US3708817A

US3708817A - Buffing and deburring machine

Info

Publication number: US3708817A
Application number: US00127669A
Authority: US
Inventors: W Rhine; F Kiser
Original assignee: Timesavers Inc
Current assignee: Timesavers Inc
Priority date: 1971-03-24
Filing date: 1971-03-24
Publication date: 1973-01-09
Anticipated expiration: 1990-01-09
Also published as: GB1376168A; AU453389B2; GB1376167A; CA933752A; AU3656571A

Abstract

A rotary brush mounted on a power driven spindle which in turn is journaled in a bearing unit that is supported for axial oscillation by a pair of leaf springs, has work fed to it by an endless conveyor located beneath the brush. The bearing unit is axially oscillated by a power driven eccentric.

Description

United States Patent [1 1 1 3,708,817 Rhine et a]. 1451 Jan. 9, 1973 [541 BUFFING AND DEBURRING MACHINE 2,153,295 4/1939 Brogden ..15/17 ux [75] Inventors: Wallace R. Rhine, Stillwater; Fred gm? achtman.... bmh 2,804,723 9/1957 Sweeney ..51/38 [73] Assignee: Timesavers, Inc., Minneapolis,

Primary Examiner-Edward L. Robert [22] Filed: March 24, 1971 Attorney-Ira Milton Jones 21 Appl. No.: 127,669

[57] ABSTRACT [52] US. Cl ..l5/77, 15/21 R, 51/38 A rotary brush mounted on a power driven spindle [51] Int. Cl. ..A46b 13/04 which in turn is journaled in a bearing unit that is sup- [58] Field of Search ..l5/2l 0,77, 88, 102, 21; ported for axial oscillation bya pair of leaf springs, 51/33 R, 38 has work fed to it by an endless conveyor located beneath the brush. The bearing unit is axially oscil- [56] References Cited lated by a power driven eccentric.

UNITED'STATES PATENTS 9 Claims, 9 Drawing Figures 1,484,766 2/1924 Erickson ..l5/77 77 Z 5 1 my :m .Efiw'g [73 7/ PATENTEDJAN 9 I975 3.708.817

sum 1 OF 7 WallacaHFhmq Fwd Wffzspz' PATENTEUJAH 9 197a SHEET 2 [IF 7 um WallaaaHFhmg Fran W/jfzspz' PATENTEDJAK 9 ms SHEET 3 [1F 7 Ila...

@MW Liz-71150972245122;

PATENTEBJAH 9 ms SHEET 5 OF 7 mmmumllmmuunummnwuunIIIIHH @MWW Willem 217717221? g rpd Wffzspr K T116. M.

BUFFING AND DEBURRING MACHINE This invention relates to brushing and deburring machines for cleaning, deburring, buffing, finishing and polishing flat surface of workpieces. While the machine of this invention can handle a wide variety of work, it is especially well adapted for the removal of the many burrs that project from the surfaces of printed surface boards after the boards have been drilled for the reception of circuit components.

It is the object of this invention to provide an improved machine of this type and, at the same time, reduce its cost.

The machine of this invention comprises a rotary brush or polishing drum detachably mounted on a horizontal spindle, and an endless belt conveyor beneath the spindle to carry work through the machine with the top surface thereof at an elevation to be acted upon by the rotary brush or polishing drum. A pair of hold-down rolls press the work firmly against the conveyor as the work is carried through the machine.

To accommodate work of different thicknesses, the distance between the brush spindle and the conveyor, and also the spacing of the hold-down rolls above the conveyor, must be adjustable; and to enable brushes or polishing drums of different diameters to be used, and also to compensate for any reduction in diameter due to wear, the relative positions of the spindle as one entity and the conveyor and hold down rolls as a second entity, must be adjustable.

While provision for these necessary adjustments can take various forms, it is a feature of this invention that the brush spindle is not disturbed in effecting the adjustments. Only the conveyor and the hold-down rolls are adjustably mounted. One adjusting device moves the hold-down rolls up or down with respect to the conveyor, and another adjusting means concomitantly moves both the conveyor and the hold-down rolls towards and from the spindle.

By obviating the need for moving the spindle to achieve the needed adjustments, the mounting of the spindle and its drive is greatly simplified; and, in this connection, a very significant feature of the invention resides in the particular way in which the mounting of the spindle provides for limited axial oscillation of the rotary brush to assure against the formation of parallel scratch lines or apparent scratch marks on the work surface.

