal hollow structural part, mounting means 128, 130 for mounting the silencer 126 onto the pneumatic tool are provided, and a vibration damping device is provided as desired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tool, and more particularly to silencing and damping of a pneumatic tool.

[0002]

Pneumatic tools are driven by compressed gas. Air is generally used as the compressed gas,
It is not limited to air. In the present specification, the terms "air" and "air tool" each mean "gas in general" unless they are used in different meanings.
Or, it means "pneumatic tool in general".

Pneumatic reciprocating tools such as pavement crushing tools, hammers and riveting machines usually have a metal cylinder body,
A pneumatically driven piston that reciprocates within the cylinder during use of these tools. The cylinder body is provided with one or more exhaust ports for exhausting air during tool use. The piston reciprocates in the cylinder, and at one end of its reciprocating stroke, kinetic energy is shock-transmitted to the axially moving tool tip such as chisel and plow. There is.

[0004]

Since the pneumatic reciprocating tool described above has a structure in which the air after use is discharged into the atmosphere extremely rapidly, it produces a very large noise. Naturally, proposals have been made for the noise protection of these pneumatic reciprocating tools, which are usually in the form of a casing fitted around the tool. FIG. 1 shows an example of a casing mounted around these tools. Although this known type of muffler is made of a resin material and only slightly increases the weight of the overall tool, it has the disadvantages described below. That is, the resin casing has a lower strength than the tool itself and is easily damaged by the rough handling that the tool often receives. Further, the resin material has a problem that it is apt to be damaged or deteriorated due to temperature fluctuation, extremely high temperature, and low temperature.

A further problem with pneumatic reciprocating tools is that they are inherently highly vibrating, which can cause fatigue to the user in a short time and cause physical injury to the user due to long-term use. Linked to the problem of being sexual. Proposals have also been made for this problem to reduce vibration, but there is a problem in that each device is complicated and susceptible to damage during normal use of the tool.

Furthermore, a silencer for a pneumatic reciprocating tool,
Anti-vibration devices (if equipped) generally require specially designed and manufactured components, which can result in a significant cost increase, especially when constructed to withstand the ingress and damage of dirt and dust. There is also a problem. Therefore, in view of the above problems, an object of the present invention is to provide a pneumatic reciprocating tool having a simple structure by itself and having a muffling device that also functions as a protective housing when mounting a vibration isolator. .

[0007]

According to the present invention, a cylinder-shaped main body and a pneumatically driven piston that reciprocates in the cylinder when the tool is in operation are provided, and air is discharged from the exhaust port of the cylinder main body in operation. A pneumatic reciprocating tool for discharging, comprising a hollow metal structure of a certain length having a longitudinal axis substantially parallel to the axis of the cylinder body, and substantially enclosing the cylinder body including its exhaust port. There is provided a pneumatic reciprocating tool further comprising a silencer and a mounting means for mounting the silencer on a pneumatic tool.

The hollow metal structure is usually made of a standard industrial material such as steel and has a square or rectangular uniform cross-sectional shape. The cross-sectional shape of Therefore, this hollow metal structure can be made to have inherently large strength and impact resistance and temperature resistance characteristics by using an inexpensive material as compared with the case of using a special casting or forged product. it can.

Further, since the pneumatic tool according to the present invention is provided with the sound deadening device having the hollow metal structure portion of a constant length, when additionally installing the vibration isolator for connecting the cylinder body and the other part of the tool. Can be provided with a protective housing. Therefore, when a vibration isolation device is additionally installed, it is not necessary for the vibration isolation device itself to withstand mud, dust, and impact, and the vibration isolation device can be designed in consideration of only the vibration isolation function.

Further, since the pneumatic tool according to the present invention has a hollow metal structure portion of a certain length which functions as a protective housing for the cylinder body itself regardless of whether or not a vibration isolator is provided, the cylinder body and the accessory are attached. The air pipe can be manufactured using ordinary metal pipes, and it is not necessary to use a specially shaped casting or forged product having a higher unit price than these ordinary metal pipes, unlike the conventional case. Therefore, according to the present invention, a pneumatic reciprocating tool can be manufactured using relatively inexpensive standard industrial materials without sacrificing the required tool strength and damage resistance.

