AU706377B2

AU706377B2 - Barrel polishing apparatus

Info

Publication number: AU706377B2
Application number: AU45170/97A
Authority: AU
Inventors: Shuji Kawasaki; Akitaka Matsushita
Original assignee: BBF Yamate Corp
Current assignee: BBF Yamate Corp
Priority date: 1996-11-27
Filing date: 1997-11-12
Publication date: 1999-06-17
Anticipated expiration: 2017-11-12
Also published as: CA2220820C; CN1078835C; MX9709152A; DE69729779T2; TR199701398A3; CA2323328A1; TR199701398A2; CN1184018A; EP0845327B1; KR19980042849A; KR100318999B1; EP0845327A2; AU4517097A; EP0956925A1; DE69729779D1; ES2222494T3; CA2323335A1; EP0845327A3; CA2220820A1; EP0956926A1

Description

BARREL POLISHING APPARATUS Background of the Invention Field of the Invention The present invention relates to a barrel polishing apparatus.

Prior Art With the conventional barrel polishing apparatus, each workpiece is subjected to polishing by allowing a polishing medium to flow in a polishing medium receiving container while the workpiece is dipped in the polishing medium received in the polishing medium receiving container.

However, with the conventional barrel polishing apparatus, since each workpiece is dipped in the barrel polishing medium received in the polishing medium receiving container while it is seized immovably, there arises an inconvenience that it is difficult to polish the workpiece in a short time.

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Objects of the Invention The present invention has been made in order to eliminate the 20 inconvenience inherent to the conventional technique as mentioned above.

Therefore, an object of the present invention is to provide a barrel polishing apparatus which assures that an operational efficiency of each barrel polishing operation can be improved.

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Structure of the Invention and Advantageous Effects According to the present invention, the barrel polishing apparatus is constructed such that this apparatus includes a polishing medium receiving container having a polishing medium received therein and a workpiece supporting arm, said polishing medium receiving container includes an upper end opening, said workpiece supporting arm can be rotated about an axis line thereof, and a workpiece can be detouchably attached to the foremost end of the workpiece supporting arm. Thus, as a workpiece and a polishing medium are easy to contact each other, consequently, an operational efficiency of a barrel polishing operation can be improved.

2 In addition, provided that the workpiece supporting arm can forwardly and backwardly be dislocated in the axial direction, each workpiece can be dislocated to assume a low position when it is attached to the workpiece supporting shaft and detached from the same. Thus, the workpiece can more easily be attached to the workpiece supporting shaft and detached from the same.

In addition, when the workpiece supporting arm is turnably displaced in the horizontal direction, the workpiece can easily be located in a suitable position in the polishing medium receiving container.

In addition also, when the workpiece supporting arm is turnably displaced in the horizontal direction, as the workpiece can be located under the condition that the surface of the workpiece to be polished is upwardly inclined in the flowing direction of the polishing medium against the inner side wall or/and the bottom wall of the polishing medium receiving container, flow of the polishing medium can be throttled between the workpiece and the inner side wall or/and the bottom wall of the polishing medium receiving container. Therefore, the pressure to the polishing medium to the surface to be polished of the workpiece can be increased, as "the result, the effect of the polishing can be improved.

Brief Description of the Drawings Figure 1 is a perspective view showing a first embodiment of the present invention; Figure 2 is a perspective view showing an attached/detached state 25 assumed by the barrel polishing apparatus shown in Figure 1; Figure 3 is an illustrative view showing a forward/rearward displacing mechanism employable for a workpiece supporting arm arranged on the workpiece supporting unit shown in Figure 1; Figure 4 is an illustrative view showing a rotating mechanism employable for a reversing plate arranged on the workpiece supporting unit shown in Figure 1; Figure 5 is a sectional view showing a second embodiment of the present invention; Figure 6 is a sectional view showing a third embodiment of the present invention; and Figure 7 is a sectional view showing a fourth embodiment of the present invention.

Description of Preferred Embodiments Figure 1 is a perspective view showing a workpiece supporting unit employable for a barrel polishing apparatus constructed in accordance with a first embodiment of a present invention wherein a workpiece is held in the polishing state, Figure 2 is a perspective view showing the attached/detached state of the workpiece in the barrel polishing apparatus, Figure 3 is an illustrative view showing a forward/backward displacing mechanism for a workpiece supporting arm in the workpiece supporting unit, and Figure 4 is an illustrative view showing a rotating mechanism for a reversing plate in the workpiece supporting unit.

