US2558300A - Apparatus for finishing surfaces - Google Patents

Description

June 26, 1951 w. l. KNAPP APPARATUS FOR FINISHING SURFACES 5 Sheets-Sheet 1 Filed March 18, 1946 INVENTOR WALTER I. KNAPP ATTORN EYS my a June 26, 1951 W. l. KNAPP APPARATUS FOR FINISHING SURFAC 5 Sheets-Sheet 2 Filed March 18, 1946 FTMZnu/n' ATTORNEYS INVENTOR WALTER I. KNAPP 9y J June 26, 1951 W. l. KNAPP APPARATUS FOR FINISHING SURFACES Filed March 18, 1946 5 Sheets-Sheet 5 FIG.3

INVENTOR WALTER I. KNAPP ATTORNEYS INVENI'OR WALTER I. KNAPP ATTORNEYS 5 Sheets-Sheet 4 W I KNAPP APPARATUS FOR FINISHING SURFACES June 26, 1951 Filed March June 26, 1951 w. l. KNAPP 2,558,300

APPARATUS FOR FINISHING SURFACES Filed March 18, 1946 5 Sheets-Sheet 5 INVENTOR WALTER I KNAPP ATTORNEYS .skillets.

Patented June 26, 1951 UNITED APPARATUS FOR FINISHING SURFACES Walter I. Knapp, Detroit, Mich., assignor to Frederic B. Stevens, 1110., Detroit, Mich., a cor:

poration of Michigan Application March 18, 1946, Serial No. 655,306

7 .Claims. 1

This invention relates to apparatus for finishins utensils or vessels such as pots, pans and More particularly, this invention refers to an automatic machine for finishing the surfaces of cast, draw-n or spun utensils such as aluminum, copper or iron pans or skillets.

In the manufacturing of utensils a final .step is that of finishing the surface. This finish is usually obtained by spinning the utensil in a chuck and manualh abrading the surface with .a piece .of emery cloth or similar flexible cutting medium. In order to obtain the uniform and neat appearing results required, considerable skill must be employed in manipulating the abra sive member. In addition, the manual processing of the utensils is slow and the results at best are variable.

The object of the present invention is to pro vide a machine for mechanically finishing the insides Qf utensils and to obtain a result equal or better than is possible by manual means.

Another object is to provide such a machine which will be fully automatic.

Still another object is to provide an automatic machine for applying the final finish to the insides of utensils which includes a turret for holding the workpieces.

Still another object is to provide a machine according to the foregoing objects which is adjustable for different types and sizes of utensils.

Another object is to provide an apparatus for finishing the insides of utensils by abrading such that an improved product results and such that the rate of production is substantially increased.

It is also an object to provide, in connection with a machine according to the foregoing objects, safety limits by means of which the machine is halted suddenly in case of breakage, misadjustment orimproper operation.

These and other objects and advantages will become more apparent upon reference to the following description and the accompanying drawings in which:

Figure 1 is a plan view of a machine constructed according to this invention;

Figure 2 is a side View of the machine looking in the direction of the arrow 2 on Figure 1 Figure 3 is a section taken substantially along the line 3-3 of Figure 2;

Figure 4 is a view taken substantially along the line 4-4 of Figure 3 showing one of the :adi-ustments of the machine;

Figure 5 is :an enlarged view of the low-er end of the abrading arm in operative position;

Figure 6 is a section on the line 6-6 of Figure 5 showing one of the safety limits;

Figure -7 is a view looking substantially in the direction of the arrows 1---] on Figure 5;

Figure 8 is a section taken on the line 8-8 of Figure 5 showing the contour of the shoe at the end of the abrading arm;

Figure 9 is a section taken substantially along the line 9--9 of Figure 2 and shows the connections to the vacuum chuck in the turret;

Figures 10, 11 and 12 are fragmentary views showing the abrading arm and the actuating mechanism therefor in different operative positions during a cycle; and

Figure '13 is a wiring diagram for controlling the actuation of the abrading arm and theturret indexing motors.