The mounting means for mounting the silencer on the pneumatic tool may comprise a pair of plates spaced apart along the longitudinal axis of the hollow metal structure. One of the plates is fixed to the fixed length portion of the hollow metal structure portion, and the other plate is not fixed to the hollow metal structure portion but fixed to the cylinder body, Or fixed to a member rigidly fixed to the cylinder body) and loosely fitted within the hollow metal structure.

The one plate fixed to the hollow metal structure is firmly fixed to the cylinder body (or a member firmly fixed to the cylinder body), or the cylinder body (or the member is fixed via an elastic vibration isolator). It is elastically connected to a member that is firmly fixed to the cylinder body. When the one plate is elastically connected as described above, the other plate is slidably installed on the inner surface of the hollow metal structure part via a roller device, and the other plate is The other plate and the cylinder body are made movable along the axis of the hollow metal structure while preventing the cylinder body from rotating around the axis of the hollow metal structure. As a result, even if the one plate and the hollow metal structure portion are elastically connected to the cylinder body by the elastic vibration isolation means, the handle is directly or indirectly attached to the hollow metal structure portion. On the other hand, the force applied by the tool user in the direction of rotating the tool is transmitted to the cylinder body and the tip of the tool rotatably attached to the cylinder body.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Referring first to FIG. 1, this is a British patent specification GB2018904 (and US equivalent US452619).
1) is a sectional front view of a known type of paving crushing tool 10 completely described in 0).

The paving crushing tool 10 basically has a cylinder body 12 whose piston 14 reciprocates when the tool 10 is used. The piston 14 is driven by compressed air introduced through an air inlet 16 under the control of a manually operated throttle valve 18. The automatic switching valve 20 allows compressed air to selectively extend past the piston 14 into the cylinder body 12 (through an air carrying conduit 22).
Allows access to the underside of piston 14 if possible. This alternative introduction of air causes a double reciprocating movement of the piston 14 within the cylinder body 12. The air used is discharged in both directions of piston movement through a central piston-controlled exhaust port 24 formed in the wall of the cylinder body 12.

At the bottom of its operation, the piston 14
Collides with the tappet 26, which transmits the kinetic energy of the piston to a tool bit 28 which is slidably retained in a chuck housing 30 by a latch retainer 32.

A fully joined cylinder end blocker and tool handle 34 is provided for cylinder sealing and for tool 10 use.
It is fastened to the upper end of the cylinder body 12 to function as an operating handle. The handle 34 mounts a pivoting hand lever 36 to control the throttle valve 18 via a push rod 38 and also incorporates an automatic lubricator 40. A hollow plastics sound deadening casing 42 surrounds the exhaust port 24 and thus reduces noise during operation of the tool 10 in the cylinder body 12.
Is fastened to the outer periphery of the lower end of the. However, the plastics sound deadening casing 42 is not as rugged as the rest of the tool 10 (which is basically thickened by alloy drop forging) and the plastic material is susceptible to deterioration by extreme heating and cooling.

The following is a description of various typical non-rugged, but sound-economically economical pavement crushing tools with the option of bespoke forging displacement and / or vibration reduction having a hollow tube of simple construction. Embodiment. Parts of the following examples which are functionally equivalent to or equivalent to the parts of the pavement breaking tool of FIG. 1 are given the same reference numerals,
Therefore, the entire description of those parts is based on the description of FIG. 1 above. If necessary, reference numbers should be given based on the previously mentioned British patent specification GB2018904 (whose reference numbers do not match those used herein).

