US2386649A - Automatic multiple buffing machine - Google Patents

Description

Oct. 9, 1945.

P. J. BELCOURT AUTOMATIC MULTIPLE BUFFING MACHINE 7 Filed Jul 20, 1943 s Sheets-Sheet 1 i i i 1 1 lflr I: I

INVENTOR PAUL J. BELCOURT ATTORNEY Oct. 9, 1945. BELCQURT 2,386,649

AUTOMATIC MULTIPL'IE BUFFING MACHINE Filed July 20, 1943 8 Sheets-Sheet 2 INVENTOR PAUL J. BELCOURT ATTORNEY Oct. 9, 1945.

P. J. BELCOUI'RT AUTOMATIC MULTIPLE BUEFING MACHINE Filed July 20, 1943 8 Shams-Sheet 3 INVENT OR PAUL J. BELCOURT ATTORNEY Oct. 9, 1945. p, J BELCOURT 2,386,649

AUTOMATIC MULTIPLE BUFFING MACHINE Filed July 20, 1943 8 Sheets-Sheet 4 if 1 B- HI! I! INVENTOR PAUL J. BELCOURT ATTORNEY Oct. 9, 1945. P. J. BELCOURT AUTOMATIC MULTIPLE BUFFING MACHINE 8 Sheets-Sheet 5 Filed July 20, 1945 T m R mm NL R EE 0 w w 9 i Aw P Oct. 9, 1945.

P. J. B ELCOURT AUTOMATIC MULTIPLE BUFFING MACHINE Filed July 20, 1943 8 Sheets-Sheet 6 INVENTOR PAUL J. BELCOURT ATTORNEY Oct. 9, 1945. P BEL'CQURT 2,386,649

AUTOMATIC MULTIPLE BUFFING MACHINE Filed July 20, 1943 8 Sheets-Sheet 7 Til gin- 4 .INVENTOR PAUL J. BELCOURT ATTORNEY Patented Oct. 9, 1945 UNITED STATES EPATENT OFFICE AUTOMATIC MULTIPLE BUFFING MACHINE Paul J. Belcourt, Meriden, Conn. Application July 20, 1943, Serial No. 495,473

13 Claims.

This invention relates to abrading, and more particularly to an automatic multiple unit buffing machine in which all of the units of said machine are located in a single large ventilated dust exhaust housing and are controlled from a single panel board located in a portion of the machine fram projecting outside of said housing in full View and within easy .reach of the operator.

One object of the present invention is to provide a machine of the above nature in which the buffing wheels of all of said units are automatically controlledindividually by switch and timer apparatus mounted on the panel board.

A further object is to provide amachine of the above nature in which the buffing wheel of each unit will be intermittently moved against the work being buffed by the operation of an individual auxiliary electric motor, so as to maintain said wheel automatically in contact with said work at all times.

A further object is to provide a machine of the above nature in which the downward movement of the bufiing wheel in each unit will be interrupted by means of a current relay arranged in circuit with the bufiing wheel motor of said unit, which relay will be operated whenever the current in said circuit has increased to a predetermined amperage caused by the pressure of the bufling wheel against the work.

A further object is to provide a machine of the above nature in which the motion of the buiiing wheel against the work in each unit will be repeated automatically at regular intervals under the control of motor-driven timing apparatus located on the common panel board.

A further object is to provide a machine of the above nature in which apparatus is provided for each unit for automatically stopping the rotation and downward motion of the billing wheel when it has been worn down sufficiently to require replacement, and to provide a signal at such a time indicating to the operator when it is necessary for him to enter the housing for making such a replacement.

Afurther object is to provide a machine-of the above nature in which the buffing wheel of each unit will be mounted universally and for vertical adjustment to permit the buifing wheel to engage the work in any desired horizontal, vertical, or angular position.

A further object is to provide a machine of the above nature in which the separate .buffing Wheel supports may be quickly attached to and detached from the central frame of the machine.

