GB1580651A

GB1580651A - Apparatus for use with a machine tool for damping sound

Info

Publication number: GB1580651A
Application number: GB1210977A
Authority: GB
Original assignee: TORWEGGE MASCHINENFABRIK F
Current assignee: TORWEGGE MASCHINENFABRIK F
Priority date: 1976-03-23
Filing date: 1977-03-22
Publication date: 1980-12-03
Also published as: DE2710361A1; ATA213576A; IT1086729B; ES457070A1; BE852789A; JPS52121899A; AT354721B

Description

(54) APPARATUS FOR USE WITH A MACHINE TOOL FOR DAMPING SOUND (71) We, FRANZ TORWEGGE MAS CHINENFABRIK, a German K. G. of 4970 Bad Oeynhausen, West Germany., do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to apparatus for use with a machine tool for damping sound.

The invention is particularly, but not exclusively, suitable for use with a machine tool having working tools for operation on edge faces of a laminar strip workpiece of wood or plastics.

The invention provides apparatus for use with a machine tool, said apparatus comprising a frame, transport means for moving a workpiece along a path past a working tool of the machine tool disposed at one side of said path, and a sound damping cover means comprising a plurality of serially interconnected sound damping members pivotally movable relative to one another, or a single flexible sound damping member, one end of said cover means being mounted to said frame such that the cover means is movable between a retracted position, in which the cover means is accommodated in a receiving space provided by said frame, and at least one operative position in which, in use, at least a portion of the cover means overlies and is spaced from a workpiece being moved along said path by said transport means on one side of the plane of movement of the workpiece in a region wherein sound is radiated due to the operation of a working tool on the workpiece.

In order that the invention may be well understood some embodiments thereof will now be described with reference to the accompanying drawings in which: Figure 1 is a side view of a wood working machine tool comprising working tools and sound damping cover means, Figure 2 is an end view in partial section of the same machine tool comprising a sound damping cover means covering a workpiece, Figure 3 is an end view in partial section of the sound damping cover means accommodated the receiving spaces, Figure 4 is an end view in partial section of an alternative embodiment of a sound damping cover means in an operative position extended out of the receiving space, and Figure 5 is an end view in partial section of an alternative embodiment of a sound damping cover means in an operative position extended out of the receiving space; and Figure 6 a section through a sound damping member.

A machine frame of a wood working machine tool is referenced 10 in Figure 1. A transport means includes a transport device 12 formed by an endless circulating transport belt, chain conveyor or rollers, and also forms a support for the work pieces 11 to be treated. This transport device 12 defines a path for the workpiece 11 which path lies in an horizontal plane. The transport means also includes a hold-down arrangement 13 which is provided above the said transport device 12, and is formed by a supporting frame 15 adjustable in height with respect to the transport device 12 by adjustment means 14 such as threaded rods, and an endless transport belt 16, transport chain or rollers circulating therearound; this holddown arrangement 13 presses the workpiece 11 on to the transport device 12 and at the same time forms an advancing or transport means together with the transport device.

In a preferred embodiment, the machine frame 10 has two relatively movable opposite side portions 17 each with a transport device 12 and the distance between the side portions 17 is adjustable by means of guides 28 for accommodating different sizes of workpiece.

Above each transport device 12, there is mounted a hold-down arrangement 13. The distance between the supporting frames of the hold-down arrangement 13 is adjustable to correspond with the distance between the side portions 17 so that a side portion 17 and a hold-down arrangement 13 are always vertically aligned.

At least one working tool 18, such as a cutter, miller. saw, or grinder is provided.

Preferably a number of working tools are arranged at intervals behind one another in the direction of advance of the workpiece and are mounted on the side portions 17 and/or the hold-down arrangements 13. The working tools 18 continually operate on the marginal regions of the workpiece 11 passing between the transport belts 12, 16, so as to groove, cut to sizc. grind, or chamfer the workpiece as appropriate.

It will be appreciated that there is a sound radiating region in the area of a working tool which typically may be a hemisphere of radius about 30 cms above the upper surface of the workpiece and about the working point.

In the sound radiating region of the or each working tool 18 there is arranged above and/or below the plane of movement of the workpiece, a sound damping cover means or unit 20 formed from at least one or from a number of serially interconnected sound damping members 19 which are pivotally movable relative to one another.

