US1570376A

US1570376A - Wheel feeding and adjusting means for grinding machines

Info

Publication number: US1570376A
Application number: US647118A
Authority: US
Inventors: John A Doane
Original assignee: Pratt and Whitney Co Inc
Current assignee: Pratt and Whitney Co Inc
Priority date: 1923-05-31
Filing date: 1923-06-22
Publication date: 1926-01-19
Anticipated expiration: 1943-01-19

Description

V v J. A. DOANE 'WHEEL FEEDING AND ADJUSTING MEANS FQR GRINDING MACHINES 2 Sheets-Sheet 1 Original Filed. y 1, 192;

lllllml IIIIILTT' WHEEL FEEDING AND ADJUSTING MEANS FOR GRINDING MACHINES Original Filed ay.- 1, 192.3 2, Sheets-Sheet -2 ii 9' W III/IIIIIIIIIIIIIIIIIIIII.Ejfl1 20 INVENTGR.

10 k I B A I ATTORNEY,

Patented Jan. 19, 1926.

UNITED STATES PATENT OFFICE.-

JOHN A. DOANE, OF HARTFORD, CONNECTICUT, ASSIGNOB T0 PRATT & WHITNEY OF NEW YORK, N. Y., A CORPORATIONOF NEW JERSEY.

COMPANY,

WHEEL FEEDING AND ADJUSTING MEANS FOR GRINDING MACHINES.

Original application filed Kay 31, 1923, Serial No. 642,813. Divided and this application filed June 22, i

1923. Serial No. 647,118.

To all whom it mar concern:

Be it known that I, JOHN A. DOANE, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Wheel Feeding and Adjusting Means for Grinding Machines, of which the following is a specilication.

This invention relates to. grinding. ma-

' chines and in particular to an improved form of feeding and adjusting mechanism for the wheel of a vertical surface grinder.

An object of the present invention is to provide feeding mechanism ada ted to continue the feeding movement of t e wheel toward the work support of a grinding machine until a predetermined. position is reached relative to the work at which point the feed is discontinued.

Another object of the invention is to provide electrically actuated -means normally holding parts of the feeding mechanism in operative relation and to provide means rendering the electric feeding mechanism inoperative at. any predetermined point so that the downward movement of the wheel may be interrupted precisely at any predetermined point. 7

Another object of the invention is to prov'dc the feed pawl for the feeding mechanism so that it may be moved into and out of operative position relative to a ratchet wheel, and to provide an electro-magnetmaintaining the pawl 1n its operative position so long as the magnet is energized, means being provided for moving the pawl to its inoperative position as soon as the,

magnet is de-energized.

Another object of the invention is to provide an improved feeding or adjusting mechanism for the wheel of a grinding machine having a wide range of adjustment and one permitting the parts to be manually moved so that the machine may be adapted for a wide range of work.

This application forms a division of my 'copending application Serial. No. 642,613

filed May be described in connection with a grinding machine of the same ty e as described in the above mentioned app ication.

With these and other objects in view my invention consists in the features of con- 31, 1923, and this invention will .struction and operation set forth in the following-specification and illustrated inthe accompanying drawings. z

In the accompanying drawin annexed hereto and forming a part of this specification, I have shown my invention embodied in a vertical surface grinding machine but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a side elevation of a ortion of a surface grinder, parts being' roken away to more clearly show the construction of the feeding mechanism.

Fig. 2 is a plan view of a portion of the machine having parts broken away to more clearly show the feeding mechanism.

Fig. 3 is a sectional view upon an enlarged scale of the feed actuating mechanism.

Fig. 4 is a view of the parts shown in Fig. 3 taken from the rear of the machine.

Fig. 5 is a cross sectional view of the manual adjusting mechanism.

Fig.6 is an elevation of the parts shown present invention comprises in addition to the base, column and work support of a surface grinding machine, the following principal parts: First, a wheel head on thecolumn having a wheel spindle and abrasive wheel rotatably mounted thereon and slidably mounted so that it may move toward or from the work support; second, a rotatably mounted adjusting screw in the column for varying the vertical position of the wheel head; third, a shaft adapted to rotate said screw; fourth, a member adapted to be reciprocated' while the machine is in use; fifth, a pawl actuated by. said member through members mounted concentric with the shaft to rotate the shaft; sixth an electro-magnet supporting the pawl in operative position; and seventh, an adjustable member carried by and rotating with the feed shaft and its connected parts to disengage the pawl by de-energizing the electromagnet and rendering the wheel feed inoperative.

