US3916575A

US3916575A - Vibro-gyratory finishing machines

Info

Publication number: US3916575A
Application number: US556849A
Authority: US
Inventors: D Cunningham-Smith
Original assignee: William Boulton Ltd
Current assignee: William Boulton Ltd
Priority date: 1969-02-15
Filing date: 1975-03-10
Publication date: 1975-11-04
Anticipated expiration: 1992-11-04

Abstract

A vibro-gyratory finishing machine in which a resiliently supported annular finishing chamber is vibrated by a motor carrying eccentric weights, there being a dam across the chamber over which the charge is caused to climb due to the vibratory action and which leads to a high level separating and discharge zone. The dam is movable upwardly clear of the chamber by mechanical means and the separating and discharge zone is rigidly fixed at the level of the top of the chamber for communication with the upper end of the dam when the dam is in its lowered position.

Description

Umted States Patent 1191 [111 3,916,575

Smith Nov. 4, 1975 [54] VIBRO-GYRATORY FINISHING MACHINES 3,400,495 9/1968 Balz 51/163 3,407,542 10/1968 McKibben 51/163 [75] Inventor Dav'd cmmngham Stoke on 3,422,577 l/1969 McKibben 51/163 Trent, England 3,423,884 1/1969 Balz 51/163 73 A I 3,466,815 9/1969 Balz 51/163 X Sslgnee 3,514,907 6/1970 Strom 51/163 [22] Flled: 1975 Primary Examiner-Harold D. Whitehead [21] A 1. No.: 556,849 Attorney, Agent, or Firm- Alan H. Levine;

Related U.S. Application Data Breltenfeld & Levme [63] Continuation-impart of Ser. No. 439,186, Feb. 4, [57] ABSTRACT 1974, abandoned, which is a continuation of Ser. No. e 2,357, J 14, 1970, abandoned. A vlbro-gyratory fimshmg machme 1n wh1ch a resiliently supported annular finishing chamber is vibrated [30] F i A li ti P i i D 3y a motor cirryirkllg ecgcentric weilghtls, ttllierehbeing a Fb.l5,1969 U'dK' d amacrosstecam eroyerwlc tecarge S 6 w mg om 8324/69 caused to climb due to the vlbratory action and which 52 leads to a high level separating and discharge zone. {51] PS 8? 24% 1 /33 The eem e meveele eeweeely eleee ef the ehemeee by [58] Field of Search" 51/163, 241/175, 259/72 mechanical means and the separating and discharge zone is rigidly fixed at the level of the top of the cham- [56] References Cited her for communication with the upper end of the dam UNITED STATES PATENTS when the dam is in its lowered position.

1,954,111 4 1934 Wilks 51/8 7 Claims, 3 Drawing Figures US. Patent Nov. 4, 1975 Sheet1 f3 3,916,575

US. Patent Nov. 4, 1975 Sheet 2 of3 3,916,575

US. I Patent Nov. 4, 1975 Sheet 3 of 3 3,916,575

VIBRO-GYRATORY FINISHING MACHINES This is a continuation-in-part of application Ser. No. 439,186 filed Feb. 4, 1974 and now abandoned, which is a continuation of application Ser. No. 2857 filed Jan. 14, 1970 and now abandoned.

The invention relates to vibro-gyratory finishing machines which may be used for grinding, polishing, deburring or similar finishing operations and which effect finishing by means of a vibratory action in the form of a high frequency rotary oscillation about a vertical axis with an upward and downward component in the movement, such action being applied to a charge of workpieces or material, usually mixed with discrete finishing media, contained in the machine. The term workpieces used hereinafter should be construed as referring not only to manufactured components, but also to materials which require to be ground or powdered. The invention is concerned with unloading of such machines and separation of the workpieces from the finishing media.

Unloading of machines of the above kind and separation of the workpieces from the finishing media should preferably be effected automatically rather'than manually. This not only reduces costs in terms of the number of operatives requires to supervise a given number of machines, but enables the entire finishing, separating and unloading operation to be carried out automatically under control of timers. Generally the machines incorporate a treatment chamber which is of annular shape in plan view in order that a charge of workpieces and finishing media may move around the chamber several times under the action of the vibratory movement until the polishing, finishing or like operation has been carried out to the desired degree. It is then necessary in some way to separate the workpieces from the finishing media, discharge the workpieces from the machine and return the media for re-use.

