US3043057A - Machine for abrasive finishing of contoured or profiled surfaces - Google Patents

Description

ARMYTAGE MACHINE FOR ABRASIVE FINISHING 0F CONTOURED 7 OR PROFILED SURFACES Filed June 20, 1960 July 10, 1962 7 Sheets-Sheet l JulylO, 1962 F. w ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING OF CONTOURED OR PROFILED SURFACES 7 Sheets-Sheet 2 Filed June 20, 1960 July 10, 1962 F. w. ARMYTAGE 3,043,057

MACHINE FOR ABRASIVEI FINISHING OF CONTOURED OR PROFILED SURFACES Filed June 20, 1960 7 Sheets-Sheet 3 y 0, 1962 F. w ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING 0F CONTOURED OR PROFILED SURFACES I Filed June 20, 1960 7 Sheets-Sheet 4 y 10, 1962 F. w. ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING OF CONTOURED OR PROFILED SURFACES Filed June 20, 1960 7 Sheets-Sheet 5 uly 1962 F. w. ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING 0F CONTOURED OR PROFILED SURFACES Filed June 20, 1960 7 Sheets-Sheet 6 July 10, 1962 F. w ARMYTAGE MACHINE FOR ABRASIVE FINISHING 0F CONTOURED OR PROFILED SURFACES 7 Sheets-Sheet 7 Filed June 20, 1960 it is This invention relates to the honing, lapping, polishing or similar abrasive treatment of contoured or profiled surfaces. Heretofore this treatment has been manually controlled so far as the guiding of the abrasive tool or medium and its pressure against the surface and its speed of travel thereover was concerned, and consequently the amount of material removed from the workpiece and the uniformity and quality of the surface finish depended largely upon the skill of the operator.

The object of the present invention is to provide a machine capable of abrasively treating contoured or profiled surfaces without human guidance once it has been set in operation and capable of producing rapidly and accurately a surface finish having a high degree of uniformity.

To this end a machine according to the invention includes means for moving the contoured or profiled surface of the workpiece relative to the abrasive tool or medium, means for traversing said tool or medium over and in contact with said surface so as to treat the whole of the desired area thereof, and hydraulic tracer valve mechanism arranged to be actuated by movement of said tool or medium and thereby to maintain the latter in contact with said surface with a substantially constant predetermined pressure. By these means the abrasive tool or medium itself acts as a stylus or tracer foot and through the tracer valve operates automatically to follow the contour or profile of the surface with a constant pressure.

In order to enable the machine to produce the desired high quality finish on workpieces of widely differing shapes, sizes and surface contours, means are provided for varying independently the speed at which the workpiece is rnoved and the speed at which the abrasive tool or medium is traversed, whereby the relative movement between the tool and the workpiece can be caused to take place. at a speed which ensures the necessary high quality surface finish.

The form of movement given to the workpiece and to the .tool may vary according to the type of work which the machine is required to do. One or both movements might be reciprocatory or rotary, and preferably the combination of movements is arranged to cause the tool to cover the contoured or profiled surface in a non-repeating pattern.

I1 treating workpieces on which the surface extends through 360 or substantially so it is found convenient to rotate the workpiece and to reciprocate the tool across its surface transversely to the path in which the latter rotates.

Provision may also be made for oscillating the workpiece through any suitable included angle up to 360 in order to provide the surface honing to a contour which it is more convenient to deal with in sections, as for instance in a glass container mould which is in two or more parts.

It has been found advantageous to oscillate the hone across the two mating parts separately.

The tool and tracer valve are mounted on a carrier which is slidable in a reciprocatory head under control from the tool actuated valve, and this carrier or the tool itself or both independently is or are adjustable angularly to enable the tool to approach the workpiece surface at the most advantageous angle.

In order that the invention may be clearly understood 3,643,357 Patented July 10, 1962 and readily carried into efiect the same will now be more fully described with reference to and by the aid of the accompanying drawings, which illustrate by way of example one construction of machine (and some modifications thereof) embodying the invention and suited mainly for treating the interior or exterior of workpieces on which the surface to be treated extends substantially around 360.

In these drawings: 7

FIGURE 1 is an elevation of the machine from which the tool and workpiece are omitted.