A still further object is to provide a machine of the above nature which will be relatively simple in construction, inexpensive to manufacture, easy to adjust, accurately controlled, compact, labor-saving, and very efficient and durable in use.

With these and other objects in view there have been illustrated on the accompanying drawings two forms in which the invention may conveniently be embodied in practice.

In the drawings:

Fig. 1 represents a side elevation of one .of the buffing units embodying the present invention, with certain parts broken away for clearness, looking in the direction of the arrow l of Fig. 4, and showing in dotted lines a raised adjusted position of the buffing wheel carriage and two adjusted angular positions of the buffing wheel.

Fig. 2 is a top plan view of the same, shown partly broken away, and partly in section.

Fig. 3 is a cross-sectional view of the same, taken along the line 33 of Fig. 1, looking downwardly in the direction of the'arrows.

Fig. 4. is a rear view of the same, looking in the direction of the arrow 4 .of Fig. 1, and showing in dotted lines an adjusted angular position of the buffing wheel carriage.

Fig. .5 is a side elevation of the same, looking from the direction of the arrow 5 of Fig. 4.

Fig. 6 is a horizontal sectional view taken through the exhaust housing, partly broken away, looking downwardly along the line 66 of Fig. 1.0, and showing the central machine frame, the four attached bufling units and the control panel board located outside the housing.

Fig. 7 is a sectional view of the same, taken along the line 1-1 of Fig. 10, looking downwardly and illustrating the machine frame and the location of the motor which drives the work table.

Fig. 8 is a side view of one of the buffing units, showing in dotted lines an adjusted angular position of the bufiing wheel carriage.

Fig. 9 is a view similar to Fig. .8, showing a modified form of mechanism for driving the buffing wheel, in which a multiple belt is employed instead of a direct motor drive.

Fig. 10 is a front view of the dust exhaust housing enclosing the automatic multiple bufiing machine, as it appears from in front of the operators position.

Fig. 11 is an electrical diagram of the wiring circuits of one unit of the multiple bufling machine, and including the associated electrical apparatus for automatically starting and stopping the compound applicator whenever the buffing Wheel motor is turned on or off respectively.

Electrical Apparatus Referring now to the drawings, in which like reference numerals denote corresponding parts throughout the several views, the numeral I indicates a master stop push-button switch (see Fig. 11), said switch being adapted to be held closed by a spring Ia and by the manual opening of which, the bufiing wheels BW and associated apparatus of all units of the machine may be simultaneously stopped whenever desired.

The numeral 2 indicates a plurality of conductors (four in this instance) leading to the individual wheel motor switches of the various units of the multiple machine, which machine is adapted to receive control power from a pair of line wires LI and L2 which are supplied from any suitable A. C. source.

The numeral 3 indicates generally a unitary switch which controls the wheel motor I, the

motor of the timer I4, and the applicator motor I9 of one individual unit of the machine.

The switch 3 consists of four pairs of stationary contacts 30., 3a; 3b, 3b; 3c, 30; 3d, 3d, and four movable contacts 3e, 3 3g, 3h, adapted to bridge said stationary contacts 3a, 3a; 3b, 3b; 3c, 30; 3d, 311, respectively. These four movable contacts are rigidly connected together and insulated from each other by a common carrier rod 32' (shown in dotted lines in Fig. 11)

The carrier rod has a rigid offset angular section 37 provided with an electrical interlock movable contact 5 which is adapted to bridge a pair of stationary contacts 5a, 52) located on the frame of the switch 3 to keep all the contacts of switch 3 closed during the bufiing operation.

The switch 3 may be opened at any desired time by the manual actuation of the stop section of the push-button B, and automatically opened by the operation of the mechanical limit switch I I, as will be described later.

The conductor 37c connects the left stationary contact 3a to .the line wire L2. The right hand stationary contact 3a is connected by a conductor 3L to the applicator circuit I9a, and by a conductor 3m to the motor circuit of the timer H5.

The conductors 3n, 30, and 3p indicate three 3-phase conductors connecting the right hand stationary contacts 3b, 3c, 3d to the motor '5 of the bufiing wheel BW.