Referring to FIGS. 2 and 3, these show an air powered pavement breaking tool 100 which constitutes a first embodiment of the present invention. The tool 100 includes a simple bore, the required upper outer shoulder 104, the required lower outer shoulder 106,
And a central exhaust port 24, which is a cylinder body 1 formed of a thick tube body by forging or machining.
Have two. A piece of combined piston and tappet 1
10 reciprocates in the bore of the cylinder body 12, and the tappet portion is guided by a bush 112 held in the bore by a snap ring 114. The upper end of the crushing tool 100 is closed by a compounded end closure and a tool handle 34 which serves as a valve housing for the automatic switching valve 20 and is drilled to provide the necessary air passages. There is. The manually operated throttle valve 18 for driving the crushing tool 100 is not shown in FIG.

Compressed air is introduced from valve 20 toward the underside of piston / tappet 110 by pipe 118 (compared to FIG. 1) which is external to cylinder body 12. The air is then conveyed to the lower end of the bore by a right angle connecting member 120 which is fastened over a side port 122 in the wall of the cylinder body 102 by a steel band 124 that tightly surrounds both the connector 120 and the cylinder body 102. Although band 124 is shown in FIG. 3 as endless, it actually has a connection (eg, a worm gear clip). The vertical cross-section of FIG. 2 is angled obliquely for greater clarity of internal structure details (compared to FIG. 3).

Surrounding the cylinder body 12 is a length of steel SH, which generally has a square cross section (see FIG. 3).
It is a sound deadening casing 126 having S (Structural Hollow Section). Suitable dimensions for the casing 126 are 120 millimeters by 120 millimeters with a wall thickness of 5 millimeters. The muffling casing 126 includes an upper plate 128 and a lower plate 13.
It is mounted on the cylinder body 12 by means of 0, and both plates 128 and 130 are fitted to the inner part of the SHS forming the sound deadening casing 126.

The upper plate 128 is the sound deadening casing 1
It is welded to its inner surface at its outer periphery. The upper plate 128 is centrally attached to the cylinder body 12 by being fastened between the upper outer shoulder 104 and the associated end closure / tool handle 34.

The lower plate 130 is used for the muffling casing 1.
It is loosely fitted in 26 and, unlike the upper plate 128, is not circumferentially attached to the sound deadening casing 126. Instead, the lower plate 130 has a predetermined circumferential clearance 1 from the inner surface of the sound deadening casing 126.
32. The lower plate 130 is centrally attached to the cylinder body 12 by being fastened between the shoulder portion 106 outside the lower portion and the chuck housing 30. An air outlet 134 is formed in the lower plate 130.

The upper plate 128 is the cylinder body 1.
No. 02 mounts the upper end of the sound deadening casing 126, while the lower plate 130 prevents substantial radial actuation of the lower end of the sound deadening casing 126 with respect to the longitudinal axis of the cylinder body 102. Two bolts (not shown) extend between the handle 34 and the chuck housing 30 to hold the tool components together and transfer the tool rotational torque from the handle 34 to the chuck housing 30.

During use of the tool 100, the working air expelled expelled through the central exhaust port 24 is damped within the internal volume of the silencing casing formed by the silencing casing 126 and the end plates 128, 130. Has a pressure pulse. Therefore, the used air is relatively smoothly exhausted through the clearance 132 and the exhaust port 134 leading to the surrounding environment at an inevitably low noise level.

Although the silencer described above has the advantage of being very simple in construction, the inside surface of the silencer casing 126 is provided with a permeable filler material, such as mineral wool, and / or a suitable porous or non-porous material. By providing such a baffle plate, the cushioning efficiency of air pulsation can be improved, and as a result, the silencing effect can be improved.

A further significant advantage is obtained by a muffler in which the muffler casing 126 is formed from a length of steel hollow cross-section structure as shown in FIGS. Such materials, which are standard mechanical materials and therefore economical in raw material cost, are not only robust in nature and resistant to temperature fluctuations, but also on the crushed stone produced by the use of the tool 100. It is also resistant to damage due to shocks that may be caused by the tool 100 dropping or being thrown out. Thus, the silencer casing 126 protects the internal components of the tool 100 against such damage. This protective feature of the silencer casing 126 is designed and manufactured, for example, so that the air conduit 118 has sufficient strength to withstand its pressure without imparting the extra strength required to withstand impact damage. If possible. Thus, the air conduit 118 and cylinder body 12 are formed by a conventional metal tube process, rather than by the relatively laborious and expensive push forging process of the prior art pavement crushing tool shown in FIG. Can be done. Alternatively, the air conduit 118 can be replaced by a length of flexible hose.