General arrangement form of a flexible tape such as emery cloth and of a texture of from number to 100. When tape is used as the .abrading medium, a mechanism is provided for Shifting the tape a pred,e termined amount for each cycle so that a fresh abrading surface is presented to each utensil.

For actuating the abrading arm there is provided cam and linkage mechanisms which are driven in rotation by .a suitable motor means.

The cams and linkage drive the abrading arm so that the tip thereof follows the surface of the utensil being finished and the cam may b so shaped and the links so proportioned that the contour of any utensil may be followed'with great exactness.

A uniform pressure on the utensil is obtained by suitable yielding means which continuously urge the abrading tip of the abrad-ing arm into engagement with the Surface of the utensil.

Suitable means such as limit switches are located on the abrading arm so that improper operation of the machine, breakage :of the abrasive tape, or maladjustment of the machine, will immediately bring the machine to a halt, and :main- 3 tain it in a halted position until the trouble has been cleared.

In addition to the cam and linkage which may be replaced to vary the path through which the abrading tip passes, the machine includes means for raising and lowering the abrading mechanism as a unit, for moving it toward or away from the working station as a unit, or for bodily tilting the abrading mechanism.

Structural arrangement 7 Referring to the drawings and particularly to Figures 1 through 5, a machine according to this invention comprises a bed. II which adjustably supports a foot member I2 having, in turn, adjustably connected therewith the column I4.

The column It carries a table It towhich is pivoted, as at IS, a plate 23. In Figures 3 and 4 it will be noted that the table I6 is vertically adjustable on the column It by the rack 22 on the latter and the gear 2 carried by the former. The ,gear 24 is connected through the shaft 26, the self-locking worm mechanism 36 and the shaft 28 with a manual adjusting means at 32 which is operable to raise and lower the table It on the column M. The plate 28 is abutted by a screw 34 which passes through the table It and which is selectively operable to tilt the plate about its pivot I8 to any desired'degree of angularity.

The plate 23 has secured thereto the upstanding plate 36 upon which is carried the abrading mechanism generally indicated at 33. The abrading mechanism consists of an arm 46) which is slidable through a bearing block G2, which has at its lower end the abrading tip generally indicated at 44 and which is pivoted at its upper end at 46 to an arm 38. The arm 48 is pivoted between its ends as at 59 to the plate 36 and has a pivot 52 at its other end.

Pivoted to the arm as at 52 is another arm or link 54 which has a slot 56 therein which slides over a shaft 58 extending through the plate 36. Optionally the shaft 58 may have a roller or other suitable journalling means whereby the reciprocation of the link 54 relative thereto is facilitated.

The shaft 58 has connected therewith a cam 66 which has a cam track 62 formed into the face 7 thereof. The cam track 62 receives a roller or follower 64 which is secured to the arm 54. As

the cam rotates the arm 5:3 is reciprocated and has its end pivotally connected as at 68 with a lug outstanding from the bearing block 62. The several links may comprise a plurality of points 'for receiving the several pivots and the cam 50 may be replaced by another with a modified cam track for the purpose of varying the path through which the arm 40 passes. The particular arrangement shown in the drawings is for th pur pose of finishing the inside of a pan having a flat bottom and vertical side walls.

For driving the cam 68 in rotation, the shaft 58 is connected through the reduction gearing 59 with the output shaft 6| of a speed reducing transmission 63. The input shaft of the transmission 63 is connected to be driven by the electric motor 65. The motor and speed reducer are mounted on the plate 2!! in any suitable manner.

The utensil to be finished is indicated at In in Figures 1, 2, and 5 and will be seen to be supported in a chuck 12 which has a plurality of passages I4 and ports I6 therein. The passag 14 lead to a central passage I3 which passes vertically downwardly through the spindle 80 of the chuck to a plurality of substantially radial passageways which terminate in a circumferential groove about the said spindle. This groove is indicated at 82 and is in communication with a passage 84 in the turret plate 86 which supports the several chucks.