In Figure 1 and Figure 2, reference numeral 9B designates a barrel polishing apparatus, and reference numeral 910 designates a base board for the barrel polishing apparatus 9B. Reference numeral 920 designates a polishing medium receiving container, and this polishing medium receiving container 920 is mounted on the base board 910. The polishing medium receiving container 920 is designed to exhibit a cylindrical configuration so that it can be rotated about a central axis line C by actuating suitable driving means (not shown). Reference numeral 921 designates a polishing medium, and this polishing medium 921 is received in the polishing medium receiving container 920. All kind of normally available material such as ceramic grain 0 ,or the like can be used. Incidentally, a wet type polishing process may be 25 used for practicing a polishing method, and alternatively, a dry polishing process may be used for practicing the polishing method.

Reference numeral 922 designates an upper end opening which is formed at the upper end of the polishing medium receiving container 920, and a workpiece (such as an aluminium wheel for vehicle or the like) W to be described later is dipped in the polishing medium 921 via the upper end opening 922.

Next, reference numeral 911 designates a supporting frame, and this supporting frame 911 stands upright on the base board 910. The supporting frame 911 is caused to extend in the upward direction to reach the substantially upper end of the polishing medium receiving container 920.

Reference numeral 930 designates a reversing plate, and this reversing plate 930 is rotatably mounted on the supporting frame 911 via a rotational shaft 931. This reversing plate 930 can be turned within the range of about 1800 on the basis of rotation of the rotational shaft 931 within the range defined by the state shown in Figure 1 and the state shown in Figure In addition, as shown in Figure 4, a first driving motor 932 is mounted on the supporting frame 911. While the rotational force of the motor 932 is reduced in the decelerated state, the foregoing rotational force is transmitted from a pulley 933 of the first driving motor 932 to a pulley 935 of the rotational shaft 931 via a V belt 934, whereby the reversing plate 930 can reciprocally be turned within the range of about 1800.

Reference numeral 940 designates a supporting bed, and this supporting bed 940 is fixed to the reversing plate 930 via a pair of brackets 941. This supporting plate 940 is mounted on the supporting frame 911 in the forwardly inclined state (it is assumed that the fore end side of a workpiece supporting arm 960 to be described later is represented as a forward direction). It should be noted that the inclination angle of the supporting bed 940 can be adjusted.

"'"Next, a slide plate 950 is arranged on the rear surface of the supporting 20 bed 940 so as to move in the forward/backward direction along the inclined surface of the supporting plate 940. This slide plate 950 can be displaced relative to the supporting bed 940 in the forward/backward direction by actuating a bolt/nut mechanism. Incidentally, reference number 9511 designates a bolt portion in the bolt/nut mechanism arranged on the rear 25 surface of the supporting bed 940, and reference numeral 9512 designates a pair of nut portions arranged on the slide plate 950. When a second driving motor 952 is driven, causing the bolt portions 9511 to be rotated, the nut portions 9512, i.e. the slide plate 950 are displaced in the forward/backward direction by way of threadable engagement of the bolt portion 9511 with the nut portions 9512.

Referring to Figure 1 and Figure 2 again, reference numeral 960 designates a workpiece supporting arm, and as shown in Figure 3, this workpiece supporting arm 960 is caused to project from the slide plate 950.

A workpiece (typically an aluminium wheel for a vehicle) W is detachably attached to the foremost end of the workpiece supporting arm 960 with the aid of an air chuck (not shown) so that the workpiece W is dipped in the polishing medium 821 received in the polishing medium receiving container 920. In addition, a third driving motor 961 is mounted on the slide plate 950.

The workpiece supporting arm 960 can be rotated about an axis line thereof by transmitting the rotational force of the third driving motor 961 to the workpiece supporting arm 960 in the decelerated state. Incidentally, the workpiece supporting arm 960 can intermittently be rotated in the normal direction as well as in the reverse direction.

An operation of the polishing apparatus will be described below.

Firstly, as shown in Figure 2, the reversing plate 930 is arranged outside of the polishing medium receiving container 920 by driving the first driving motor 932, causing the rotational shaft 931 to be rotated (refer to the state as represented by phantom lines in Figure At this time, the fore end part of the workpiece supporting arm 960 assumes an upwardly inclined state. While this state is maintained, an operator places the workpiece W on the foremost end of the supporting arm 960 so as to allow it to be fixed to the supporting arm 960.