The carrier rod 32 has an extension 3g located within a solenoid coil 3r connected on each side to a pair of safety overload relays 6 which are adapted to open the switch 3 in case an accidental excessive current should pass through the wheel motor I.

The control circuit for the switch 3 includes the lower conductor 2, the overload relays 6, the coil M, the contacts 5a, and 5b, and the three conductors 5c, 5d, 5c. The pair of conductors to and 5d are connected to the stationary contacts 56, 5) of the start side of the push button 8, which contacts 5e, 5 are bridged by a movable contact 5g normally held in open position by a spring 5h.

The contact 5 is connected by a conductor 8a to a stationary contact 8b at the stop side of the push-button 8. A movable contact 80, normally held closed by a spring 8d, connects the contact 8b to another stationary contact 8e, which in turn is connected by a conductor 3f to a normally-closed jog push button switch 9 located in the control circuit of the switch 3. This switch 9 includes a movable Contact By normally held by a spring 8h against a pair of fixed contacts 9a, 9b, which are adapted when the pushbutton is depressed to engage fixed contacts 90, M. This construction permits the buffing wheel to be operated momentarily and independently from the inside of the exhaust housing for test purposes. It will be understood that the wheel BW will be operated only so long as the switch 9 is manually held on.

In order to control the length of the time interval between the inward motions of the bufling wheel BW under the operation of the auxiliary two-speed reversible motor I5, to be described later, provision is made of an adjustable motor driven timer I i of the continuously operating repeating cycle type.

The timer It includes a rotating cam I50, mounted on a shaft I41) and driven continuously by a motor (not shown) which receives power from the conductors 3m and I40, the latter being connected to the line wire LI. The rotation of the cam I411 will cause a movable contact Hid to be momentarily bridged across a pair of fixed contacts I ie and I4 said movable contact being normally held open by a spring I lg.

The closing of the timer switch by the action of the cam I ie, will cause a down switch 22 to be closed automatically forcontrolling the auxiliary motor I5.

The down switch 22, which is similar to the wheel motor switch 3, previously described, consists of five pairs of stationary contacts 82a, and 82b, 22a, and 22b, 22 and 22d, 22c and 22 22g and 22h, and five movable contacts 82, 87, 83, 89, and 99, respectively, which movable con tacts are rigidly connected together and insulated from each other by a common carrier rod 9I (shown in dotted lines). The carrier rOd GM has a rigid offset angular extension S2 provided with an electrical interlock movable contact 93 which is adapted to bridge a pair of stationary contacts 94, 95 located on the frame of the switch 22 and which serve to keepthe upper movable contact 82 open and the four movable contacts 81, 88, 89, 98 closed during the operation of the auxiliary motor.

The conductor 96 connects the stationary contact 22a to the line wire L2 and the contact 22b is connected by a conductor 97 to the pilot lamp I3 which in turn is joined by a conductor S8 to the line wire LI.

The conductors 99, I00, and I0! indicate three S-phase conductors which connect the stationary contacts 22d, 22), and 22h to the auxiliary motor 55 in such a manner as to drive the wheel head carriage toward the work W when the switch 22 is closed.

The carrier rod 9| has an extension I02 located within a solenoid coil 6a connected to a pair of overload relays I93, I04 which are adapted to open the switch 22 in case of an accidental overload of the auxiliary motor I5.

The numeral II} indicates a push-button switch movable contact normally held open by a spring I95 and adapted to be momentarily closed against a pair of fixed contacts Illfia, 35b by the manual operation of the push button of said switch I0 to permit the down or in switch 22 to be closed to operate the auxiliary motor I5 independently of the timer Id. This switch it! is used immediately after the installation of a new wheel. The contact I056; is connected with contact Si by a conductor H350, while the contact I051) is joined to the line wire L1 by a conductor I Md.

