GB2256162A

GB2256162A - Centrifugal lapping apparatus.

Info

Publication number: GB2256162A
Application number: GB9111512A
Authority: GB
Inventors: Chao-Tung Lin
Original assignee: LIN CHAO TUNG
Current assignee: LIN CHAO TUNG
Priority date: 1991-05-29
Filing date: 1991-05-29
Publication date: 1992-12-02
Anticipated expiration: 2011-05-29
Also published as: GB2256162B; GB9111512D0

Abstract

Centrifugal lapping apparatus comprises a body stand 1, a cylindrical basin 3, a vertically displaceable lapping barrel 4, a rotary turn table 8 at the bottom of the barrel, and a lid 44 having a rotable disc 46. A convectional circulation current is produced by the complementary action of the turn table 8 and disc 46 to provide an efficient lapping effect on workpieces in the barrel. The polished workpieces are conveyed through an ejection gate and collected in a collecting trough when the lapping barrel is elevated. The finished workpieces are sieved and selected in the collecting trough and automatically guided out and collected. This invention provides a lap with high performance and high quality finish. <IMAGE>

Description

BACKGROUND OF THE INVENTION This invention provides a design of centrifugal lap pinpointing the aspects of workpiece lapping, polishing.

The design possesses the features listed below: Fist, making use of the blending movement of the wedge bars on the turn table to produce a current directly causing the turn lid to rotate. As a result, a convectional, kneading, lapping current is produced to pertinent to pertinent to lapping movement for workpieces in order to elevate the efficiency and quality of polishing and lapping.

Second, making use of the up-down movement of the lapping barrel to drive out finished workpieces is a novel method. Compatible with the rotation of the turn table on the body stand and water current, workpieces and abrasive media are driven out fluently and smoothly.

Third, making use of the convectional recycling water current system, chemicals and wastes produced during lapping are filtered and recycled whereby lapping quality is improved.

Fourth, finished workpieces are automatically selected and collected to increase the efficiency of automation.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the structure and configuration of the invention, illustrative diagrams of a preferred embodiment of the invention are shown as follows: Fig. 1 is the external view of the preferred embodiment of the invention; Fig. 2 is the A-A sectional view of the preferred embodiment of the invention; Fig. 3 is the partial assembly diagram of the invention; and Fig. 4 is a sectional view of the invention, showing the descending configuration of the lapping barrel in operation, DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in Figs 1 & 3, this invention comprises a body stand 1 which includes a lateral collecting trough 2 having an internal sieve and a number of different branch exits for screening and guiding out the workpieces and abrasive media (polishing stone) automatically.At the top part of the body stand 1 a cylindrical basin 3 with an ejection gate 31 situated above the collecting trough 2 for giving out workpieces is fixed. A drain pipe 32 connecting with an ejection trough 11 for abrasive circulation and mixing during lapping is installed at the bottom part of the basin 3. An up-down lapping barrel 4 is secured at the top of the basin 3. It- is a vertically through hollow structure having an inner barrel 41. As shown in Fig 2, the inner barrel barrel 41 is fastened at the top slots of the lapping barrel 4 by the bolts 411 circumscribed. In addition, the inner barrel 41 includes three semi-circular lips 412 located in equal distance on its inner surface which (including three semi-circular lips) is coated with PVC to form a lining 413.

After the inner barrel 41 is assembled into the lapping barrel 4 a taper ring 43 is secured at the top of the inner barrel 41. A window 431 is made on the taper ring 43 for easy inspection of the condition inside the lapping barrel 4.

A lid 44 is located at the top of the taper ring 43 and is axially connected with a turn disk 46 having a central hollow tube passing through the lid 44 and terminating at a rotatory joint 462 whereby the lid 44 is connected with a supplying pipe 51. The other end of the supplying pipe 51 is conducted to a water trough 52 and a chemical trough 53 from which water and abrasive are conveyed into the lapping barrel 4 (inner barrel) by a pump 54. Moreover, the lapping barrel 4 comprises protruding lips 45 on the outer surface for support and up-down movement.

The structure enabling the up-down movement of the lapping barrel 4 is clearly illustrated in Fig 2. The body stand 1 comprises a central bolt 61 which passes through a nut block 62 with three radial arms 63. Each arm 63 is firmly fixed with a vertical rod 64 having the opposite end passing through the body stand 1 and the cylindrical basin 3 and firmly screwed at the protruding lip 45 of the lapping barrel 4. When a motor 65 brings the central bolt 61 into rotation, the nut block 62 is driven up and down along the central bolt 61. Similarly, the lapping barrel 4 is brought into up-down motion by the driven vertical rod 64.

In a distance above and below one of the protruding lips 45, a guiding piece 12 with a pause knob 13 on the inner face is designed to limit the upper and lower displacement of the lapping barrel 4. When the ascending (or descending) lip 45 reaches the guiding piece 12 and touches the pause knob 13 an "off" signal is triggered and sent to the motor 65 to stop the ascending (descending) movement.

In the body stand 1 another independent motor 71 is installed. Through a decelerator 72, the motor 71 drives a chain 73 which transfers the motion to a gear 74 having a downward slot embedding a bearing 75. The upper end of the central bolt 61 is axially inserted in the bearing 75 and is secured by a C-shaped retaining ring 76 on the lower part of the bearing 75 to prevent sloughing off. There is an upward slot on the gear 74 to firmly fix with an axle rod 77 which extends upward through the body stand 1 and the cylindrical basin 3 and ends with a turn table 8.