Thereafter, as shown in Figure 1, the reversing plate 30 is located inside of the polishing medium receiving container 920 by driving the first driving motor 932, causing the rotational shaft 931 to be rotated, whereby the wheel W is dipped in the polishing medium 921 held in the polishing medium receiving container 920 in the flowing state. Incidentally, while the wheel W is held in the polishing medium 921 in the dipped state, the workpiece supporting arm 960 can fragmentarily be displaced in the vibrative :state. After completion of the polishing operation, the reversing plate 930 is 25 located outside of the polishing medium receiving container 920 by driving the first driving motor 932, causing the rotational shaft 931 to be rotated. At this time, the fore end part of the workpiece supporting arm 960 assumes an upwardly inclined state. While this state is maintained, the operator disconnects the wheel W from the workpiece supporting arm 960, and thereafter, he places a next workpiece on the workpiece supporting shaft 960 so as to allow the next workpiece to be fixed to the workpiece supporting arm 960.

Incidentally, when soft material such as sponge, rubber, soft plastic or the like is used in the polishing apparatus 9B as a polishing medium, each finish polishing operation can be achieved at a high efficiency. Further, soft material may be coated on the surface of each hard grain or each hard small block. The coated hard grain or the coated hard small block can be used as a polishing medium of the aforementioned type. After the barrel polishing operation is completed, surface treatment such as coating, plating, alumite treatment or the like is carried out for the workpiece. All kinds of usually available surface treatment are involved in the concept of surface treatment.

Figure 5 shows a barrel polishing apparatus which is a second embodiment of the present invention. In Figure 5, reference numeral 8B designates a barrel polishing apparatus, and reference numeral 860 designates a driving section for driving the barrel polishing apparatus 8B.

Reference numeral 861 designates a cylindrical polishing medium receiving container, and this polishing medium receiving container 861 is mounted on the driving section 860. The polishing medium receiving container 861 can be rotated about an axis line of the driving section 860 in the circumferential direction by actuating the driving section 860. Reference numeral 862 designates a polishing medium, and this polishing medium 862 is received in the polishing medium receiving container 861. All kind of usually available polishing medium such as ceramic grain or the like can be employed for the polishing medium 862. In addition, a wet type polishing process may be employed for the polishing method, and alternatively, a dry type polishing process may be employed for the polishing method.

Reference numeral 863 designates an upper end opening which is formed at the upper end of the polishing medium receiving container, and a workpiece W to be described later is dipped in the polishing medium 862 via o: the upper end opening 811.

25 Next, reference numeral 870 designates a base board which is integrated with the driving section 860, and reference numeral 871 designates a supporting column which stands upright on the base board 870.

The supporting column 870 is caused to extend in the upward direction to reach the substantially upper end of the polishing medium receiving container 861.

Reference numeral 880 designates an attaching bracket, and this attaching bracket 880 is arranged so as to swing on the supporting column 871. Specifically, the attaching bracket 880 can swing about a point 0 along the vertical surface. Reference numeral 890 designates a supporting bed, and this supporting bed 890 is mounted on the attaching bracket 880 via rotating means 881. With this construction, the supporting bed 890 can swing along the vertical surface together with the attaching bracket 880, and moreover, it can turn or swing about an axis line P by driving the rotating means 881.

Reference numeral 891 designates a supporting member, and this supporting member 891 is arranged on the supporting bed 890 in such a manner as to enable it to move in the forward/backward direction. In addition, reference numeral 892 designates a supporting arm, and this supporting arm 892 is fitted into the supporting member 891 in such a manner as to enable it to move in the forward/backward direction. Reference character W designates a workpiece, and this workpiece W is attached to the foremost end of the supporting arm 892 via an air chuck 893 so as to allow it to be dipped in the polishing medium 862 received in the polishing medium receiving container 861.

An operation of the polishing apparatus constructed in the aforementioned manner will be described below.

Firstly, as shown by phantom lines (one-dot chain lines), the supporting arm 892 is mounted to assume the position where its upper end is located directly above the supporting member 891, and thereafter, it is retracted in the downward direction. While the foregoing state is maintained, the wheel W is fixedly mounted on the upper end of the supporting arm 892 with the aid of the air chuck 893. Thereafter, as shown *by phantom lines (two-dot chain lines), the supporting arm 892 is caused to extend in the upward direction. Then, as shown by solid lines, the supporting arm 892 is caused to swing about a point 0 together with the supporting member 892 and the supporting bed 890 along the vertical 25 surface, whereby the wheel W is dipped in the polishing medium 852 which is held in the flowing state in the polishing medium receiving container 861.