It has been proposed to effect separation of the workpieces and media on a separating screen or sieve located outside the machine, the charge of workpieces and media being transferred from the machine to the separating screen. However, such an arrangement takes up excessive operating space and can result in damage to the workpieces during transfer from the machine to the separating unit. It has therefore been proposed to effect separation within the treatment chamber itself by providing a sloping floor in the chamber and a separating screen which can be brought into communication with the upper end of the floor when a separating and discharge operation is required. At other times the screen is moved clear of the upper end of the sloping floor. This arrangement suffers from the disadvantage that the slope in the floor interferes with the movement of the charge of workpieces and media around the chamber and when the separating screen is not in use the charge falls from the upper to the lower end of the floor during its movement around the chamber which can cause damage to the workpieces.

In order to avoid these difficulties it has been proposed to insert a vertical dam or weir across the treatment chamber in order to cause the charge of workpieces and media to rise on to a separating screen communicating with the upper end of the dam or weir. One

such proposal involves manual insertion of the dam or weir but manual insertion is not satisfactory for the reaproposed hitherto the upper edge of the weir in its operative position extending across the chamber, is below the level of the top of the chamber. Since the separating screen requires to be more or less horizontal, this arrangement is unsatisfactory in that if the screen is disposed at all times at the level of the top of the dam or weir, the charge of parts and media moving round the chamber during the finishing part of the cycle collides with the underside of the screen, thereby causing damage to the parts and interfering with the smooth nature of the movement. It is not possible to overcome this disadvantage by reducing the quantity of parts and media since if the machine is filled below a predetermined level inferior finishing results. Resort has therefore been made to movement of the screen in a vertical direction between a raised position in which the screen is disposed at a level above that occupied by the top of the dam when the latter is in its operative position and a lowered position in which the screen is moved down into the treatment chamber so as to co-operate with the top of the dam for separating and discharge purposes.

This arrangement is unsatisfactory in that a relatively complex mechanism requires to be provided to effect raising and lowering movement of the separating screen. A further disadvantage is that a portion of the outer wall of the chamber requires to be removed to allow the movement of the screen and a removable door must be provided to close this opening when the screen is raised and the charge is moving round the chamber otherwise workpieces and media would fall out of the machine through the opening in the chamber wall.

It has also been proposed to insert a dam or weir into a finishing chamber mechanically from below the chamber. This arrangement suffers from a number of disadvantages. In particular the limited space beneath the floor of the chamber does not permit the dam to be raised to the full height of the chamber so that it is necessary to arrange for the separating screen to be vertically movable as discussed above. In addition insertion of the dam from below requires that it passes through a slot in the floor of the treatment chamber and it is necessary to provide complex sealing arrangements to prevent material from escaping from the chamber through the slot. This is particularly troublesome during wet processing, that is where liquid is introduced into the treatment chamber during the finishing operation. Moreover the tendency for particles of finishing media to be drawn down with the darn or weir can result in jamming of the latter or damage to the seals.

Yet another drawback of machines of this kind arises from the fact that the mechanism for raising and lower ing the dam requires to be accommodated beneath the floor of the treatment chamber and the space available in this region is very limited. Consequently it has been necessary to house part of the mechanism for raising and lowering the dam within the dam itself, so that the latter has been of relatively wide hollow construction. This is a complex arrangement and because of its width the dam or weir does not readily penetrate the charge during movement from its lowered to its raised operative position. Substantial power input is therefore required to overcome the resistance of the charge of workpieces and media in the treatment chamber and move the dam from its lowered to its raised position.

It is an object of the present invention to provide a vibro-gyratory finishing machine in which elevation of the charge of workpieces and media to a high level separating zone may be effected by the insertion of a dam or weir without the advantages attendent upon previously proposed arrangements of this kind.

This object is achieved by the provision of a vibrogyratory finishing machine having the following features:

a. a finishing chamber of annular shape in plan adapted to contain a charge of workpieces to be finished, said chamber having a bottom and opposed side walls;

b. means for subjecting the chamber to a vibratory action in the form of a high frequency rotary oscillation about a vertical axis with an upward and downward component in the movement;

c. vertical guide channels in opposite side walls of the finishing chamber;

d. a dam or weir in the form of a single plate vertically slidably mounted within the guide channels;

e. power means located above the finishing chamber and attached to opposite edge regions of the dam leaving a gap at the central region to allow passage of the charge over the top of the dam between the attachment points;

f. the power means being operable to move the dam between a raised position in which the dam is clear of the chamber and permits progression of the charge around the chamber and a lowered position in which the dam is disposed within and across the chamber to cause the charge to rise up and pass over the central region of the dam;

g. the height of the dam being arranged such that in its lowered position the top edge of the dam is at substantially the same level as the top edge of the chamber; and

h. discharge means rigidly mounted on top of the chamber and positioned to co-operate with the dam when the latter is in its lowered position so as to receive the charge passing over the dam, the discharge means including a separating zone having a perforated floor located over said finishing chamber for separating finishing media from the workpieces.