The turret plate 86 is carried on a central column 88 and is journalled in the upstanding portion 90 of the machine bed ID. For clamping the utensil in the chuck at the working station, there is provided a passage 92 in the portion 90 which is connected at one end with a vacuum conduit 94 and, at the other end, with a recess 96 which registers with the passage 8 when the turret brings the chuck into working position. The turret may be indexed by any suitable means but it is preferred to employ the Geneva mechanism consisting of the slotted plate 98' which is engaged by the rotary plate IQ!) having the indexing pinIIlZ. The plate in may be driven by any suitable means but, for the purposes of illustration, the motive power is shown in the drawings as comprising an electric motor I54.

The slotted plate 98 and the plate IOEl carrying the pin I82 operate in the manner of 'a regular Geneva mechanism, the pin it! engaging one of the slots of the plate 98 as the plate I00 rotates and indexing the plate 98 through 90 degrees to bring another workpiece into the work station. The raised part in the center of the plate H30 acts as a key to retain the plate 98 in its indexed position. It will be understood that the plate I00 could be operated continuously or intermittently, as desired, depending on the rapidity with which it is wished to index the turret 86.

For rotating the chuck 12 which is in working position, the spindle 8|! thereof is coupled with the drive shaft of a motor I04 which is carried on a plate I08 attached to the turret plate 86. The motor I04 is adapted for energization when the chuck to which it is attached is moved into working position by means of the brush mechanism and slip ring indicated at I98.

Returning to the abrading arm, and particularly to the abrading tip Mi, this portion of the mechanism is more clearly seen in Figure 5. The arm 4!] comprises a rectangular or cylindrical tube having connected therewith a plate III]. Adjustably mounted within the plate I H] is a rod I I2 that extends downwardly and has a head H4 thereon. Slidably mounted in the end of the arm 4%] is a framework H6 which carries the abrading tip mechanism which has been indicated generally at 44. The said mechanism is urged downwardly by a spring H8 which bears between a plate I2!) secured to the framework I I6 and a plate I22 which is adjustably supported in the arm M) as by the screws and wing nuts I24 which extend through the slots I26 in the arm The framework H6 extends downwardly from the arm 40 and carries a channel portion I28 which has journaled in the lowermost end thereof a roller I30 of some suitably resilient material such as felt. The roller I30 is preferably curved to have a somewhat greater curvature than the utensil being finished as is indicated in Figure 8.

Passing around the roller I3!) is a flexible tape I32 which is coated with emery or a similar abrasive and preferably of about the texture of No. to No. 100 emery. The tape I32 is paid off from a reel I34 carried between a pair of arms which extend laterally from the framework I I6. A'tension spring I36 connected between the reel I34 and the supporting bracket therefor continuously urges the said reel in its taking up direction with a substantially constant torque, whereby a substantially predetermined tension is maintained on the tape I32. After the tape passes around the roller I33, it is attached toa takeup reel 138 that is also carried in a pair of arms extending from the framework H6. The reel 138 has connected therewith a ratchet wheel M0 which is engaged by a spring pressed pawl M2. A second pawl I44 is urged away from the said wheel by a spring I46. The tape is guided between the reels by the channel guards I 33 and I35 and passes over a roller I31 immediately before passing to the takeup reel.

As will become apparent hereinafter when the arm 16 is moved upwardly and out of the utensil 16, the upper end of the pawl I44 strokes the arm I4 8 carried on the bearing block 42 and actuates the said pawl to index the reel I38 to take up the predetermined amount of the tape I32. This automatically provides a fresh abrasive surface to be presented to the next utensil to be finished.

The spring 8 urges the abrading tip against "the bottom of the utensil with a predetermined thrust and, when the arm 6!! is moved to present the abrad'ing tip to the side of the utensil, the

hinge I56 and spring I52provide tensioningmeans for urging the abrading tip laterally against the side of the utensil with a substantially equal thrust.