FIGURE 2 is an end elevation seen in the direction of arrow A in FIGURE 1 but showing a tool and workpiece in position;

FIGURE 3 is a plan of FIGURE 1;

FIGURE 4 is a partial horizontal section on the line IV--IV of FIGURE 1;

FIGURE 5 is a view similar to that in FIGURE 1 of the tool holding and tracer deflecting mechanism mounted with the tracer valve upon a tracer-controlled tool slide;

FIGURE 6 is an end elevation seen in the direc ion of arrow B in FIGURE 5, parts being shown in section;

FIGURE 7 is an underneath plan of the tool holding and tracer deflecting mechanism shown disconnected from the tool slide;

FIGURE 8 is a partial view of modifications showing a reciprocatable work slide for use in place of the rotatable work table and showing a three-station turret which can be used to hold three tools;

FIGURE 9 is a horizontal section on the line IX-IX of FIGURE 8 showing how the tool could operate on a flat workpiece in that instance;

FIGURES 10 and 11 are detail views of adjustable extensions for the tool holder.

Referring first to FIGURES l to 4, the machine has a frame 1 supported on wheels 2 and carrying in its lower part 3 an oil reservoir. An electric motor 4 drives an oil pump '5 which draws oil from the reservoir and pumps it to an oil motor 6 through pipe connections (not shown). The oil motor 6 drives through a V belt 8 and pulleys 7, 9 the shaft 10 of a circular rotatable magnetic worktable 1 1 whose speed can be maintained substantially constant during the honing operation.

The worktable can be rotated in either direction continuously. Alternatively, if desired to suit the workpiece to be treated, the work table can be oscillated under preset control of an oil hydraulic reversing mechanism 12 (see FIGURE 4) whose actuator arm 13 is alternately operated by two dOgs 14 inserted in a reversing disc 15 secured on the work table shaft 10.

Above the worktable is a reciprocatory head 16 vertically slidable upon three pillars 17 by the ram rod 18 of and oil hydraulic ram working in a cylinder 19 mounted with the pillars on the machine frame 1. The ram can be set to reciprocate the head 16 over a predetermined length of stroke at a predetermined substantially constant speed during the honing operation, the oil being supplied to the cylinder 19 by the pump 5. A reversing rod 20 supported by centralising springs 21 in brackets 22, 23 secured respectively to the top of the pillars 17 and to the frame 1 carries two stops 24 having projections 24X engageable by a dog 25 on the head 16. The stops can be roughly adjusted along the rod quickly by a sliding movement or slowly to give accurate adjustment by a micrometer screw. The rod 20 has two pins 26 arranged to operate alternately the actuator bar 27X of an oil hydraulic reversing mechanism 27 mounted in the frame 1. This mechanism 27 and the reversing mechanism 12 can be of any suitable construction, but are preferably constructed and arranged as described and shown in my pending British patent application No. 30,457/58.

variations in the shape of Referring more particularly to FIGURES to 7, the

head 16 carries a saddle 28 having an annular T-sectioned slot 29 in which engage the heads 30 of studs secured in a tracer-controlled tool slide 31. By this means the tool slide 31 can be adjusted angularly relative to the 'head in a vertical plane through 360, although a swivelling movement of about 180 would be suficient to meet most treated.