To enable such axial oscillation of the brush, the spindle is journaled in bearings that are fixed in a block which, in turn, is carried by a pair of leaf springs. The leaf springs have anchored end portions fixed to the frame of the machine in such a way that the only motion permitted the bearing block as a consequence of flexure of the springs is in a horizontal plane.

Another feature of this invention resides in the fact that the machine may be operated either wet or dry, and in either case those portions of the machine that would be deleteriously affected by the conditions in the zone of action are protected therefrom by the simple expedient of locating the rotary brush and the work supporting and feeding conveyor at one side of an upright wall that forms part of the main frame of the machine, while all of the mechanism that should be protected is mounted onor located at-the other side of the wall.

example of the embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a perspective front view of the machine of this invention;

FIG. 2 is a perspective side view of the machine;

FIG. 3 is a perspective view of the machine taken from substantially the same angle as in FIG. 2, but with the shrouds or housings removed;

FIG. 4 is a perspective view of the rear of the machine, also with the housings removed;

FIGJS is a front view of the machine with the housings removed;

FIG. 6 is a top view thereof, also with the housings removed;

FIG. 7 is a detail sectional view through FIG. 5 on the plane of the line 77;

FIG. 8 is a diagrammatic view illustrating in exaggerated manner the oscillation imparted to the bearing unit supporting the rotary brush; and

FIG. 9 is a perspective view of the nozzles and manifolds by which water or other liquid can be supplied to the zone of action.

Referring to the drawings, it will be-seen that the machine can be considered as having a front section 5 and a rear section 6, separated by a vertical wall 7 that forms part of a main frame 8. The front section constitutes the work performing zone through which the parts or work to be acted upon are carried by an endless conveyor belt 9 to have their top surfaces subjected to the action of a rotary brush 10. The rear section 6 contains the drive mechanism for the brush and the conveyor, and other related mechanism to be described.

The main frame 8, which is conveniently formed as a weldment, comprises a flat bottom 11, the vertical wall 7 and another vertical wall 12 that is joined to the rear face of the wall 7 and projects at right angles therefrom. Both vertical walls are fixed to and rise perpendicularly from the bottom 11.

The endless conveyor belt 9 constitutes part of a work supporting unit designated generally by the nu-- to be appropriately tightened. The other roller 19 is power driven and, for this purpose, has a shaft extension 19' that projects rearwardly beyond the wall.7.

Inasmuch as the elevation of the top surface of work on the work support with respect to the rotary brush and, more particularly, the underside of the brush with which the work is to be engaged-depends upon the thickness of the work, it is essential that there be relative adjustment between the work support and the brush. Also, any change in the diameter of the brush, whether the result of wear or replacement with a brush of different diameter, must be accommodated. To enable this needed adjustment, the work supporting unit 13 is vertically adjustably mounted on the wall 7. For this purpose an upright frame 22 is secured to the rear rail of the horizontal box-like structureof the work support, and slidably connected with the side edges of the wall 7. Up and down adjustment of the work support is effected by a lead screw 24 rotatably, but not longitudinally movably mounted in a bearing 25 at the top of the main frame, and threaded in a nut 27 fixed to the frame 22. A hand wheel 26 at the upper end of the lead screw conveniently enables rotation to be imparted to the screw.

Where the work being handled by the machine is relatively thin sheet material-as, for instance, printed circuit boards-it is important that the work be held down flat against the conveyor. This is the purpose of a pair of hold-down rolls 30. The hold-down rolls are freely rotatably journaled in bearings 31 at the outer ends of arms 32 that are pivotally mounted at the underside of brackets 33. The brackets project forwardly over the conveyor from another frame 35 whichlike the frame 22is vertically slidably mounted on the wall 7. Leaf springs 36 at the underside of the brackets 33 impart a downward bias upon the arms 32 and hence onto the hold-down rolls.

Obviously, of course, the elevation of the hold-down rolls above the work support must accommodate the thickness of the work being handled, and to adjust that elevation an adjusting screw 38 reacts between the

frames

22 and 35. This screw has threaded engagement with a nut 39 fixed to the frame 35 and has an unthreaded upper end portion which is freely rotatably, but non-longitudinally movably journaled in a bearing 40-fixed to the frame 22. A knob 41 on the unthreaded end portion of the screw provides for the application of torque thereto. Thus, by turning the knob, the elevation of the hold-down rolls above the endless conveyor may be adjusted, from a miniumu-which may be zero-to a maximum which, in an actual commercial embodiment of the invention, is 2% inches.