In connection with Figure 2, Figures 10, '11 and I12, illustrate the cam, links and abrading tip in several of its operative positions during a work cycle. Figure 2, the abrading tip is resting .in the center of the bottom of the utensil. In Figure 10, the cam 66 has rotated about 60 and the abrading tip has reached the corner of the utensil. It will be noted that the roller I30 has a radius not greater, and preferably smaller, than the radius of theflllet in the corner of the utensil. In Figure 11, the cam has rotated until the abrading tip has reached the upper edge of the utensil side wall, and in Figure 12, the cam is turned to bring the abrading tip substantially vertically above the starting position indicated in Figure 2.

For actuating the cam driving motor 65 and the turret indexing motor I54, there is provided the electrical circuit illustrated in Figure 13. In this figure, the power lines are indicated at :LI

and L2 and therebetween are connected the sevit will be seen to comprise mating contacts carl P 'ried on the framework H6. The framework is divided between the contacts and there is a hinge 162 which permits the contacts to open when the lower portion of the framework H6 .is pivoted relative to the upper portion. The lower portion of the framework is yieldably retained in position by the spring and detent mechanism indicated at I64.

The switch I58 is a sensitive limit switch and is carried in the U-shaped member I28. The

6 switch I58 is normally held closed by its actnat .ing roller I66 which is engaged by the tape I32. When the tape breaks, runs off the payoff reel, or loses tension for any other reason, the switch I58 opens to halt the machine.

The switch I60 is a manually operated on and off switch and is preferably carried on the table I6 or in any'other position convenient to the machine operator.

The side of the switch I58 opposite the line LI is connected with a line I68 which, in turn, is connected through the limit switch LSI and the contactor coil B with the line L2. The limit switch .LS'I is carried on the machine bed and is actuated into closed position by the cams I10 carried on the turret plate 86. The contactor coil B has the normally open blade BI which is in series with the cam motor 65 between the lines I68 and L2. The blade BI is bypassed by the normally closed blade AI of the contactor A which is in series between the lines L2 and I68 with the normally open limit switch LS3.

The switch LS3 is preferably carried on the bearing block 42 and is adapted for being actuated into closed position by an adjustable abutment I12 connected with the arm 40. When the arm 40 is moved to its Figure 12 position, the switch LS3 is actuated to its closed position to energize the contactor coil A and to open the blade AI thereof.

Connected between the lines I68 and L2 is a contactor coil C in series with a selector switch I14, and a normally open limit switch LS2. The limit switch LS2 is bypassed by the push button station I16 and a holding circuit consisting of the normally open blade C2 and the normally closed limit switch LS4. The limit switch LS4 is carried on the machine bed and is actuated into opened position temporarily by the cams I10 as the turret rotates. The limit switch LS2 is preferably supported on the bearing block 42 and is temporarily actuated into closed position as the arm '40 moves upwardly and toward its Figure 12 position. The selector switch I16 may be closed as indicated for full automatic operation of the machine and opened for semi-automatic to initiate a new cycle. When the switch I14 is opened, the push button I16 must be closed to inaugurate each new cycle.

The contactor coil 0 has the normally open blade .CI in series with the turret indexing motor I54 and, when the coil C is energized, the index motor operates to rotate the turret. The blade CI is bypassed by the normally closed blade B2 of the coil B.

In order quickly to halt the operation 01" the machine in the event that either of the emer gency limit switches or the hand switch I56 is opened, the motors may be provided with a magnetic brak construction, one of which is shown in association with cam driving motor 65. The brake construction. consists of a drum I18carried on the motor shaft and a pair of shoes I86 surrounding the drum and urged away from the said drum by a spring I 82. A solenoid and armature indicated at I 84 is adapted, when energized, to actuate the brake mechanism and there by suddenly to halt the rotation of the drive motor. For actuating the solenoid I84, there is provided in a series therewith the normallyclosed blade D3 of the contactcr coil D. The solenoid I84 and the blade D! are connected between the lines LI and L2 while the coil D is connected between the lines L2 and I58. When any of the switches I56, 158 or 166 are opened, the coil ,D

Operation In operation, a pan-shaped workpiece, such as a kitchen utensil, is placed in the turret and indexed into position under the abrading station. When the turret reaches working position, the switch LSI is actuated to energize the coil B thereby to close the blades Bl thereof and to open the blades B2 thereof. Opening of the blades B2 deenergizes the turret motor I54 and closing of the blades Bl energizes the cam motor 65.