The saddle 32 of the tool slide 31 is reciprocated by a ram working in an oil hydraulic cylinder 33 in known fashion under control from a tracer valve 34 of a suitable construction similar to those used for automatic hydraulic copying tracers of machine tools, and preferably a valve embodying the constructional features disclosed in my British Patent No. 692,642. The tracer valve is conplied by pipe connections (not shown) to the cylinder 33 and to a source of oil under pressure (independent of the oil pump 5) as will be understood by those skilled in the art. 1 a r The tracer valve is secured by its stem 35 in a bracket 36 which is secured to the saddle 32 by a stud 37 whose axis is parallel to the swivelling axis of the saddle itself. On slackening this stud the bracket can be adjusted angularly relative to the saddle in a vertical plane through The bracket 36 carries a tool-holding and tracer-deflecting mechanism. This consists of a deflector arm 33 pivoted at one end in the bracket by a pivot pin 39 with ball bearings 40 to give maximum freedom fromfriction. The arm near its other end works between two freely rotatable guide rollers 41 which are mounted on the bracket 36 to guide the arm in its vertical movement with the minimum of friction and yet to resist sideways pressure on the arm. Mounted in the bracket 36 is a deflectorspindle 42 whose foot 43 is urged into contact with the arm 38 by a coil spring 43X surrounding the spindle within a 'sleeve 44 which is screwed into the bracket by a knurled head 45 to compress the spring. By this means a pre-determined constant pressure can be exerted upon the deflector arm 38, the downward move ment being limited by a stop pin 46. The spindle 42 carries a nose piece 47 which makes point contact with a stud 48 secured in an arm 49 which is arranged to actuate the spool or equivalent movable member of the tracer valve 34. I u r The deflector. arm 38 has well spaced from its pivot point alternative sockets 50, 50a, 50b, to receive the shank of a honing or like tool 51a in the form of a spindle which extends in the opposite direction to the deflector spindle and which has applied to or secured on its foot, on the side facing towards the deflector arm'pivot and/ or on its end, a stone or'other suitable form of abrasive element. The socket 50b is provided in an L-shaped arm 52 pivoted at 53 on the arm-38 and adjustable through 90 by a clamping stud 54 working in a segmental slot 55.

a As indicatedin FIGURE 5, the socket-50 may be used for internal honing of workpieces such as the bottle mould W1 shown and the socket 50a for external honing of suit able workpieces. 'Alternatively, as shown in FIGURES and 1 1 by securing the tool in an adaptor 56 or 56X which in turn is secured in the socket 50b, the tool 51b or 510 can be made to approach the work at the most suitable angle, that shown in FIGURE 10 being suitable for treating a hemispherical workpiece W2 whilst that shown in PIGURE-11-is suitable *for treating the inside of a cup-shaped workpiece W3. In both these figures the bracket 36 has been angularly adjusted, either by itself or by the angular adjustment of the tracer-controlled tool slide or by the combined angular adjustment of both these members. The combination of these two swivelling movements enables the tool foot to be broughtto bear on the contoured surface from the most advantageous angle in each particular case. a

The operation of the machine is as follows. With the the contoured surfaces to be workpiece held on the worktable '11, the tool foot set conveniently to the contour face to be honed and the stroke of'the head 16 set by the rod 20 to suit the height of such face, the oil pump 5 is started, the speeds of the rotary worktable and of the reciprocatory head are adjusted by the control knobs 60 and 61 which are capable of giving an infinite speed variation over a predetermined range, and honing commences. The tool foot is held against the workpiece surface with a constant pressure which can be predetermined by the setting of the spring 43X, and any increase in' this pressure applied by the contour to the tool foot at any point between w and x (see FIGURES 5, l0 and 11) will move the foot away in the direction of arrow y and operate, through the tracing valve, the tool saddle 32 which will move away in the direction of arrow 1. Similarly any decrease in the pressure of the foot on the surface causes corresponding opposite movements. Thus in effect the tool itself is a sensing head which is traversed over the surface of the workpiece by (in the above example) a combination of rotary and reciprocatory movements at a predetermined speed, whereby the rate of metal removal can be smaller and slower than with other honing or polishing machines, thereby producing a better surface finish with the minimum amount of material removed in the process.

In order to make more certain the movement of the tool over the contoured surface'in a non-repeating pattern, control means may be incorporated in the hydraulic circuit to the head-reciprocating ram to give this ram different speeds on its upward and downward strokes.

By using a single oil pump to supply oil to both the oil motor operating the table and the ram operating the head, the total volumeof oil supplied is divided between these two in the correct proportion to ensure the maximum footage (i.e. area of contoured surface treated per unit time).

The tool on the deflector arm can swing freely about the arm pivot to follow the contour on the workpiece but is guided so as to resist the torque exerted on it by the rotating workpiece. By mounting the tool spindle at apoint cifset from the arm pivot the spindle can yield to lengthwise pressure as well as sideways pressure to operate the deflector arm regardlessof the direction of movement of the reciprocating head at that moment.

If desired, instead of using the single tool as above described, a turret 62 (see FIGURE 8) may be secured in any one of the sockets 50, a, 50b in the deflector arm 38 and adapted to hold (for example) three tools, say a roughing hone, a medium hone and a finishing hone, any one of which can be turned into working position at choice and locked there.