Incidentally, while the wheel W is dipped in the polishing medium 862, the supporting arm 892 can fragmentally be displaced in the vibrative state.

After completion of the polishing operation, the supporting arm 892 is caused to swing about the point 0 in the opposite direction together with the supporting bed 890 along the vertical surface, and then, as shown by phantom lines (two-dot chain lines), the supporting arm 892 is held so as to assume the position where the foremost end of the supporting arm 892 is located directly above the supporting member 891. Thereafter, the supporting arm 892 is retracted in the downward direction to assume the state as represented by phantom lines (one-dot chain lines). While the foregoing state is maintained, the wheel W is disconnected from the foremost end of the supporting arm 892. Subsequently, the aforementioned operational steps are repeated.

Incidentally, when soft material such as sponge, rubber, soft plastic or the like is used as a polishing medium employable for the polishing apparatus 8B, each finish polishing operation can be achieved at a high efficiency. Incidentally, soft material may be coated on the surface of each hard grain or hard small block so as to allow the coated hard grain or the coated hard small block to be used as a polishing medium of the aforementioned type.

After completion of the barrel polishing operation, surface treatment such as coating, plating, alumite treatment or the like is conducted. All kind of normally available material is employable for achieving the surface treatment.

For example, an aluminium wheel useable for a vehicle or the like can be noted as a workpiece employable for carrying out the present invention.

,.to However, the present invention should not be limited only to the aluminium wheel as a workpiece but all products each useable as a workpiece are o involved in the concept of the workpiece in the present invention.

Usually, a wet type polishing method or a dry type polishing method for polishing the polishing surface of a workpiece in the presence of a polishing agent is employed as a polishing method in the present invention.

In this case, the number of buffs useable for carrying out the present invention may be limited only to one. Alternatively, a plurality of buffs may 25 be used for carrying out the present invention. Incidentally, a buff wheel can be noted as one example which represents the buff.

To carry out the present embodiment, an ordinary wet type polishing method and an ordinary dry type polishing method can be employed for practicing the wet type polishing method and the dry type polishing method wherein the surface of a workpiece is subjected to polishing in the presence of a polishing agent fed between the polishing surface of the workpiece and the working surface of the buff wheel.

In addition, to carry out the present invention, any type of barrel polishing method such as a fluid barrel polishing method, a vibration barrel polishing method or the like can be used as a barrel polishing method.

/VT RA&N O<i~ Additionally, any type of usually used polishing agent such as ceramic grain or the like can be employed as a polishing agent.

Further, the barrel polishing operation performed as a preliminary step for the dry type polishing step can be used as a so-called rough polishing operation.

Furthermore, the barrel polishing operation performed as a preliminary step for the wet type polishing operation exhibits the same operational effect as that of the dry type polishing operation, and therefore, it can be used as a so called intermediate polishing step.

Moreover, the barrel polishing operation performed as a post-step for the wet type polishing operation exhibits the same operational effect as that of the wet type polishing operation, and therefore, it can be used as a socalled finish polishing step.

Figure 6 shows a barrel polishing apparatus constructed in accordance with a third embodiment of the present invention.

In Figure 6, reference numeral 710 designates a polishing medium :0:receiving container for a barrel polishing apparatus 74. A polishing medium o (aggregate) 720 is received in the polishing medium receiving container 710.

Incidentally, any kind of usually used polishing medium such as ceramic o S• 20 grain or the like can be employed for the polishing medium 720.

Reference numeral 711 designates an upper end opening formed at the upper end of the polishing medium receiving container 710, and the interior of the polishing medium receiving container 710 is communicated with the atmosphere via the upper end opening 711.

25 Reference numeral 712 designates a polishing medium feeding port, and this polishing medium feeding port 712 is formed at the bottom part of 0000 the polishing medium receiving container 710.

A polishing medium 720 contained in the polishing medium receiving container 710 is caused to naturally fall down via the polishing medium 30 feeding port 712. The intensity of pressure generated by the falling-down of the polishing medium 720 is gradually reduced as the polishing medium 720 is increasingly removed from the polishing medium receiving container 710.