The numeral I2 indicates a normally on jog push button switch located within the exhaust housing, and includes a movablecontact I06 normally held closed by a spring I ll! against .a pair of fixed contacts I08, I09.

When the contact L06 is pushed downwardly it will engage a pair of fixed contacts Hi), .I I I and cause the auxiliary motor I to run in the down .or in direction, as long as said contact 1061s held down. This will permit the auxiliary motor I5 to drive the buffing wheel carriage BW toward the work W independently of the timer I4 as long as the push button I 2 is held on.

The current relay 4 serves to stop the auxiliary motor I5 whenever the current in the circuit of the wheel motor I has attained a'predetermined value, in response to the increase in pressure of the bufiing wheel BW against the work, as the wheel is advanced toward said work.

The relay 4 includes a coil I I2 which loosely surrounds an iron rod I I3 having a movable contact I I4 connected thereto. normally held closed against a pair of stationary contacts H5, H6 by a coiled spring Ill.

The coil H2 is connected to the conductor 30 by a conductor I I8 at the terminal 85. The other end of the coil I I2 is connected at the terminal 8% to a conductor H9 leading to the motor 7.

The stationary contact H5 is connected to the stationary contact; |4f by a conductor I20, while the stationary contact H5 is joined by a conductor .I2I to the fixed contact I68 of the jog switch I2.

Provision is also made of a :pair of pilot .lamps I3 and I6, which automatically indicate when the auxiliary motor I5 has started to move downwardly or upwardly, as the case may be.

Provision is also made of an up switch 23 for operating the auxiliary motor I5 in the reverse direction at a high speed in order to raise said bufiing wheel rapidly from the work when it is worn down to the hub, and thus minimizing the time required for changing buffing wheels.

The up switch 23 consists of four pairs of stationary contacts I22 and I23, I24 and I25, I26 and I21, I28 and I29 which cooperate with four movable contacts I30, -!.3I, I32, I33 respectively, said movable contacts being rigidly connected together and insulated from each other by a common carrier rod I 34, the lower end of which is located within a solenoid coil .65. The coil 6b is connected to a pair of safety overload relays I35, I36 which are adapted to open the up switch '23 in case of an accidental overload of the auxiliary motor I5.

The fixed contact I22 is connected'by a conductor I31 to the line wire L2 and "the fixed contact I23 is connected by a conductor I 38 to the pilot signal lamp I5 which in turn is joined to the line wire L1 by a conductor I39.

The numeral I I indicates 'a combination normally closed and a normally open non overlapping maintained'contact limit switch, '(see Figs. 2 and 11), which when tripped :by the limit lug II will stop the wheel motor I, the applicator motor I9, and the timer I4, and at the same time will reverse the auxiliary motor I5.

The limit switch II which is of the double pole double throw maintained contact type, as shown in Fig. 11, consists of two pairs of stationary contacts I46 and MI, I42 and I43 which :are adapted to be engaged by .a pair of movable contacts I44 and I45, respectively, the latter contacts being mounted on a common insulated carrier rod I46.

The fixed contact I42 is joined to a junction I41 at the overload relay I36 by a conductor I48.

The contact H4 is The left hand fixed contacts of the switches 3, 22 and 23 :are all supplied with A. C. from any suitable source of 3-phase power.

The numeral I'I indicates an up jog pushbutton located in the exhaust housing, for permitting the operator to produce an upward motion of the buifing wheel independently of the limit switch It A movable contact I59 is normally held in open position by a spring I62, and when momentarily closed engages a pair of fixed contacts I60, ISI.

The application of buffing compound to the buffing wheel .BW is controlled by means of a variable resistance I8 located in circuit with a compound applicator motor I9, and in operation, said resistance I8 is adapted to control the automatic successive feeding strokes of the block of compound to said applicator (not shown).

Provision is also made of a normally 'ofi limit switch 29, associated with the applicator, to light up a signal pilot lamp 2I, in circuit with said switch 20, when said switch closes to indicate that the compound cake is worn down and .requires renewal.