Since it is also important that the work be firmly held against the conveyor belt regardless of the dimensions of the work, the hold-down rolls are adjustable towards and from one another. For this purpose, the brackets 33 from which the rolls are supported have horizontally slidable connections with the frame 35. These connections comprise horizontal guideways 41 on the frame 35 in which mounting flanges 42 on the brackets 33 ride, and clamping bolts 43 to clamp these flanges to the guidewaysthe bolts passing through elongated slots in the flanges and being threaded into tapped holes in the guideways'.

The drive roll 19 of the endless belt conveyor has its front end freely rotatably journaled in a bearing 45 that is mounted on the front rail 14 and, at its rear end, the shaft extension 19' which is of reduced diameterconstitutes or is joined to the output shaft of a gear reduction unit 46 that is mounted on the frame 22 rearwardly of the vertical wall 7. A pulley 47 on the input shaft of the gear reduction unit provides for the application of power to the conveyor belt, as will be later described. For the moment, it should be noted that the gear reduction unit, being fixed to the frame 22, moves up and down with the work supporting unit as its elevation is adjusted.

The brush 10, which may be of any type depending upon the nature of the work to be performed, is detachably mounted on a spindle 48 that projects forwardly of the vertical main frame wall 7 at a fixed elevation. The spindle has its rear end portion journaled in bearings fixed in a bearing block 49; but held against axialdisplacement with respect thereto. The bearing block is supported from the wall 7 by a pair of identical leaf springs 50. The free end portions of the leaf springs are clamped to but spaced somewhat from the axially opposite ends of the bearing block, and their anchored ends are similarly clamped to brackets 51 fixed to the wall 7 at opposite side thereof. The anchored ends of the leaf springs are horizontally adjacent to one vertical edge of a square opening 52 in the wall 7 and the free ends'of the leaf springs terminate short of the opposite edge of the opening. The leaf springs thus straddle the wall 7 and the bearing block passes through the opening 52.

It should be noted that the clamps 53 by which the leaf springs are'anchored to the brackets 51 and to the bearing block, are vertically oriented. It follows, there fore, that the motion of the bearing block, and hence the spindle, which results from flexure of the leaf springs, is constrained to a horizontal plane. The leaf springs thus provide a very practical and simple way of mounting the spindle and a brush thereon for axial oscillation without affecting the elevation of the brush.

The desired axial oscillation of the spindle is produced by an eccentric 54 that is connected with the bearing block by a connecting rod 55. The eccentric is fixed to the upper end of a vertical shaft that protrudes from a gear box 56 mounted on the wall 12 of the main frame. Rotation is imparted to the eccentric through appropriate gearing in the gear box 56, and to provide for the connection of this gearing with a power source, a pulley 57 is fixed to its input shaft.

A single motor 58 which is mounted on the wall 12 of the main frame, provides the power to drive the brush spindle, the eccentric that produces the oscillation of the brush and the belt conveyor. To drive the eccentric and the belt conveyor the shaft of the motor has a pulley 59 which is drivingly connected by a belt 60 with the pulley 47 of the gear reduction unit 46 and the pulley 57 which provides an input for the drive of the eccentric. Since the center-to-center distance between the pulley 47 and the other pulleys over which the belt 60 is trained is variable because of the adjustability of the work supporting unit, a spring loaded belt tightener 61' is provided, the tightener being mounted on a bracket 62 fixed to the back of the main frame wall 7.

Another belt 63 and two paired large and small driv-' ing and driven pulleys on the motor shaft and on the spindle drivingly connect the brush spindle with the motor, to drive the latter at either of two speeds. The belt 63 is tightened by adjustment of the position of the motor on the wall 11, and since the belt need not be severely tensioned, it can be shifted from one pair of As seen in FIGS. 1 and 2, the machine is enclosed within a housing which consists of a rear section 70 and a front section 71. The rear section, which is partially formed by the main frame, houses those parts of the machine that should be protected from the zone of action in which the work is acted upon by the brush. Hence, the drive motor and the drive transmission connecting it with the spindle, the driven roll of the belt conveyor and the eccentric, are located in the rear section. I

The front section of the housing is mounted on the frame 22 which carries the work supporting unit, and hence is raised and lowered with it. It consists of a pan 72 beneath the conveyor and a hood 73 over the brush. The rear wall 74 of the pan is clamped between the rail and the adjacent portion of the frame 22, and the hood has its side and top walls bolted to the frame 22. A door 75 in the front wall of the hood affords access to the brush to enable its removal from the spindle when replacement is desired. To facilitate detachment and reattachment of brushes, a knurled nut 76 threaded on the spindle coacts with a fixed flange to clamp the brush to the spindle.