Reference numeral 730 designates a guide sleeve, and this guide sleeve 730 is fitted to the bottom part of the polishing medium receiving container 710 in such a manner as to enable the guide sleeve 730 to be rotated. In addition, reference numeral 731 designates a trumpet-like sleeve, and this trumpet-like sleeve constitutes a part of the guide sleeve 730 arranged at the lower part of the guide sleeve 730. A function of the guide sleeve 730 will be described later.

Reference character W designates an aluminium wheel useable for a vehicle of the like (corresponding to a "workpiece" in the present invention).

This wheel W can be rotated around an axis line 0 while it is vibrated.

Incidentally, when the wheel W is rotated, the guide sleeve 730 inclusive of the trumpet-like sleeve 731 is vibratively rotated.

When the polishing medium 720 is caused to naturally fall down from the polishing medium receiving container 710 toward the surface of the wheel W while this wheel W is vibratively rotated, the polishing medium 720 continuously reaches the surface of the wheel W via the guide sleeve 730 with any substantial gap between the polishing medium receiving container 710 and the guide sleeve 730. The polishing medium 720 is discharged in the downward direction via a plurality of holes 751 and 752.

Incidentally, as mentioned above, the intensity of feeding pressure ~generated by the polishing medium 720 to be fed to the wheel W is reduced as the polishing medium 710 is increasingly removed from the polishing medium receiving container 710. Thus, even though a single kind of polishing medium 720 is employed, the surface of the wheel W can be subjected to rough polishing, and moreover, the surface of the wheel W can continuously be subjected to intermediate polishing and finish polishing.

After the discharged polishing medium 720 is completely discharged o :0 :below the zone located below the wheel W. after the interior of the 25 polishing medium receiving container 710 become empty, the polishing medium 720 is returned again to the polishing medium receiving container 710 by using suitable means (not shown). Thereafter, the wheel W is continuously subjected again to rough polishing, intermediate polishing and ~finish polishing. A practical extent attained by each polishing operation can S 30 be changed by adding pressurised air or water so as to allow the polishing medium 720 to be compressed by the pressurised air or water.

After the barrel polishing operation is completed, surface treatment such as coating, plating, alumite treatment or the like is conducted for the wheel W. All kind of usually available surface treatment process is employable for carrying out the foregoing surface treatment.

According to the third embodiment of the present invention, since the feeding of the polishing medium to the surface of the workpiece is achieved attributable to the natural falling-down of the polishing medium, little noise is generated, and moreover, energy consumption can be minimised.

In addition, according to the third embodiment of the present invention, since the guide sleeve is arranged between the feeding port of the polishing medium receiving container and the surface of the workpiece, the feeding of the polishing medium to the workpiece can be achieved without any loss.

Additionally, when the polishing medium received in the polishing medium receiving container can be compressed by using suitable means (not shown), a practical extent attained by each polishing operation performed for the workpiece can be changed.

Figure 7 shows a barrel polishing apparatus constructed in accordance 15 with a fourth embodiment of the present invention.

In Figure 7, reference numeral 7B designates a barrel polishing apparatus, and reference numeral 760 designates a driving section for driving the barrel polishing apparatus 7B. Reference numeral 761 designates a cylindrical polishing medium receiving container, and this polishing medium 20 receiving container 761 is mounted on the driving section 760. The polishing medium receiving container 761 can be rotated about an axis line of the driving section 760 in the circumferential direction by actuating the driving ":OV section 760. Reference numeral 762 designates a polishing medium, and this polishing medium is received in the polishing medium receiving container 25 761. All kind of usually useable polishing medium such as ceramic grain or the like can be employed for the polishing medium 762. Incidentally, the polishing method can be practiced in accordance with a wet type polishing process or a dry type polishing process.

Reference numeral 763 designates an upper end opening which is formed at the upper end of the polishing medium receiving container, and the workpiece W is dipped in the polishing medium 762 via the upper end opening 763.

Next, reference numeral 770 designates a base board which is integrated with the driving section 760, and reference numeral 771 designates a supporting column which upright stands on the base board 770.

The supporting column 771 extends in the upward direction to reach the substantially upper end of the polishing medium receiving container 761.

Reference numeral 780 designates an attaching bracket, and this attaching bracket 780 is arranged in such a manner as to swing on the supporting column 771. Specifically, the attaching bracket 780 can swing about a point 0 along the vertical surface. Reference numeral 790 designates a supporting bed, and this supporting bed 790 is mounted on the attaching bracket 780 via rotating means 781. Thus, the supporting bed 790 can swing along the vertical surface together with the attaching bracket 780, and moreover, the supporting bed 790 can turn or swing about an axis line P by driving the rotating means 781.