The applicator switch 20 has a movable contact I49 normally held open by a spring I56 and is adapted to engage a pair of fixed contacts I5I and I52.

Provision is also made of a jog push-button 24, located within the exhaust housing, for permitting each applicator to be operated independently of its associated buifing wheel control circuit. The push button 24 has a movable contact I53 normally held against a pair of fixed contacts I54 and I55 by a spring I55. When the button 24 is depressed, the contact I53 engages fixed contacts I57 and I58.

In order to permit the plunger N3 of the current relay -4 to reset quickly after each operation, provision is made of a movable normally on bridging contact 82 secured to the common holder rod SI of the movable contacts of the switch 22. The contact 82 engages a pair of stationary contacts 82a, 821), which are connected by conductors 8.3 and '84 to the points 85 and 86 of the current relay 4, as shown in Fig. '11. It will thus be seen that when the switch 22 opens, the contact 82 will bridge the contacts 82a and 82b causing the conductors 33 and 84 to be shunted across the coil of the current relay '4, thus destroying the magnetism thereof.

This will permit the movable contact I I4 of the relay 4 to drop or reset instantly and thus avoid hesitation or chattering of said contact I I4 with respect to the fixed contacts H5, H6.

No attempt has been made in the diagram of Fig. 11 to show the complete circuits, and only the essential details have been illustrated which should be sufiicient to enable a person skilled in the art to properly understand the operation of the invention.

Mechanism Each individual buffing machine unit comprises a support casing 25 having an adjustable top plate provided with four straight slots 21, 2". and 23, 28 which permit a sliding adjustment of said plate with respect to the center work table 73, to be described later, and which is housed within a central machine frame F. The plate 26 isadapted to be secured in adjusted position by means of two pairs of bolts 29., 29 and 35, .35 passing through said slots 2?, 2! and 23, 2.3 respectively.

Provision is also made of an angle bracket 31 located beneath the top plate 26, which bracket 3I is also provided in its upper horizontal section with a pair of arcuate slots 32, 32 for receiving a pair of bolts 33, 33 which serve to clamp said angle bracket 3| in adjusted angular position with respect to a vertical bolt 33a depending from the top plate 26.

In order to limit the downward movement of the buffing wheel post 43, to be described later, provision is made of an angular stop member 34 secured to the bottom of the bracket SL The vertical position of the buffing wheel carriage may be manually adjusted. whenever desired, by means of a pair of horizontal bearing journals 35 and 36 secured as by bolts (as shown in Figs. 1 to 4) to the vertical depending section 63a of the angle bracket 3|. A horizontal shaft 31 having a hand wheel 38 on one end thereof is mounted to rotate within said journals 35 and 36. The shaft 31 is provided with a ratchet wheel 39 adjacent the hand wheel 38, and said ratchet wheel is prevented from rearward rotation by means of a pawl 40 pivoted on the journal 35.

The shaft 3! is provided at its center portion with a pinion 4] which is' adapted to mesh with a vertical rack 42, secured as by bolts 42a, 52a, to the bottom part of the upstanding support post 43, which is preferably of thin rectangular crosssection. The post 43 passes upwardly through an arcuate slot 44 in the top plate 26, said slot permitting angular twisting of the support post within the limits of its adjustable motion.

After the support post 43 has been adjusted to the desired vertical position, it may be clamped tightly in such position by means of a pair of gib plates 45 and 46, and two pairs of bolts fill, El and 48, 48, the threaded ends of which are screwed into the vertical section 58a of the angle bracket Above the support casing 25, the post 53 is offset laterally by means of an upwardly inclined section 49 which is strengthened by a reinforcing rib 53, and is provided at its upper vertical end 53a with a vertical flange extending at right angles to said upper end Sta.

In order to provide for a universal angular adjustment of the buiflng heel BW with respect to the work W, provision is made of an angle plate 52 secured upon the upper flange 5| of the post 43, which plate is adapted to be swiveled in a vertical plane upon the flange 5i, and held in any desired adjusted angular position thereon by means of four bolts, 54, 55, 5s, 54, located in curved slots 53, 53, 53, 53 (as clearly shown in Figs. 2 and 4) .the swiveling taking place about a horizontal center bolt 54a.