A further advantage of the pneumatic tool of the construction shown in FIGS. 2 and 3 is that any indentations or distortions in the silencer casing 126, such as might be caused by impact damage, will be of little or no effect on the proper functioning of the tool 100. It has no effect.

Referring to FIG. 4, there is schematically shown an air powered pavement breaker tool 200 which constitutes a second embodiment of the present invention. In this pavement crushing tool 200,
The same reference numbers are used for similar components to the pavement breaker tool 10 shown in FIG.

The cylinder body 12 of the crushing tool 200 is entirely surrounded by a silencer casing 202, which comprises a length of steel SHS having a generally square cross section. It should be noted that the muffler casing 202 may instead have a rectangular or circular cross section. The silencer casing 202 is closed at its lower end by a welded plate 204,
The plate 204 also functions as a mounting plate by being fixed between the lower end of the cylinder body 12 and the chuck housing 30. A rubber gasket 206 is secured between the upper end of the muffler casing 202 and its associated upper lid or tool handle 34.

When the tool 200 is used, the pulsation of the used air released from the cylinder body 12 through the exhaust port 24 causes the casing 202, the end plate 204, and
It is damped inside the muffler formed by the upper end lid or gasket 206, the back of which is supported by the tool handle 34. This used air is then ejected from the muffler relatively smoothly and relatively quietly via a ventilation outlet (not shown).

SHS for the silencer casing 202
Is used to provide tool 200 with the same functional and structural advantages as described above with respect to tool 100 shown in FIGS. These advantages include providing a silencer casing 202 that is simple in construction, robust, and economical, and that the cylinder body 12 and the air conduit 22 are manufactured by a simple pipe manufacturing process. It includes what you can do.

Referring now to FIG. 5, there is shown a pneumatically powered pavement breaker tool 300 which comprises a third embodiment of the present invention. This tool 300 is generally similar to the tool 100 shown in FIGS. 2 and 3, and in addition to the basic components of the pavement breaking tool described above with respect to FIG.
Is a silencer casing 3 that surrounds the cylinder body 12.
02 and an exhaust port 24. Casing 30
2 is a steel S of a certain length having a generally square cross section
Equipped with HS.

The lower end of the silencer casing 302 is closed by a plate 304 mounted on the lower end of the casing 302 by a pin or welding (not shown). The plate 304 is aligned and stopped between the lower end of the cylinder body 12 and the chuck housing 30. Alternatively, however, the plate 304 could be welded to the cylinder body 12.

The upper end of the silencer casing 302 is closed by an upper plate 306 mounted inside the casing 302 by a pin 308 projecting downward. A sheet-shaped rubber gasket 310 is sandwiched between the lower surface of the upper plate 306 and the upper edge of the casing 302.

Each of the plates 304 and 306 has a lower end portion and an upper end portion of the silencer casing 302, respectively.
Mounted on top, resulting in an assembly in which the components of the tool are attached to each other.

When the tool 300 is used, the pulsation of the air discharged from the cylinder body 12 through the exhaust port 24 is attenuated in the silencer casing 302, and this air is formed on the lower plate 304. Alternatively, it is discharged into the atmosphere through the plurality of holes 312.

Next, referring to FIGS. 6, 7, 8 and 9, an air-powered pavement crushing tool which is a fourth embodiment of the present invention and which has reduced noise and vibration. 400 is shown. In FIG. 6, the outer shape of the basic crushing mechanism 410 is shown by a dashed-dotted line, and this crushing mechanism 410 is essentially the same as the conventional pavement crushing mechanism shown in FIG. 1, for example. The features of the shredding mechanism 410 relating to the present invention and / or different from the prior art are described in detail below.