When the machine is operated dry, the hood interior may be connected with a dust collector (not shown) through an exhaust port 77; and, when operated wet, a drain 78 in the bottom of the pan carries off the liquid employed in the operation. 7

For wet operation, each of the brackets 33 on which the hold-down rolls are mounted has a pair of nozzles 80 mounted thereon and arranged to discharge towards the underside of the brush. The nozzles are secured in manifolds 81 which are bolted to the brackets 33 and connected by hoses with an inlet port 82 in one wall of the hood.

Those skilled in the art will appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims.

We claim: I i

l. A buffing and burnishing machine, wherein work fed through the machine is engaged by the peripheral surface of a rapidly rotating brush, characterized by an axially oscillatable mounting for the brush comprising:

A. a bearing block having bearing means therein;

B. a spindle journaled in said bearing means but restrained against axial displacement with respect thereto, said spindle projecting from the bearing block;

C. a pair of leaf springs, each having one end portion thereof anchored to part of the machine frame and its other end portion fixed to axially spaced surfaces ofthe bearing block, said leaf springs being disposed in flatwise spaced overlying relationship, and by their anchorage being constrained to flexure in a plane containing the spindle axis;

D. means detachably mountingthe brush on the spindle; and

E. power driven oscillating means connected with the bearing block to impart axial reciprocation to it and thereby also axially oscillate the brush.

2. The buffing and burnishing machine of claim 1, further characterized by a power driven belt drive for the spindle to impart rotation to the spindle without interferring with its axial oscillation.

3. A buffing and deburring machine having:

1. a main frame including an upright supporting member with opposite sides;

2. a rotary brush spindle;

3. bearing means in which the brush spindle is freely rotatably but not axially movably journaled;

4. means mounting the bearing means on said upright supporting member with its axis horizontal and, with said brush spindle projecting from one side of said supporting member;

5. a rotary brush mounted on the spindle at said side of the upright supporting member;

6. power drive means at the opposite side of said upright supporting member connected with the spindle to drive the same;

7. a work support at said first named side of said vertical upright supporting member and beneath the brush spindle, to be subjacent the brush on the spindle so that work on the work support can be brought into engagement with the brush;

said machine being characterized in that the mounting means for the bearing means comprises:

A. a pair of leaf springs, each having a fixed end portion anchored to said upright supporting member and a free end portion constrained to move in a horizontal plane towards and from said upright supporting member as said leaf springs are flexed; and

B. means securing the free end portions of the leaf springs to axially spaced portions of the bearing means;

and wherein said power driven means includes reciprocation producing means connected with the bearing means and with the free ends of the leaf springs, to flex the leaf springs and axially reciprocate the bearing means.

4. The buffing and deburring machine of claim 3, further characterized by:

A. hold-down means by which work on the work support is held thereon;

B. common mounting means for the work support and the hold-down means vertically adjustably mounted on said upright supporting member; and

C. means for adjusting the elevation of said common mounting means so that regardless of the diameter of the rotary brush and the thickness of the work, proper engagement between the brush and the top surface of the work can be assured.

5, The buffing and deburring machine of claim 4, wherein said leaf springs are at opposite sides of said upright supporting member, and the bearing means passes through an opening in said upright supporting member.

6. The buffing and deburring machine of claim 5, wherein said reciprocation producing means of the power driven means comprises an eccentric rotatably mounted on said upright supporting member at the same side thereof as said power driven means, a connecting rod connecting the eccentric with the bearing means and'the free ends of the leaf springs, and a driving connection between said power driven means and the eccentric.

7. A buffing and deburring machine, comprising:

A. a main frame having a vertical supporting wall with front and back sides;

B. a rotary brush spindle having a front end portion and a rear end portion;

C. bearing means mounted on said vertical supporting wall and in which the rear end portion of the I brush spindle is journalled with its front end portion protruding forwardly from the front side of said supporting wall;

D. a rotary brush detachably mounted on the front end portion of the spindle;

E. drive means connected with the rear end portion of the spindle to impart rotation to the brush;

F. a frame vertically slidably mounted on said supporting wall;

G. a horizontal work support carried by said frame and projecting forwardly from the front side of said vertical wall beneath the rotary brush; and

H. work hold-down means vertically adjustably mounted on said frame above the work support, to hold work down on the work support as it is acted upon by the rotary brush, the adjustability of the work hold-down means on said frame enabling the maintenance of the correct hold-down pressure on the work regardless of its thicknesses, and the adjustability of said frame on the vertical supporting wall adapting the machine to operation with different diameter brushes without affecting the pressure with which the work is held down on the work support.