In a modified form of the construction above described (see FIGURES 8 and 9) suited. for treating a flat 1 workpiece W4 onwhich the contours extend across a substantially plane surface so that it is more convenient to reciprocate the workpiece relative to the tool instead of rotating it, a workholding saddle 63 reciprocated by the ram of a hydraulic cylinder 64 is slidable on a workslide 65 secured upon the machine frame 1 instead of the rotary worktable, the latter being immobilised if left in placein the machine. The saddle 63 is mounted so as to be reciprocated in a direction at right angles to that in which the tool slide 31 reciprocates or at any other angle best suited to the contour to be treated in each particular case, and the ram (fed with oil from the oil pump 5) could have its length and speed of stroke varied as previously, described-with reference to the vertical ram to suit each job. Thus a vertical reciproca: tion of the tool 51a and a horizontal reciprocation of the workpiece could bearranged to cover any flat C011? toured area with a non-repetitive pattern, the contoured surface being mounted in a mainly vertical plane. 'In a further modified arrangement (which will be readily understood without illustration), andwith the contoured surface held face upwards on the rotatable worktable, the tracer-controlled tool slide would be swung through approximately 90 compared with its previously described direction so that the variations in the depth or height of the contour would be taken care of by the deflection of the tracing valve through the tool-holding mechanism pressing the tool down onto the contoured surface. In this case an additional ram-operated slide (or the workslide already referred to) may be interposed between the swivelling tracer-controlled tool slide and the vertically reciprocatable head carrying it, whereby the tool can be given a constant horizontal reciprocatory movement suitable for treating (say) convexed or concaved contours 011 a workpiece mounted flat on the rotatable worktable.

I claim:

1. In a machine for the abrasive finishing of contoured surfaces of workpieces, the combination of an abrading tool, means for holding a workpiece, means for moving said workpiece and holder for cutting movement relative to saidabrading tool, means for holding said abrading tool and for traversing it over and in contact with the contoured surface of said workpiece to thereby treat the whole of the desired area thereof, a hydraulic tracer valve mechanism mounted to be traversible with said tool, and to cause said tool to follow said contoured surface, a tool-holding and tracer-deflecting mechanism for transmitting deflections of said tool produced by its contact with said contoured surface to said tracer valve and means maintaining said tool in contact with said surface with a substantially constant predetermined pressure.

2. A machine according to claim '1 including means for varying independently the speed at which the Workpiece is moved and means for controlling the speed at which the abradi-ng tool is traversed, whereby the relative movement between the tool and the workpiece takes place at a sutficient speed to ensure a high surface finish.

3. A machine according to claim 2, wherein said means for varying the speed of said workpiece and the means for controlling the speed of the tool are each operatively connected to driving means and a hydraulic transmission therefor operated by oil hydraulic pressure supplied from a single source, in which the total volume of oil supplied to said source is divided between each of said two driving means in predetermined proportion.

4. A machine according to claim 3 wherein said tool holding and tracer deflecting mechanism is actuated by upward and sideways movement of said abrading tool, and in which said abrad'ing tool projects down from said mechanism.

5. A machine according to claim 4, wherein said tool holder of said tracer deflecting mechanism pivoted for vertical movement and includes means for securing a tool therein to one side of said pivotal point, including means for guiding said holder for free vertical movement to resist movement of said holder in the other direction by the action of the moving workpiece on said tool.

6. A machine according to claim 5 wherein said means for exerting a predetermined pressure of said tool against the workpiece is adjustable within limits whichavoid restricting the accuracy of the reaction of the tracer valve.

7. A machine according to claim 6 wherein said tool holding and tracer deflecting mechanism is mounted on a head for vertical reciprocation relative to said substantially horizontally movable workpiece and is provided with means for angular adjustment relative to said head in a substantially vertical plane to enable the tool to be presented to the workpiece surface at a predetermined angle.

8. A machine according to claim 7 wherein said tool holding and tracer deflecting mechanism is mounted on a tracer controlled tool slide which is in turn mounted 1 References Cited in the file of this patent UNITED STATES PATENTS 2,354,347 Peets July 25, 1944 2,391,983 Kutzler Jan. 1, 1946 2,887,827

Conte et a1 May 26, 1959

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