The structure of turn table 8 is clearly shown in Fig 3. A central pore in the turn table 8 is made for keeping the axle rod 77 in position. A top table 82 is tightly secured onto the upper face of the turn table 8 with a number of downward bolts 821 passing through the vertical through hole 83 of the turn table 8 and is fastened by nuts 84 at the bottom part. The top table 82 and the turn table 8 therefore turn in one piece. Furthermore, three radial wedge bars 822 are situated in identical angle on the upward surface of the to table 82 which (including the wedge bars) is lined with PVC to form a PVC layer 823.

In the structure of blending movement, dispite the wedge bars 822 on the top table 82 and the lips 412 on the inner barrel 41 described above the lid 44 is connected with a turn disk 46 at the rear #art. As illustrated in Fig 2, the turn disk 46 is not connected with power supply and it includes three blending blades 461 separated in equal distance. Three blending rods 441 extend downward from the bottom of the lid 44. The blending rods 441 are assembled by C-shaped retaining ring 76 onto the lid 44 to enable vertical adjustment of the rods 441.

For this invention, when wokpieces are sent into the lapping barrel 4 by opening the lid 44, the location of the lapping barrel 4 is just as that shown in Fig 4 with the lip 45 touching the lower guiding piece 12, and the supplying pipe 51 continues to convey abrasive and water in. At the same time, the rear part of the lapping barrel is not in contact with the cylindrical basin and keeps in a suitable distance to give rooms for the dirt and viscous liquid produced by lapping to drain out of the basin 3 to the ejection trough 11 via the drain pipe 32. After a suitable filter treatment in the ejection trough 11 the treated liquid is pumped to the chemical trough 53 and back to the lapping barrel through the supplying pipe 51. By this recycling circulation, not only the efficiency of the abrasive in the lapping barrel 4 is assured, but also the defect of blackening of the lapping surface causing by re-mixing of the abrasive wastes as in the traditional closed lap is prevented.

When the motor 71 is switched on the turn table 8 is driven which in turn brings the top table 82 into rotation The radial wedge bars 822 on the upper surface of the top table 82 blend the workpieces and chemical mixture to form a blending current. By the blow of the vertical strip 412 on the inner barrel and the turn disk 46, the blending current is caused to become a convectional, kneading, lapping current under which the workpieces will have the ultimate polishing finish. According to experimental result, the polishing efficiency of this invention is higher than that of the traditional vibrating or centrifugal lap by 5 to 10 times. Defects of cracking causing by colliding or crooking are prevented. On the aspects of both production and product quality, this invention gives its excellent performance.

After polishing, motor 65 is turned on to drive central bolt 61 in order to elevate the nut block 62. At the same time the vertical rod 64 pushes the lapping barrel 4 upward causing the protruding lips touching the upper guiding piece 12 as shown in Fig 2. A wider space between the lapping barrel 4 and the cylindrical basin 3 is left to let the workpieces settle onto the cylindrical basin 3. The workpieces are conducted to the collecting trough 2 by opening the ejection gate 31. During the course of workpiece collection, the turn table 8 can be still in rotation and water in supply through the supplying pipe 51 to wash the workpieces. When the workpieces drop into the collecting trough 2 they are filtered and selected by the inner sieve and different branch exits to accomplish workpiece collecting automation.

In addition, the central bolt 61 that drives the lapping barrel 4 and the axle rod 77 that drives the turn table 8 are controlled by two independent motors 65 & 71 which can be turned on separately and do not interfere with each other.

Furthermore, the components that are actually in contact with the workpieces during lapping, such as inner barrel Al and top table 82, are designed in assembly structure and lined with PVC coating to prevent workpieces from scratching.

When PVC coating are worn out after a period of time the aged components like inner barrel, top table are quickly and easily detached and changed.

Claims

WHAT I CLAIMED IS:

1. A recycling circulation type centrifugal lap comprising: a body stand having a lateral collecting trough in which sieves and branch exits are located, a central bolt therein extending through a nut block with a number of arms circumscribed and each arms linked with a vertical rod which passing through the body stand and cylindrical basin and secured onto a protruding lip of a lapping barrel; a set of motor driven device therein to drive an axle rod which extending upward through the body stand and the cylindrical basin, and a turn table firmly fixed onto the cylindrical basin; a cylindrical basin securing on the top of the body stand, comprising an open-close ejection gate on the upper part of the collecting trough, and at the bottom thereof a drain pipe conveying to an ejection trough on the lateral side of the body stand;; a lapping barrel, hollow and through in shape, fitted with an inner barrel with three semi-circular lips equally separately in the inner perimeter thereof, after the inner barrel installed into the lapping barrel a taper ring secured onto the top of the lapping barrel and an open-close lid, axially connecting with a turn disk with three blending blades equally located thereon and connected with three downward extending blending rods, in turn covered on the taper ring; and a turn table installed on the top of cylindrical basin and driven by an axle rod in the body stand, having on the upper surface thereof a top table which including three upward radial wedge bars equally separated to blend the mixture of workpieces and abrasive.

2. A lap as defined in Claim 1, wherein the inner surface of the lapping barrel and the top surface of the turn table are lined with a layer of PVC coating.