The upper end of the cylinder body 412 of the crushing tool is no longer closed by a lid member which also functions as a handle, instead a columnar extension member 414 continues above the cylinder body 412. The extension member 414 has a smooth cylindrical outer surface that extends over the main portion in its height direction and a threaded upper end. The outer member 414 has a lateral passage 416 at a height position approximately at the center thereof, which connects the smooth outer surface portion described above to a hollow central hole 418 leading to the automatic switching valve 20. The lateral passage 416 opens into the hollow inner surface of the lateral handle 420, which arrangement is arranged to act as a short range sliding air connection for the purposes described below.

Above the handle 420 and extending member 414
An elastic rubber bushing 422 is mounted around the lock nut 426 screwed onto the threaded upper end of the extension member 414. (Similarly elastically restrained sliding air connections are shown enlarged in FIG. 11, which will be described later.)

The cylinder body 412 of the crushing tool is further provided with a pair of laterally extending brackets 428. The upper lateral support plate 430 carries the lower surface of the handle 420,
The support plate 430 is fitted in a clearance around the extension member 414. A pair of spring assemblies 432 are attached to each bracket 4
28 and the support plate 430. Each spring assembly 432
Comprises a compression coil spring 434 held by a nut and bolt assembly 438 between a support plate 430 and a spring retaining cap 436.

A suitable spring constant for each compression coil spring 434 is 1.97 to 11.8 kg / cm (5 to 30 kg / inch).
Within the range of. The bolt of each assembly 438 is a support plate 430.
Slidably fitted within, so that each spring assembly 432 is
Can be contracted so that each bracket 428 and cylinder body 412 can move toward support plate 430. Each nut and bolt assembly 438 prevents each spring 434 from extending indefinitely. Similarly, the lock nut 426 prevents the cylinder body 412 from moving indefinitely with respect to the support plate 430. During such relative movement, the above-described sliding air connection between the handle 420 and the extension member 414 maintains a continuous and nearly leak-free supply of compressed air from the inside of the handle 420 to the valve 20. To be done.

FIG. 7 shows a conventional air inlet 16, a throttle valve (not shown) and a push rod 38 for operating the throttle valve.
And a hollow handle 420 provided with a throttle control lever 36, all of which are tools 40
0 for supplying and controlling working air. The crushing mechanism 410 having the crushing tubular body 412 and the upper support plate 430 is covered by a sound deadening case 440 formed by a rectangular cross section of an appropriate length. Case 4
The 40 is mounted on the shredder 400 by being welded around a support plate 430 (seen in FIGS. 6 and 8).

In order to improve the mounting of the sound deadening case 440 and to fix it in a straight line, the crusher 400
Also has a lower transverse support plate 442 that is rigidly secured to the lower end of the crushing mechanism 410. Upper support plate 4
30 and the case 440 welded to the elastic rubber bush 4
22 and the correct operation of the spring assembly 432.
All that is necessary to allow movement with respect to the crushing mechanism 410 is that the case 440 can pass vertically around the lower support plate 442, while providing adequate support for lateral movement. And is thus supported against excessive radial movement of the fracturing mechanism 410 longitudinal axis. At the same time, the handle 420 causes the upper support plate 430 to
Is fixed to the extension member 414, but the handle 420 is fixed to the extension member 414 so that the handle 420 is not tilted.
The tool rotation torque applied to 0 is transmitted from the case 440 to the crushing mechanism 410 by the lower support plate 442.

Vertical freedom with lateral restraint,
These simultaneous requirements for torque transmission are due to the mounting rollers 4 at each corner of the lower support plate 442 (seen in FIG. 9).
Is contacted by the roller 44.
Aligned and mounted so as to run vertically along the inside corners of the rectangular SHS forming case 440 (only one such roller is shown in FIG. 6). Although not shown, it is also envisioned that roller 444 could be replaced by a rotating sphere structure. The conical cover 446 is
In order to hold the upper part of the crushing mechanism 410, the case 4
Cover the crushing tool 400 as a cover over 40.