8. The buffing and deburring machine of claim 7, wherein said work support comprises an endless belt having a top work carrying stretch and trained about parallel spaced apart rollers journalled in bearings fixed with respect to said frame, and a flat deck fixed with respect to said frame and upon which the top work carrying stretch of the belt rides; and wherein said drive means is mounted on the main frame behind the back side of said vertical supporting wall and is drivingly connected with one of said rollers as well as with the brush spindle.

'9. The buffing and deburring machine of claim 8, wherein said work hold-down means comprises: a pair of idler rollers at opposite sides of the rotary brush; and biasing means acting on said rollers to urge them downwardly towards the top work carrying stretch of the endless belt.

Claims

1. A buffing and burnishing machine, wherein work fed through the machine is engaged by the peripheral surface of a rapidly rotating brush, characterized by an axially oscillatable mounting for the brush comprising: A. a bearing block having bearing means therein; B. a spindle journaled in said bearing means but restrained against axial displacement with respect thereto, said spindle projecting from the bearing block; C. a pair of leaf springs, each having one end portion thereof anchored to part of the machine frame and its other end portion fixed to axially spaced surfaces of the bearing block, said leaf springs being disposed in flatwise spaced overlying relationship, and by their anchorage being constrained to flexure in a plane containing the spindle axis; D. means detachably mounting the brush on the spindle; and E. power driven oscillating means connected with the bearing block to impart axial reciprocation to it and thereby also axially oscillate the brush.

2. a rotary brush spindle;

3. A buffing and deburring machine having:

4. The buffing and deburring machine of claim 3, further characterized by: A. hold-down means by which work on the work support is held thereon; B. common mounting means for the work support and the hold-down means vertically adjustably mounted on said upright supporting member; and C. means for adjusting the elevation of said common mounting means so that regardless of the diameter of the rotary brush and the thickness of the work, proper engagement between the brush and the top surface of the work can be assured.

5. The buffing and deburring machine of claim 4, wherein said leaf springs are at opposite sides of said upright supporting member, and the bearing means passes through an opening in said upright supporting member.

6. The buffing and deburring machine of claim 5, wherein said reciprocation producing means of the power driven means comprises an eccentric rotatably mounted on said upright supporting member at the same side thereof as said power driven means, a connecting rod connecting the eccentric with the bearing means and the free ends of the leaf springs, and a driving connection between said power driven means and the eccentric.

7. A buffing and deburring machine, comprising: A. a main frame having a vertical supporting wall with front and back sides; B. a rotary brush spindle having a front end portion and a rear end portion; C. bearing means mounted on said vertical supporting wall and in which the rear end portion of the brush spindle is journalled with its front end portion protruding forwardly from the front side of said supporting wall; D. a rotary brush detachably mounted on the front end portion of the spindle; E. drive means connected with the rear end portion of the spindle to impart rotation to the brush; F. a frame vertically slidably mounted on said supporting wall; G. a horizontal work support carried by said frame and projecting forwardly from the front side of said vertical wall beneath the rotary brush; and H. work hold-down means vertically adjustably mounted on said frame above the work support, to hold work down on the work support as it is acted upon by the rotary brush, the adjustability of the work hold-down means on said frame enabling the maintenance of the correct hold-down pressure on the work regardless of its thicknesses, and the adjustability of said frame on the vertical supporting wall adapting the machine to operation with different diameter brushes without affecting the pressure with which the work is held down on the work support.

7. a work support at said first named side of said vertical upright supporting member and beneath the brush spindle, to be subjacent the brush on the spindle so that work on the work support can be brought into engagement with the brush; said machine being characterized in that the mounting means for the bearing means comprises: A. a pair of leaf springs, each having a fixed end portion anchored to said upright supporting member and a free end portion constrained to move in a horizontal plane towards and from said upright supporting member as said leaf springs are flexed; and B. means securing the free end portions of the leaf springs to axially spaced portions of the bearing means; and wherein said power driven means includes reciprocation producing means connected with the bearing means and with the free ends of the leaf springs, to flex the leaf springs and axially reciprocate the bearing means.

9. The buffing and deburring machine of claim 8, wherein said work hold-down means comprises: a pair of idler rollers at opposite sides of the rotary brush; and biasing means acting on said rollers to urge them downwardly towards the top work carrying stretch of the endless belt.