As clearly shown in Fig. 5, the base 55 of the angle plate 52 serves as a rigid carrier for a head or carriage plate 56, which is adapted to be swiveled about a bolt 59, projecting from said base 55. The head plate 56 is adapted to be clamped in adjusted position upon said base 55 by means of four bolts, 58, 58, 58, 58, located in four arcuate slots 51, 57, 51, 51, formed in said plate 55. The wheel head plate 56 also carries a gib plate 62 to which it is connected by means of a pair of channel irons 65 and 6| (see Fig. 4) and said gib plate is provided with opposed bevelled edges 62a and 62b which fit within and guide a dovetailed movable slide plate 53, which carries the buffing wheel motor.

The bufiing wheel is adapted to be driven toward and away from the work by means of an elongated worm screw 64 connected at one end to a worm gear box 65 mounted on the auxiliary two-speed motor I5, and said worm screw 64 is adapted to rotate within a bearing 66 rigidly connected to the gib plate 62, and a nut 6'! rigidly secured to the slide plate 63. The limit switch I I is rigidly mounted on the slide plate 63 and in cooperation with a stop pin 69 and a pair of limit lugs I0 and II, which are attached to the gib plate 62, automatically controls the operation of the auxiliary two-speed reversible motor I 5 for rapidly moving the bufiing wheel away from the work when said wheel needs replacement, and stopping said wheel at the outer limit of its motion.

In order to index the work table 73, provision rality of work spindles I4 (one for each of the four bulfing units of the machine). Each of the spindles M is provided with a sprocket gear which is adapted to be engaged by a chain 16 at all of the five stations, except at the work changing position at the front of the casing 25, where the chain I6 is maintained out of engagement with the sprocket gear I5 'by an idle pinion 16a, so that the work chuck does not rotate at that point. The arm 13a is driven by an electric motor TM (see Fig. '7)

Provision is also made of a single common control panel board I7 located within the portion of the machine frame projecting outside the dust housing 79 in a position convenient to the operator for permitting him to adjust the various electrical apparatus on said panel board to control all the units of the multiple bufiing machine without leaving his operating position. The panel board H is protected by a pivoted door 78.

The exhaust dust housing I9 serves to prevent the escape of dust from the bufiing wheel operations into the room where the machine is located, and surrounds the machine frame F which encloses the multiple bufling machine. Dust is thereby excluded from the panel board 11. Access to the interior of the housing 12, for the purpose of changing buffing wheels, is permitted by means of a pair of side doors 8!] and SI.

Operation In the normal operation of the machine, the bufling wheel of each unit will be automatically controlled individually and independently of the other units by the electrical apparatus previously described herein.

In the cycle of operation of each bufiing wheel BW, when the push button 8 of its unit is pressed, the wheel motor switch 3 will start the motordriven timer I4 into operation, and at the same time will turn on the buffing wheel motor 1 and the applicator motor I3. At the end of the interval for which the .timer I4 is set, the relay switch 22 will be actuated, throwing on the auxiliary motor I5 at slow speed which will drive the bulfing wheel forwardly toward the work. This forward motion of the bufling wheel will continue until said wheel exerts a predetermined pressure against the work, which will cause an upsurge of current in the bufiing wheel motor circuit sufii cient to actuate the current relay 4, which will stop the slow downward motion of the auxiliary motor l5, until the timer I l again starts said auxiliary motor I5. This cycle will'continue repeatedly until the bufling wheel has been worn down to its hub (or has been reduced to a predetermined diameter). At this time, the limit switch II will be actuated by means of the stop lug lI thus stopping the buffing wheel motor I, the applicator motor I9, and the motor of the timer l4. At the same time, the down switch 22 will also be opened and the up switch 23 closed. The signal lamp l6 will also be lighted for visually indicating to the operator that a new bufiing wheel is needed, so that he may enter the exhaust dust housing through one of the doors 80, 8! for the purpose of installing it. The closing of the switch 23 wil1 reverse the auxiliary motor 15 which will cause the buffing wheel carriage to move upwardly at twice its normal down speed, until the limit switch I I is actuated by the stop lug Id, thus shutting off the auxiliary motor I5, the motor of the timer l4, and the applicator motor 59.