In the operation of the crushing tool 400, the cylindrical body 4
The air discharged from 12 enters the muffler around which is formed by the case 440, the upper support plate 430, and the lower support plate 442. The vibration of the air is weakened in the muffler and surrounds the lower support plate 442 and surrounds the muffler case 44.
Through the gap between 0 (as seen in FIG. 9), it is discharged to the surrounding surroundings relatively smoothly and with relatively low noise (compared to unsilenced discharge). In addition, an air discharge part (not shown) is alternatively formed on the lower support plate 442 and / or the muffling case 440.

During the downward stroke of the piston in the barrel 412 (not shown in FIG. 6, but shown in detail in FIG. 1), the crushing mechanism 410 is pushed upward. The crushing tool 428 protruding from the tubular body 412 abuts the bolt head of the nut and bolt assembly 438 so as to lift the spring retaining cap 436 so that the coil spring 434 contacts the underside of the upper support plate 430. Contact.
This elastic coupling of the crushing mechanism 410 to the upper support plate 410 and to the tool handle 420 fixed to the plate 430 dampens the impulsive movement of the crushing mechanism 410 and thus the vibrations transmitted to the handle 420. To reduce. The user of the tool consequently experiences less mechanical vibration while reducing acoustical disturbances.

The rubber bushing 422 damps the rebounding vibration to further reduce the vibration. Hollow handle 42
The sliding air connection described above between 0 and the extension member 414 allows for proper movement between the fracturing mechanism 410 and the handle 420, which is necessary to dampen vibration while compressing between them. It carries a stream of air that has been trapped. The structures of FIGS. 6-9 thus provide both noise and vibration reduction, as well as the inherent protection of elastic mounting, in a simple, robust, and inexpensive assembly, so that essentially It need not be made or assembled into a shock resistant shape.

FIGS. 10, 11 and 12 show three additional structures, each providing vibration reduction and noise reduction combined with loss resistance. These three structures are
Each is generally similar to the structure shown in FIG.
It has been described in detail above with reference to FIGS. The sound deadening case is attached to the upper support plate around which the welding is performed,
Further, it is basically the same in that it is a hollow cross section of a square (or rectangular) structure which is not fixed to the sound deadening case but is supported by the lower support plate fixed to the crushing mechanism. In many cases, the tool handle is fixed on the upper side of the upper support plate. In each structure, the fracturing mechanism has an automatic variable valve slidingly connected to the hollow central portion of the tool handle to form a sliding connection for compressed air, having an inner air passage and projecting upwards. It has an extension member. Further, in each of the structures of FIGS. 10 and 11, the centrally mounted crushing mechanism is elastically connected to the handle assembly, the upper support plate, and the sound deadening case. This elastic connection forms a means of vibration reduction and comprises one or more coil compression springs, but other shapes of elastic connection can be used, for example metallic or non-metallic. The elastic connection in both constructions further comprises an annular rubber bushing, whereby the upper end of the extension piece holds the tool handle down. (A slightly different shape with reduced vibration is used in the structure of FIG. 12 and is described below.)

Considering the similarity to the structures of FIGS. 6 to 9,
To avoid repetition, the following detailed description of the structures of FIGS. 10, 11 and 12 concentrates on the important detailed differences.
Components and assemblies in the structure of FIGS. 10, 11 and 12 that are the same as or functionally equivalent to the components and assemblies in FIGS. 6 to 9 have the same reference numbers used in FIGS. As given, the '4's are replaced by'5's,'6's,or'7's respectively, and the traditional components resulting from the structure of Figure 1 have invariant reference numbers. Therefore, a detailed description of any part of the structure of FIGS. 10, 11 or 12 is not given below, and FIGS.
The relevant part of the description of is referred to.

With particular reference to FIG. 10, this schematically illustrates a pavement breaker tool 500 forming a fifth embodiment of the invention. Instead of the support member 428 of the crushing tool 400 of FIG. 6, the extension member 514 has a coil compression spring 534.
It is formed with a shoulder near its lower end for abutting the lower end. The lower support plate 542 is a free roller and is slidably mounted within the sound deadening case 540 for lateral restraint and torsional connection of the case 540 to the shredding mechanism 510. The pavement crushing tool 500 is shown in FIGS.
Similar to the fracturing tool 400 of the present invention, it functions to provide noise reduction and vibration reduction.