In an operative position the cover means lies at a relatively small distance from the top or the bottom surface 11a of the workpiece 11.

The sound damping unit damps noise radiated from the workpiece 11 and thus guarantees a noiseless and thus environmentally pleasant method of operation. Each sound damping unit 20 has a receiving space 21 associated therewith and the cover means is at least partially movable thereinto: The receiving space 21 for the sound damping unit 20 arranged above the workpiece 11, is provided by the supporting frame 15. The receiving space 21 for the sound damping unit 20 arranged below the workpiece 11, is provided by one of the side portions 17. All the receiving spaces 21 are of box section open towards the centre of the workpiece and so across the path, thus they are open towards each other and are closed towards the outside (towards the tools 18). For example, the hold-down supporting frame 15 and each of the side portions 17 for forming the receiving spaces 21, has a C cross-section (a box-shape standing on its edge).

Each sound damping unit 20 is composed, in the embodiment of Figures 2 and 3 of three sound damping members 19 pivotally connected to each other. The members 19 are preferaly of block or strip shape. Each sound damping member 19 is formed from a sound damping material, for example from a multi-layer plate, and has an angular, such as rectangular, cross-sectional shape.

The sound damping unit 20 is spaced from the surface of the workpiece to prevent contact therewith and covers the sound radiating region. In this way, sound radiating from the workpiece 11 is damped and a sound damping effect occurs due to the relatively narrow gap 20a thus existing between the workpiece 11 and the sound damping unit 20, especially when the layer 19a directed towards the surface of the workpiece 11 is a sound absorbing layer.

In accordance with the embodiment of Figures 2 and 3, each tool 18 is associated with a cover means 20 comprising three sound damping members 19, pivotally connected to each other by levers 22. One end of the unit 20 is pivotally mounted to the supporting frame 15 or to the side portions 17 respectively by further parallel levers 23.

Each of the three sound damping members 19 is made vertically pivotally and pivotable about an adjacent member by parallel levers (linkages) 22 and the member 19 adjacent to the supporting frame 15 or side portion 17 is pivotally connected to the supporting frame 15 or side portion 17 by parallel levers 23.

In the operative position of each sound damping unit 20 in which it is fully pivoted out of the receiving space 21, the sound damping members 19 lie side by side in a row towards the centre of the workpiece and at a relatively small distance above or below the surface 11a of the workpiece so that the workpiece 11 can pass through between the sound damping units 20 without any frictional contact. Stabilization of the position of the sound damping members 19 is achieved by the parallel levers 22, 23 and by the mutual co-operation of the members 19.

The two members 19 closest to the supporting frame 15 or side portions 17 each have a rounding off and/or chamfer 24 facing the adjacent member 19 and facing away from the surface 1 la of the workpiece so that they may pivot freely relative to one another, only the outermost 19 is formed without such a corner formation. According to the width of the workpiece 11 and thus according to the distance between the side portions 17 and the hold-down arrangement 13, all or only some members 19, are swung out of the receiving space 21 and near to the surface 11a of the workpiece. According to Figure 2, the workpiece 11 is of a width which permits all three members 19 of the opposite sound damping units 20 to be swung out of the receiving space 21. On the right hand side of Figure 2, the position is shown in dotted lines of a further operative position in which the two outer members 19 are pivoted one upon the other, so that all three members 19 are superposed and thus only a narrow region of the workpiece is influenced in a sound damping manner by the members 19.

In Figure 3, the sound damping members 19 are pivoted such that they are stacked one upon the other and are completely retracted into the receiving space 21 and the hold-down arrangements 13 are moved close to one another which, for example, is necessary when the machine tool is operating on a very narrow workpiece 11.

In the swung-out or operative position the levers 23 are located in a stable position due to the mutual co-operation and support on the supporting frame 15 or side portions 17 respectively.

In the embodiment of Figure 4 instead of the pivotal connection between the sound damping members 19 being provided by the levers 22, 23, the members 19 are interconnected by hinges. A displacement guide is also providing moving the cover means 20 between operative and retracted positions.

In this case, the member 19 at the proximal end nearest the side portion 17 or supporting end frame 15 is displaceably retained in a vertical guide such as a groove 25 by means of lateral guide pin 26 and the other sound damping members 19 are each made pivotable with respect to one another and to the said guided member 19 by hinges 27.