When the motor switch is closed by the operation of the starting push button 8, the buffing wheel motor, the timer motor, and the compound applicator motor 19 will be simultaneously turned on.

After a predetermined period of time, to 15 minutes, for example, the timer motor t l will cause the down switch 22 to close, which in turn will start the auxiliary motor l and move the buffing wheel carriage down a short distance toward the work. This motion will continue until the increase of current in the buifing wheel motor circuit due to the increased pressure between the bufiing wheel and the work will actuate the current relay 6, and throw off the down switch 22,

thus stopping the auxiliary motor 5*- 'ihese conditions will continue until the down switch is again closed by the continued operation of the adjustable timer motor M. After this operation has been repeated a good many times, the buiiing wheel (BW) will be worn down to a predetermined hub size, and at that time, the limit switch it will be actuated by the adjustable stop lug is mounted on the carriage plate The motor switch 3 will thus be opened, which of course will stop the operation of the timer motor E4 and the applicator motor [9.

At this time, the down switch 22 will be automatically opened, and the up switch 23 will be closed.

It will thus be seen that the timer motor i l controls the successive operations of the auxiliary motor I 5 merely on the down strokes, and that the timer motor will run only so long as the buffing wheel I is operated.

It will also be noted that the contacts Ma and 82b on the down switch 22 serve to introduce a shunt or short circuit across the terminals 85, 86 of the current relay Also, when the switch 22 is open, the upper movable arm 82 will be connected with the wires 83, 3d, and under these conditions the two contacts or" the current relay 4 will be prevented from objectionable vibrations.

In the modified form of the invention shown in Fig. 9, the bufiing wheel BW is mounted on a shaft TE, having a pulley ID, driven by a multiple belt IB receiving power from a pulley 'lC mounted on the shaft of an electric motor TA.

It will be understood that wherever reference has been made to a bufiing wheel in the specification and claims, this expression is to be construed as also covering polishing, grinding, scratch-brushing, burring, and other types of abrading wheels within the spirit and scope of the invention.

One advantage of the present invention is that the bufling wheel motor and the auxiliary motor are both mounted on the same head or frame, whereby they will be moved together as a unit when the angular position of the buffing wheel is being adjusted.

A further advantage is the provision of apparatus for automatically throwing on the automatic bufiing compound applicator and the timer motor whenever and only when the bufiing wheel is rotating.

A still further advantage is that the bufling wheel motor can never become overloaded due to manual maladjustments and therefore the full use of said motor at its maximum rated horsepower will be permitted.

While there has been disclosed in this specification two forms in which the invention may conveniently be embodied in practice, it is to be understood that the invention is not to be limited to such forms, but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fuly described the invention, what is claimed as new and for which it is desired to obtain Letters Patent is:

1. In an automatic buffing machine, a bottom support frame, a post mounted in said frame and projecting upwardly out of the top thereof, a carriage for a motor-driven buffing wheel mounted for universal adjustment upon the top of said post, means within said frame for adjusting the elevation of said post, and other means in said frame for swinging said post within limits about a vertical axis.

2. A machine as defined in claim 1, in which the intermediate portion of said post is inclined so as to offset the bufiing wheel carriage laterally substantialy over the center of said support frame.

3. A machine as defined in claim 1, in which the intermediate portion of said post is inclined laterally and provided on its under surface with a reinforcing rib.

l. In an automatic bumng machine, a buffing wheel carriage, a bottom support frame, an upstanding post supported at its bottom end in said frame, means for varying the angular position of said post around a vertical axis, means to vary the elevation of said post, and means to mount said carriage universally upon the upper end of said post whereby said buffing wheel may engage the work at any desired horizontal, vertical, or angular position within limits.