Returning to FIG. 11, this shows a portion of the pavement crushing tool 600 which constitutes a sixth embodiment of the present invention. The crushing tool 600 is very similar to the crushing tool 400 (compare FIG. 4 with FIG. 11) and the substantial detailed differences are:
Mainly asymmetrical structure in the crushing tool 600 and a retaining bolt 65 for fixing the extension member 614 to the chuck holder 30.
0 (only one shown in FIG. 11) is provided.

Finally, returning to FIG. 12, this shows a pavement breaking tool 700 which constitutes a seventh embodiment of the invention. The crushing tool 700 is the crushing tool 5 shown in FIG.
00, but differ significantly in the means provided to reduce vibration. Compared to the structure of FIG.
In the crushing tool 700, the coupled upper end tubular lid and the automatic variable valve housing (715 in FIG. 12) are different components and are relatively movable with respect to the extension member 714. The tubular lid / valve housing 715 includes an extension member 7
A sliding seal is provided around the lower end of 14. The lid / housing 715 is prevented from being pulled or pushed away from the lower end of the extension member 714 by an integral shoulder or flange 760 provided on it.

The extension member 714 itself has an air passage 71.
It consists of two parts, a lower tubular element 762 having 6 and 718, and an upper threaded stud 764, the upper threaded stud 764 having its lower end screwed onto the upper end of the tubular element 762. The nut 726 is the extension member 71.
4 to elastically restrain against removing any limited downward movement with respect to the handle 720,
It acts through a washer 724 and an elastic rubber bush 722. Upward movement of the extension member 714 with respect to the handle 720 is completely prevented by adjustment of the upper end of the tubular element 762 at the portion of the handle 720 surrounding the hole for the stud 764.

The lid / housing 715 moves over a portion of the piston in consideration of dampening the vibration of the crushing tool 700, and the lid / housing 715 is extended by the inverted piston / cylinder arrangement. Sliding on the relatively stationary tubular element 762 of member 714 is important. The cross-sectional portion of tubular element 762 is removed from the upper surface portion of "piston" 715.

Thus, during operation of the breaker 700 having an internal air passage between the throttle valve 18 and the switching valve 20 filled with compressed air, this reservoir air pressurization of the lid / housing 715 causes its "piston" to move. Affects the area difference,
Housing 715 and breaker mechanism 7 attached thereto
Try to give a net downward bias to the rest of 10. Therefore, the upward impact motion of the breaker mechanism 710 is elastically counteracted by the pneumatically introduced downward biasing force, and the mechanical spring 534 in the breaker 500 of FIG. Resulting in vibration damping.

The downward recoil of the breaker mechanism 710 is via the extension piece 716 and the shoulder 760 when the lid / housing 715 slides down the tubular element 762 into contact with the bottom 760. The acting rubber bushing 722 is elastically limited and damped. The muffler casing 740, as in the previous embodiment, is constructed of an elongated hollow structural part, which provides for noise reduction in the same way.

Thus, seven exemplary embodiments of the invention have been described, all of which result in noise reduction and / or vibration reduction by means of a simple, robust and economical method in itself. In addition, it also makes it possible to easily obtain any structure of the pneumatic tool as a whole from a relatively inexpensive material without reducing the essential strength and impairing the resistance force. While certain variations and modifications of the invention have been described,
The present invention is not limited to this, and other modifications and changes can be adopted without departing from the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view of a known type of pavement breaking tool having a casing covered with plastic.

FIG. 2 is a cross-sectional side view of essential parts of a first embodiment of a pneumatic tool according to the present invention.

3 is a plan cross-sectional view of the first embodiment taken along the line III-III of FIG.

FIG. 4 is a schematic cross-sectional side view of a second embodiment of the pneumatic tool according to the present invention.