By varying the height of the proximal member 19 at the hold-down end or side portion end, the other members 19 are moved to a greater or lesser extent out of the receiving space 21 into the sound radiating region of the workpiece 11 or completely retracted or extended. In so doing, the stable position of the members 19 occurs due to the in mutual co-operation since the hinges 27 are provided on the edges remote from the workpiece 11.

The movement of the members 19 can take place through a draw rope, through a threaded rod or through other suitable means.

The number of sound damping elements 19 in each unit 20 may be as desired or provided corresponding to the particular requirements.

In accordance with the further embodiment illustrated in Figure 5, the sound damping unit 20 is formed by a single flexible sound damping member 19, preferably a mineral fibre plate or a plate of suitable sound damping material.

The supporting frame 15 forming the receiving space 21 has a rectangular crosssection standing on its edge 21a in one long side and lying adjacent to the workpiece 11 (the long side facing the other supporting frame 15). A guide 23, along which the sound damping member 19 is moved into and out of the receiving space, extending in a straight line in the receiving space 21 and has a curved region slightly projecting in a guide lip but of the opening 21a.

At both side faces or laterally within the sound damping member 19, there are arranged a plurality, preferably three, of lateral guide and shaping members or plates 29 having a trapezoidal shape. The two corresponding plates 29 on the two opposite sides of the sound damping member are connected together by connecting rods 30, or all the guide plates 29 each hiive two pins 30 - the rods 30 or pins 30 are carried by each member in the corner region adjacent the shorter parallel edge of the trapezium.

Each of the central guide plates 29 is connected to the adjacent guide plate 29 by an elongate ring 31, which embraces the adjacent pins 30 or rods 30 of the two plates 29 and permits movement of the plates 29 with respect to one another.

Between the adjacent rods 30 or pins 30 of the central plate 29 and the proximal plate adjacent to the guide 28, there is provided a spring means or tension element 32 preferably a tension spring. Movement of the sound damping member 19 out of the receiving space 21 or into the latter may be produced manually or automatically by a draw rope or another suitable movement producing means.

During movement out of the receiving space 21, the sound damping member 19 is moved in an arcuate manner along the guide 28. In its operative position the sound damping member 19 extends at a relatively small distance from the workpiece 11, over or under its surface. Due to the weight of the sound damping member 19, the forward region thereof is continually changed from the arcuate shape - caused by the guide 28, into an horizontal straight shape and movement in this plane form is limited by the forward pins 30 and retaining ring 31 by abutment of the two adjacent pins 30 and the sound damping member 19 cannot therefore fall on to the workpiece 11. The region of the sound damping member which remains in the receiving space its arcuate shape, and is stabilized in the arcuate shape by the tension spring 32, which, due to its point of engagement with the pins 30, hcld the lateral plates 29 together with their inclined sides of the trapezium in engagement with one another.

The length of the sound damping member 19 moving out of the receiving space 21 can be selected in accordance with the desired width of the work and with longer members 19 more plates 29 and if necessary also more tension springs 32 may be provided.

The cross section through a sound damping member 19 illustrated in Figure 6 consists of a housing 33 somewhat rectangular in cross-section, which has a lower flat perforate plate 34. The interior of this housing 33 is filled with a wadding 35 of mineral fibres. Such a sound damping unit has very good sound damping qualities.

It will be appreciated that the abovedescribed apparatus is simple and effective and easily adaptable for use with workpieces having a great variety of widths since the cover means may adopt a number of different operative positions in which it extends to various distances over the workpiece.

WHAT WE CLAIM IS: 1. Apparatus for use with a machine tool, said apparatus comprising a frame, transport means for moving a workpiece along a path past a working tool of the machine tool disposed at one side of said path, and a sound damping cover means comprising a plurality of serially interconnected sound damping members pivotally movable relative to one another, or a single flexible sound damping member, one end of said cover means being mounted to said frame such that the cover means is movable between a retracted position, in which the cover means is accommodated in a receiving space provided by said frame, and at least one operative position in which, in use, at least a portion of the cover means overlies and is spaced from a workpiece being moved along said path by said transport means on one side of the plane of movement of the workpiece in a region wherein sound is radiated due to the operation of a working tool on the workpiece.