By virtue of this arrangement the dam enters the chamber from above rather than through a slot in the floor so that no sealing of the floor of the chamber is required. The dam in its lowered position extends to the full height of the treatment chamber and it is therefore possible to provide a separating assembly rigidly mounted on top of the chamber, thereby eliminating the need to provide a mechanism for raising and lowering the separating assembly and avoiding the problem of the charge striking the underside of the assembly during its movement round the treatment chamber. The dam also comprises a simple plate which will easily penetrate the charge and requires relatively low power input compared with a wide darn inserted from below as previously proposed. Mechanical insertion of the dam from above the chamber is possible virtue of I attaching the operating mechanism to the dam at its side edges only so that the charge can pass over the dam between the attachment points to reach the dis- The vibratory action is preferably provided by a motor carried by the chamber and having an output shaft carrying eccentric weights. The eccentric weights are preferably adjustable to enable variation of the vibratory action to suit the nature of the charge.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

I FIG. 1 is a vertical cross-section through a finishing mill;

FIG. 2 is a plan view of the mill; and

FIG. 3 is a section on line Ill-III in FIG. 2.

Referring to the drawings, the mill includes a cylindrical base support 5 on which is supported, by an annular series of compression springs 6, a vibratory assembly consisting of a finishing chamber 7 and a vibrator motor 8. The finishing chamber 7 is annular in plan and of generally U-shape in cross-section throughout its annular length. The inner surfaces of the chamber are provided with a lining 9 of rubber, though other lining materials could be used if desired.

The area enclosed by the annular chamber is fitted with a cylindrical sleeve 10 which depends into the support 5 and is rigidified by braces 11 connected to the base of the finishing chamber 7. Within the sleeve 10 the vibratory motor 8 is supported on an upper and lower annular support rings 12, 13. The motor shaft 14 projects above and below the motor casing and is fitted with relatively angularly adjustable

eccentric weights

15, 16. Due to the provision of these weights and to the resilient mounting of the finishing chamber, rotation of the motor imparts to the chamber a vibro-gyratory action in the form of a high frequency rotaryoscillation about the central axis of the motor and chamber with an upward and downward component in the movement. This causes vibration of the charge together with progression of the charge round the finishing chamber.

A high level separating and discharge assembly is rigidly mounted on the finishing chamber and consists of an enclosed separating zone 20 and an enclosed washing chamber 21 terminating in a discharge opening 22. These parts are of generally tunnel-like configuration having a perforated floor (part of which is indicated at 23 in FIG. 2) at the level of the upper edge of the finishing chamber, vertical' side walls 24, and top guard members or roofs to prevent spillage of charge and wash liquid. The guard member over the separating zone comprises a perforated screen 25 and that over the washing chamber a flat plate 26. The perforated floor is arranged to permit the passage of finishing media therethrough while retaining workpieces thereon. As the separating zone is above the finishing chamber media passing through the floor drop back into the chamber. As the separating zone is rigidly mounted on the finishing chamber it is subjected to the same vibratory movement as the chamber.

As can be seen in FIG. 3, the separating zone floor has 'two levels such that the workpieces fall over a step 23a as they move through the zone. This arrangement is advantageous in cases where the workpieces are hollow or boxlike in construction or contain indentations in which media could lodge. By tumbling the work-' pieces from one level to another they are turned over and any such trapped media are dislodged. A similar arrangement is adopted in the washing zone to remove entrapped washing liquid. In either or both cases the floor could, of course, be flat if desired.

Mounted above the chamber at the separating zone is a housing 30 containing power means in the form of pneumatic piston-and-cylinder devices 31 adapted to raise and lower a dam 32 between an upper position in which it is clear of the finishing chamber and a lower position in which it is disposed across the chamber at the entrance to the separating zone. The piston-andcylinder devices 31 are connected to the top of the dam adjacent the opposite sides thereof, leaving a central opening 33 through which parts and media rising over the darn when the latter is in its lowered position may reach the separating zone. The dam extends to the height of the finishing chamber walls and meets the forward edge of the floor of the separating zone. Thus in the lowered position of the darn the charge is prevented from moving round the finishing chamber past the dam, and instead climbs up and over the dam into the separating zone. When the dam is raised however, the charge can circulate round the finishing chamber as many times as may be desired. The separating zone remains rigidly fixed in position on the top of the finishing chamber irrespective of the position of the dam.

The washing chamber is provided with a series of water sprays 33 under which the workpieces pass after separation from the media, the water draining through the perforated floor 23 into a collecting trough 34 from whence it is discharged.

In order to enable wet processing of workpieces a liquid reservoir 35 is provided from which liquid is drawn by a pump 36 and supplied through a pipe 37 to an arcuate spray pipe 38. The liquid is drawn off through a drain 39 and returned to the reservoir through a filter 40 for recirculation.