FIG. 5 is a cross-sectional side view of essential parts of a third embodiment of the pneumatic tool according to the present invention.

FIG. 6 is a schematic sectional side view (partially shown in phantom) of a fourth embodiment of a pneumatic tool according to the present invention.

FIG. 7 is a front view of the fourth embodiment.

8 is a plan cross-sectional view of the fourth embodiment taken along the line VIII-VIII of FIG.

FIG. 9 is another plan sectional view of the fourth embodiment taken along the line IX-IX of FIG. 6.

FIG. 10 is a schematic sectional side view of the first embodiment of the pneumatic tool according to the present invention.

FIG. 11 is a cross-sectional side view of essential parts of a sixth embodiment of a pneumatic tool according to the present invention.

FIG. 12 is a schematic cross-sectional side view of essential parts of a seventh embodiment of a pneumatic tool according to the present invention.

[Explanation of symbols]

 10 ... Pavement crushing tool 12 ... Cylinder body 15 ... Piston 16 ... Air inlet 18 ... Throttle valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 591143102 David Thomson Alan England, Glasgow, Gee 73 3 Kew, Lather Glenn, Bloomhill Drive 9 (72) Inventor David Thomson Alan England, Scotland, Glasgow Gee 73 3 3 QH, Luther Glen, Bloom Hill Drive 9

Claims (7)

[Claims] 1. A pneumatic reciprocating tool comprising a cylinder body and a pneumatically actuated piston reciprocating within the cylinder body during continued use of the tool, wherein air is used during said use. In a pneumatic reciprocating tool that is exhausted from the exhaust port of the cylinder body and further surrounds substantially the entire circumference of the cylinder body and includes the exhaust port therein. Is provided with a long metal hollow structure portion substantially parallel to the longitudinal axis of the cylinder body, and a mounting means for mounting the silencer to the pneumatic tool. 2. Pneumatic reciprocating movement according to claim 1, wherein said silencer in the form of a hollow metal structure has a protective casing for any vibration damping device connecting the cylinder body to the rest of the tool. tool. 3. Pneumatic reciprocating movement according to claim 1 or 2, wherein the silencer in the form of a hollow metal part comprises a protective casing for the cylinder body itself and any associated pneumatic introduction mechanism. tool. 4. The mounting means for mounting the silencer to the pneumatic tool comprises a pair of plates spaced from each other along a longitudinal axis of the elongated hollow structural portion, one of the plates being the elongated. Fixed to a hollow structure part, the other of the plates being not fixed to the long hollow structure part but loosely fitted therein and substantially fixed to the cylinder body, fixed to the long hollow structure part; The pneumatic reciprocating tool according to claim 1, wherein one of the plates is firmly fixed to the cylinder body. 5. The mounting means for mounting the silencer to the pneumatic tool comprises a pair of plates spaced from one another along a longitudinal axis of the elongated hollow structural portion, one of the plates being the elongated. Fixed to a hollow structure part, the other of the plates being not fixed to the long hollow structure part but loosely fitted therein and substantially fixed to the cylinder body, fixed to the long hollow structure part; The pneumatic reciprocating tool according to claim 2, wherein one of the plates is elastically connected to the cylinder body through elastic vibration damping means. 6. One of the plates elastically connected to the cylinder body, the other of the plates being rotatably connected to the inner surface of the elongated hollow structure portion by a ball or roller mechanism, and the other of the plates. Plate and cylinder body are movable along the longitudinal axis of the elongated hollow structural portion and substantially prevent rotation of the other plate and cylinder body about the longitudinal axis of the elongated hollow structural portion. Thus, the tool reversal force applied to the tool handle fixed to the long hollow structure portion by the user of the tool is transmitted through the elastic vibration damping means of the one plate and the long hollow structure portion fixed to the plate. A contract that is transmitted to the cylinder body and the tool tip rotatably fixed to the cylinder body regardless of elastic connection to the cylinder body. The pneumatic reciprocating tool according to claim 5. 7. The pneumatic reciprocating tool according to claim 3, wherein the cylinder body is made of a flat metal pipe material.