Reference numeral 791 designates a supporting member, and this supporting member 791 is arranged on the supporting bed 790 so as to move in the forward/backward direction. In addition, reference numeral 792 e V. 15 designates a supporting arm, and this supporting arm 792 is fitted to the supporting member 791 so as to move in the forward/backward direction relative to the supporting member 791. It should be noted that the forward/backward direction of the supporting arm 792 is coincident with the forward/backward direction of the supporting member 791. Reference character W designates a workpiece an aluminium wheel useable for a vehicle), and this workpiece W is mounted on the foremost end of the supporting arm 792 via an air chuck 793, whereby the workpiece W is dipped in the polishing medium 762 received in the polishing medium receiving container 761.

25 Next, an operation of the polishing apparatus constructed in the abovedescribed manner will be described below.

Firstly, as shown by phantom lines (one-dot chain lines), the supporting arm 792 is mounted such that the foremost end of the supporting arm 792 is located directly above the supporting arm 792, and thereafter, this supporting arm 792 is retracted in the downward direction. While the foregoing state is maintained, the workpiece W is mounted on the foremost end of the supporting arm 792 by actuating the air chuck 793 so that the workpiece W is fixedly mounted on the supporting arm 792 with the aid of the air chuck 793. Thereafter, as shown by phantom lines (two-dot chain lines), the supporting arm 792 is caused to extend in the upward direction.

Subsequently, as shown by solid lines, the supporting arm 792 is caused to

SRA(

I 7) a'r 13 swing about the point 0 together with the supporting bed 790 along the vertical surface so that the wheel W is dipped in the polishing medium 762 which is held in the flowing state. Incidentally, while the workpiece W is dipped in the polishing medium 762, the supporting arm 792 can fragmentarily be displaced with the swinging state maintained. After completion of the polishing operation, the supporting arm 792 is caused to swing about the point 0 in the opposite direction together with the supporting member 791 and the supporting bed 790 along the vertical surface, the supporting arm 792 is held to assume the upright state with the foremost end thereof located directly above the supporting member 791 as shown by phantom lines (two-dot chain lines), and thereafter, the supporting arm 792 is displaced in the downward direction to assume the state as shown by phantom lines (one-dot chain lines). While the foregoing state is S. maintained, the wheel W is disconnected from the foremost end of the 15 supporting arm 792. Subsequently, the aforementioned operational steps are repeated.

Incidentally, when soft material such as sponge, rubber, soft plastic or the like is used in the form of grain or small block as a polishing material useable for the polishing apparatus 7B, each finish polishing operation can be performed at a high efficiency. Incidentally, soft material may be coated on the surface of each hard grain or hard small block so as to allow it to be used S as this kind of polishing medium.

~After completion of the barrel polishing operation, surface treatment such as coating, plating, alumite treatment is carried out for the workpiece W. All kind of normally employable surface treatment is involved in the concept of surface treatment as mentioned above.

The workpiece W useable for practicing the third embodiment and the fourth embodiment of the present invention may be a workpiece which is preliminarily subjected to surface treatment, and alternatively, it may be a workpiece which is not subjected to any kind of surface treatment.

While the present invention has been described above with respect to preferred embodiments thereof, it should be noted that the present invention should not be limited only to these preferred embodiments but various change or modification may be made without departure from the scope of the present invention as defined by the appended claims.

Claims

1. A barrel polishing apparatus, wherein said apparatus includes a polishing medium receiving container having a polishing medium received therein and a workpiece supporting arm defining a longitudinal axis, said polishing medium receiving container includes an upper end opening, said workpiece supporting arm can be rotated about its longitudinal axis, and a workpiece can be demountably attached to the foremost end of the workpiece supporting arm.

2. A barrel polishing apparatus as claimed in claim 1, wherein said workpiece supporting arm is displaceable forwardly and backwardly in its longitudinal axial direction.

3. A barrel polishing apparatus as claimed in claim 1, wherein said workpiece supporting arm can be turned about a substantially horizontal axis spaced from its longitudinal axis. 15

4. A barrel polishing apparatus substantially as hereinbefore described with reference to and/or as shown in Figures 1 to 4, or Figure 5 or Figure 7 of the accompanying drawings. *t DATED this fourteenth day of April 1999 Mr Akitaka Matsushita, Mr Shuji Kawasaki, BBF Yamate Corporation Patent Attorneys for the Applicant: F.B. RICE CO.