Energization of the cam'motor 65 drives the abrading arm through its path to finish the "interior of the utensil Hi, the said utensil being driven in rotation by its supporting chuck 12. When the abrading arm has finished its working stroke and is approaching its Figure 12 position, it actuates the limit switch LS2 into closed position. Closing of LS2, if switch H4 is closed, energizes the coil C which is held by the holding circuit including the blade C2 and the switch LS4.

Energization of C closes the blade Cl and ener gizes the turret indexing motor. The "turret therefore commences its indexing movement. The abrading arm 59 continues its upward movement until it passes the limit switch LS2 and strikes the limit switch LS3. Closure of the limit switch LS3 energizes the contactor coil A to open 7 the blade A2 thereof thereby to deenergize the cam motor 65. At this time, the turret has indexed to the position where the cam I70 permits the limit switch LSI to open so that the coil B is deenergized and the blade Bl thereof is opened and blade B2 thereof is closed.

The cam motor thus remains deenergized. As the indexing movement of the turret progresses, one of the cams ll!) opens t -e limit switch LS4 and deenergizes the coil C. Deenergization of C opens the blade Cl thereof but the indexing motor Hill continues to operate because of the blade B2 which is closed.

When the turret has indexed to the point where one of the cams Iii? closes the limit switch LSI, the coil B is energized and a new cycle is commenced.

If the switch H4 were opened, the abrading arm. would gothrough one cycle and halt in its upper position and a new cycle would be instituted by closing the push button I16. 7

If, at any time, the emergency switch I56 or the limit switch I58 or the hand switch I60 is opened, both of the drive motors are immediately deenergized While the brake or brakes associated with one or both thereof are energized to bring the entire mechanism to a sudden stop.

It will be understood while only one form of utensil has been illustrated in the accompanying drawings, the abrading mechanism is capable of adjustment to perform a finishing operation on substantially any size or shape pan, skillet or the like.

In any case, the finish on the utensil or vessel is uniform, precise, neat appearing and quickly accomplished so that there is a material saving in labor, and an improvement in the quality and appearance of the finished product.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. In an apparatus for finishing abrading one of the inner and outer surfaces of a pan-shaped workpiece, means for supporting and rotating said workpiece, a movable arm, an abrading member yieldably carried on the end of said arm to be moved thereby over said surface from the center of rotation of said workpiece outwardly, a joint in said arm, switch means responsive to a predetermined thrust on said abrading member transverse to its direction of movement across said surface for breaking said joint thereby permitting said abrading member to deflect away from the surface being finished, motor means energizable to actuate said arm, and switch means responsive to the deflection of said abrading member for de-energizing said motor means and for halting movement of said arm.

2. In an apparatus for finishing one of the inner and outer surfaces of rotating pan-shaped workpieces, means for supporting and rotating said workpiece, a movable arm; electric motor means energizable to actuate said arm, a finishing member yieldably carried on the end of said arm, a joint in said arm adapted for being broken in response to a predetermined thrust on said finish- 'il'ig member lateral to its direction of movement,

electrical contacts in circuit with said motor means, and means carried on said arm and adapted to be actuated by the breaking of said joint to actuate said contacts to de-energize said motor means.