Thus in operation of the FIGS. 1 to 3 embodiment, a charge of workpieces and finishing media is placed in the finishing chamber and with the dam in its raised position the vibrator motor 8 is started. The chamber is thus subjected to a vibro-gyratory action of the kind referred to above which vibrates the charge and causes it to progress slowly round the finishing chamber. The vibrations in the charge produce relative movement between the workpieces and media thereby effecting the desired finishing action. The nature of the movement as determined by the relative adjustment of the

eccentric weights

15, 16 together with the type, size and material of the grinding media used and the length of the process time, determine whether the action produced is one of a grinding, de-burrin g, polishing or other nature.

While the dam remains in its raised position the charge continues to progress round the finishing chamber. When it is desired to unload the charge at the end of the treatment the dam is lowered, without requiring stopping of the machine, and the vibration then causes the charge to rise up and over the dam on to the floor of the separating zone. Here the finishing media fall through the perforated floor back into the finishing chamber and the workpieces progress to the washing station and are discharged via the opening 22, the wash liquid being collected in and discharged from the low level trough 34.

It should be appreciated that the machine described above is only one embodiment of the invention and variations and modifications such as will occur to those skilled in the art may be effected without departing 6 from the scope of the invention as defined in the appended claims.

I claim:

1. A vibro-gyratory finishing apparatus including:

a. a finishing chamber of annular shape in plan adapted to contain a charge of workpieces to be finished, said chamber having a bottom and opposing side walls,

b. means for subjecting the chamber to a vibratory action in the form of a high frequency rotary oscillation about a vertical axis with an upward and downward component in the movement,

c. vertical guide channels in opposite side walls of said finishing chamber,

(1. a dam or weir in the form of a plate vertically slidably mounted within said guide channels,

e. power means located above said finishing chamber and attached to opposite edge regions of the damforming plate leaving a gap at the central region to allow passage of the charge over the top of the dam between the attachment points,

f. the power means being operable to move the dam between a raised portion in which the dam is clear of said chamber and permits progression of the charge around said chamber and a lowered position in which the dam is disposed within and across said chamber to cause the charge to rise up and over the central region of the dam,

h. discharge means rigidly mounted on top of the chamber and positioned to co-operate with the dam when the latter is in its lowered position so as to receive the charge moving over the dam, said discharge means including a separating zone having a perforated floor located over said finishing chamber for separating finishing media from the workpieces.

2. A vibro-gyratory finishing apparatus according to claim 1 including at least one step over which workpieces tumble in their passage through the zone.

3. A vibro-gyratory finishing apparatus according to claim 1 wherein said discharge means includes a washing unit provided with sprays arranged to wash the workpieces before discharge and after separation from the finishing media.

4. A vibro-gyratory finishing mill according to claim 3 including at least one step over which workpieces tumble in their passage through the washing unit.

5. A vibro-gyratory finishing mill according to claim 1 wherein said vibratory action is provided by a motor carried by the finishing chamber and having an output shaft carrying eccentric weights.

6. A vibro-gyratory finishing mill according to claim 5 wherein said weights are relatively angularly adjustable about the motor shaft.

7. A vibro-gyratory finishing mill according to claim 1 including means for supplying treating liquid to the charge in said finishing chamber, means for drawing off the liquid at the foot of the chamber and further means for filtering and re-circulating the liquid to the finishing chamber.

Claims

1. A vibro-gyratory finishing apparatus including: a. a finishing chamber of annular shape in plan adapted to contain a charge of workpieces to be finished, said chamber having a bottom and opposing side walls, b. means for subjecting the chamber to a vibratory action in the form of a high frequency rotary oscillation about a vertical axis with an upward and downward component in the movement, c. vertical guide channels in opposite side walls of said finishing chamber, d. a dam or weir in the form of a plate vertically slidably mounted within said guide channels, e. power means located above said finishing chamber and attached to opposite edge regions of the dam-forming plate leaving a gap at the central region to allow passage of the charge over the top of the dam between the attachment points, f. the power means being operable to move the dam between a raised portion in which the dam is clear of said chamber and permits progression of the charge around said chamber and a lowered position in which the dam is disposed within and across said chamber to cause the charge to rise up and over the central region of the dam, g. the height of the dam being arranged such that in its lowered position the top edge of the dam is at substantially the same level as the top edge of the chamber; and h. discharge means rigidly mounted on top of the chamber and positioned to co-operate with the dam when the latter is in its lowered position so as to receive the charge moving over the dam, said discharge means including a separating zone having a perforated Floor located over said finishing chamber for separating finishing media from the workpieces.