2. Apparatus as claimed in claim 1, wherein the sound damping members are stacked one on top of another in the retracted position and lie side by side in the operative postion.

3. Apparatus as claimed in claim 1 or 2, wherein the or each sound damping member comprises a block of sound absorbing material.

4. Apparatus as claimed in any one of the preceding claims wherein four sound damping cover means are provided, two cover means on each side of the plane of movement of the workpiece, the receiving spaces on one side being provided by respective relatively movable opposite side portions of the frame and the receiving spaces on the other side being provided by two supporting frames of a hold-down arrangement of the transport means.

5. Apparatus as claimed in any one of the preceding claims wherein the sound damping members are pivotally interconnected by lever means and said one end of the cover means is mounted to said frame by lever means.

6. Apparatus as claimed in any one of claims 1 to 4, wherein the sound damping members are interconnected by hinges a proximal one of said sound damping members being provided with a guide pin movable in a groove in a wall of the receiving space to move the cover means between its retracted position and the or each operative position.

7. Apparatus as claimed in any one of the preceding claims, wherein the or each receiving space is provided by a box section member having an open side facing across the path.

8. Apparatus as claimed in any one of claims 1, 3, 4 or 7, wherein the cover means comprises a single flexible sound damping member provided with a plurality of lateral guide and shaping members.

9. Apparatus as claimed in claim 8, wherein the receiving space is provided with a guide lip for guiding movement of the sound damping member between the retracted position and the or each operative position, and said guide and shaping members are provided on opposite side faces of the sound damping member each guide and shaping member comprising a trapezoidal plate pivotally connected to the next adjacent member for limited pivotal movement therebetween by means of an elongate ring surrounding a pin carried by each of the members to be connected in a corner adjacent a shorter parallel edge, spring means being provided in association with at least one elongate ring for urging the connected members together, 10. Apparatus as claimed in any one of the preceding claims, wherein the or each sound damping member comprises an housing having a perforate plate along the surface which, when the sound damping member is in an operative position, overlies a workpiece, in use, said housing containing a filling of mineral fibre wadding.

11. Apparatus for use with a machine tool substantially as herein described with reference to Figures 1 and 6 and Figures 2 and 3 or Figure 4 or Figure 5 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The cross section through a sound damping member 19 illustrated in Figure 6 consists of a housing 33 somewhat rectangular in cross-section, which has a lower flat perforate plate 34. The interior of this housing 33 is filled with a wadding 35 of mineral fibres. Such a sound damping unit has very good sound damping qualities. It will be appreciated that the abovedescribed apparatus is simple and effective and easily adaptable for use with workpieces having a great variety of widths since the cover means may adopt a number of different operative positions in which it extends to various distances over the workpiece. WHAT WE CLAIM IS:

1. Apparatus for use with a machine tool, said apparatus comprising a frame, transport means for moving a workpiece along a path past a working tool of the machine tool disposed at one side of said path, and a sound damping cover means comprising a plurality of serially interconnected sound damping members pivotally movable relative to one another, or a single flexible sound damping member, one end of said cover means being mounted to said frame such that the cover means is movable between a retracted position, in which the cover means is accommodated in a receiving space provided by said frame, and at least one operative position in which, in use, at least a portion of the cover means overlies and is spaced from a workpiece being moved along said path by said transport means on one side of the plane of movement of the workpiece in a region wherein sound is radiated due to the operation of a working tool on the workpiece.

9. Apparatus as claimed in claim 8, wherein the receiving space is provided with a guide lip for guiding movement of the sound damping member between the retracted position and the or each operative position, and said guide and shaping members are provided on opposite side faces of the sound damping member each guide and shaping member comprising a trapezoidal plate pivotally connected to the next adjacent member for limited pivotal movement therebetween by means of an elongate ring surrounding a pin carried by each of the members to be connected in a corner adjacent a shorter parallel edge, spring means being provided in association with at least one elongate ring for urging the connected members together,

10. Apparatus as claimed in any one of the preceding claims, wherein the or each sound damping member comprises an housing having a perforate plate along the surface which, when the sound damping member is in an operative position, overlies a workpiece, in use, said housing containing a filling of mineral fibre wadding.