5. In an automatic bufiing machine, a support frame, a buffing wheel carriage mounted in said frame, a motor-driven bufiing wheel mounted on said carriage, a carriage feeding auxiliary motor also mounted on said frame, timer means to cause said auxiliary motor to automatically drive said buffing wheel intermittently toward the work, means to stop said auxiliary motor when the pressure of said bufiing wheel against the work attains a predetermined value so as to maintain said wheel in constant engagement with said work with a pressure varying within a limited range, a switch for reversing said auxiliary motor, and means for operating said switch when said bufiing wheel is worn down to a predetermined diameter.

6, In an automatic bufiing machine as defined in claim 4, the upper end of said post being provided with a transverse flange, an angle plate swiveled on said flange, said carriage being swiveled on said angle plate.

7. In an automatic bufiing machine as defined in claim 4, wherein said bufiing wheel carriage is mounted to slide toward the work, and electrical apparatus for causing said carriage to be fed forward intermittently so as to maintain said buifing wheel in constant engagement with the work with a pressure varying within a limited range.

8. In an automatic bufiing machine, a stationary supporting frame, a carriage slidably mounted in said frame, a motor-driven bufiing Wheel mounted on said carriage, a carriage-feeding auxiliary motor mounted on said frame, a motoroperated timer to start said auxiliary motor intermittently at predetermined cycles of time intervals, and means to stop said auxiliary motor when the pressure of said buffing wheel against the work attains a predetermined value so as to maintain said bufiing wheel in constant engagement with said work with a pressure varying within a limited range.

9. In an automatic buffing machine as defined in claim 8 having a motor-operated applicator mechanism to automatically apply buffing compound to said builing wheel, and unitary switch means for simultaneously starting and stopping said buffing wheel motor, said timer motor, and said applicator motor.

10. In an automatic buffing machine as defined in claim 8 having a motor-operated applicator mechanism to automatically apply bufiing compound to said buiiing wheel, unitary switch means for simultaneously starting and stoping said buffing wheel motor, said timer motor, and said applica'tor motor, and signal means for indicating to the operator when the rouge cake of said applicator requires renewal.

11. In a buffing machine, a sliding carriage, a motor-operated buffing wheel mounted on said carriage, an auxiliary motor, means driven by said auxiliary motor to slide said carriage and cause the bufiing Wheel to, move closer toward the work being buffed, a timer-operated switch for intermittently starting said auxiliary motor at predetermined cycles, a current relay in circuit with said bumng wheel motor, means responsive to the development of a predetermined rise of current in the buffing wheel motor circuit due to the increasing pressure of said wheel against the work, to operate said relay, means responsive to the operation of said relay to stop said auxiliary motor whereby said buffing wheel will be maintained in constant engagement with said work with a pressure varying within a limited range.

12. A bufling machine as set forth in claim 11, in which said auxiliary motor switch has a, pair of fixed contacts, and means to connect said contacts across the terminals of said current relay whereby the relay will be deenergized when said auxiliary motor switch is opened, to permit said current relay to be reset rapidly after each operation thereof and to thus prevent the chattering of said relay.

13. In an automatic buffing machine unit, a stationary frame, a carriage 'slidably mounted in said frame, a rotating work-holding spindle, a motor-driven bufi'ing wheel mounted on said carriage, an auxiliary carriage-driving motor mounted on said stationary frame, means to cause said auxiliary motor to intermittently and automatically drive said carriage toward the work at predetermined adjustable time intervals so as to maintain said bufiing wheel in constant engagement with the work with a pressure varying within a limited range, and a current relay in circuit with the bufing wheel motor for temporarily stoping said auxiliary motor when the current in the bufiing wheel motor circuit has risen to a'predetermined value, and time mechanism to thereafter start said auxiliary motor again at the end of a predetermined interval of time.

PAUL J. BELC'OURT.

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