3. In combination, in a machine for abrading a surface on a workpiece, means for supporting and rotating said workpiece on an axis passing through the center of said surface, an arm, abrading means carried on the said arm comprising a supply of abrasive tape extending over the end of the arm, power means to actuate said arm to carry said abrading means in a closed path a part of which is along and in engagement with the said surface and the other part of which is idle travel, means operable durin the idle travel of said arm to feed said tape, and switch means responsive to the breakage of said tape to halt said power means.

4. In combination, in a machine for abrading a surface on a workpiece, means for supporting and rotating said workpiece on the axis of symmetry of the surface to be finished, an arm; abrading means carried on the said arm comprising a supply of abrasive tape extending over the end of the arm, takeup means to tension said tape,

power means energizable to actuate said arm to carry said abrading means in a closed path a portion of which is along and in engagement with surface being finished and the remainder of which is idle return travel along a line spaced from the said surface, means to feed a predetermined amount of said tape during the idle travel of said arm, and switch means operable automatically to de-energize said power means when said tape loses tension.

5. In a machine for finish abrading a surface of a workpiece, means for supporting and rotating a workpiece having a bottom and peripheral wall about the axis of symmetry of the said'surface, an arm, a roller carried on the end of said arm adjacent the surface to be finished, and abrasive coated ribbon passing over said roller for abrading the said surface, a pay-01f reel and a takeup reel for said ribbon carried on said arm and one thereof being spring urged to tension said ribbon and the other thereof being intermittently actuated to feed a predetermined amount of ribbon over said roller, power means energizable to actuate said arm to carry said roller over the surface being finished from the initial contact at the said axis of the workpiece outwardly to the peripheral wall and along the peripheral wall, and switch means responsive to loss of tension in said ribbon for autorntically de-energizing said power means thus to bring said machine to a halt.

6. In a machine for finish abrading the inner surface of a rotating pan-shaped workpiece, means to support and rotate said workpiece, a movable member adapted to have its end positioned against and moved across said surface, an abrading means carried by said member to be ,moved across said surface thereby, said abrading means comprising a resilient roller of a curvature in any plane greater than the curvature of said inner surface in the same plane, a flexible abrading ribbon passing over said roller, and ratchet wheel means operable automatically to feed said ribbon a predetermined amount after each movement across said surface to present a new abrading surface to each workpiece.

7. In a machine for finish abrading the inner surface of a rotating pan-shaped workpiece, a turret, a plurality of rotatable work supporting chucks on said turret, means for indexing said turret to bring said chucks consecutively into a work station, means operable to clamp workpieces in said chucks when in said work station and for rotating said chucks, abrading mechanism including a movable arm adjacent said work station adapted to contact the inner surface ofthe workpiece at the axis of rotation, an abrading end part on said arm, power means to actuate said arm to move said end part in a closed path 10 of which a part is the same shape as said inner surface from the initial contact point at the axis of rotation of the workpiece outwardly, a column adjustably supported adjacent said turret, and means adjustably supporting said abrading mechanism on said column.

WALTER I. KNAPP,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 167,858 Sperry Sept. 21, 1875 189,505 Scully Apr. 10, 1877 369,326 Dufi Sept. 6, 1887 446,170 Sperry Feb. 10, 1891 612,239 Grohmann et a1. Oct. 11, 1898 612,240 Harper et al Oct. 11, 1898 1,089,456 Beam Mar. 10, 1914 1,140,424 Webb May 25, 1915 1,271,837 Bille July 9, 1918 1,325,789 Johnson Dec. 23, 1919 1,860,905 Schipper May 31, 1932 1,888,710 Arter et al Nov. 22, 1932 1,927,476 Walker et a1. Sept. 19, 1933 1,974,806 Curtis et a1. Sept. 25, 1934 2,137,250 Schultze Nov. 22, 1938 2,145,310 Lewis et a1 Jan. 31, 1939 2,338,644 Illmer et al. Jan. 4, 1944 2,386,850 Gaudreau et al. Oct. 16, 1945 2,401,670 Spetz June 4, 1946 2,470,221 Mott May 17, 1949 FOREIGN PATENTS Number Country Date 16,132 Great Britain 1915

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