Referring more in detail to the figures of the drawings, I show a machine base 10 having a work supporting and rotating member 11 thereon. This support which is in the form of a table forms no part of the sresent invention and may be of any other esired form. Supported on the base 10 is a column 12 having vertical ways 13 on opposite sides on which a wheel head 14 is slidably mounted. Within this wheel head 14 is a rotatably mounted wheel spindle 15 on which is an abrasive wheel 16. Suitable driving means for the wheel spindle 15 are provided, such as a motor or other means contained within the machine base 10, which may rotate the spindle 15 and wheel 16 at a high rotative speed through suitable flexible connections as shown in my copending ap lication.

l otatably mounted adjacent the head 14 and within the column 12 is a wheel adjusting screw 18 sup orted against axial movement and threa edly engaging the wheel head 14 so that rotation of the screw 18 varies the vertical position of the head 14. On this screw 18 is a worm wheel 1:; fixed thereto so that a worm 20 mounted on a horizontally extending shaft or rod 21 may be used to rotate it in either direction and thus adjust the position of the wheel 16 relative to the work support. The shaft 21 is rotatably mounted within a member 22 fastened in a horizontal position to the column 12.

Associated with the driving mechanism for the work table 11 or other constantly actuated member so that it may be constantly reciprocated through a fixed distance at all times while the machine is in operation is a vertical rod 23. This extends to a point adjacent the shaft 21 for controlling the vertical movements of the head 14. It is from the reciprocatory movements of this vertical 'rod 23 that all of the automatic feeding movements of the wheel 16 are accomplished. As the means for actuating this vertical rod may be the same as those defined in my co ending application, they have not been il ustrated or described in this application.

The shaft 21 carrying the worm 20 is extended both to the front and rear of the machine and is preferably in the form of a hollow shaft. At its forward end, it is provided with a hand wheel 24 directly fastened thereto by means of which it may be rotated to manually raise or lower the wheel head 14. At its rear end, the shaft 21 is pro vided with parts for automatically feeding the wheel toward the work support step by step. Also at the rear end of this shaft is the mechanism for discontinuing the feed at any predetermined point. These presently will be described.

During operation of the machine, the

wheel 16 together with the wheel head 14 within which it is mounted, is usually first manually adjusted to engage the wheel 16 with the work on the work support 11. Thereafter the automatic feed for the wheel 16 is started which continues the downward movement of the wheel during the actual grinding period. l/Vhen a" predetermined position of the wheel 16 relative to the work support 11 is reached, dependent upon the thickness of the work being ground, the downward movement of the wheel 16 is sto pod and the wheel is then returned manual y to its upper or inoperative position.

The means to rotate the shaft 21 and its worm 20 by power means, preferably *by a step by step movement, to slowly feed the wheel and to stop its movement comprise the principal portions of this invention. The upper end of the rod 23 contacts with an extension formed on an oscillating member 26 rotatably mounted with a bushing 27 on the hollow shaft 21. This member 26 is provided with a pawl 28 which is mounted on a member 29 so that it may be moved to inoperative and operative positions. So long as the machine is in operation, this vertical rod 23 is actuated to constantly oscillate the member 26, means presently to be described being made use of to limit the oscillatory movement of this member.

On the hollow shaft 21 carrying the worm 20 is a ratchet wheel 30. This is keyed to a portion of the bushing 27 so that it rotates with the shaft 21. The position of the ratchet wheel 30 on the hollow shaft 21 is such that the ratchet wheel 30 may be engaged by the pawl 28. This ratchet wheel 30, therefore, so long as the member 26 carrying the pawl '28 is oscillated, will be rotated step by step through small angles with each oscillatory movement of the vertical rod 23, if the pawl 28 is in its operative position. This rotation of the ratchet wheel 30 by the automatically actuated pawl rotates the screw 18 in a direction to cause the wheel 16 to be fed downward against the work. When the pawl 28 is moved to its inoperative position so that it is disengaged from the ratchet wheel 30, the shaft 21 may be rotated manually by the hand wheel 24.

The oscillating member 26 carrying the feed pawl 28 is normally held by means of a spring 32 with one of its arms 33 in contact with an adjustable stop member 34. This is clearly shown in Fig. 4. Vertical movement of the actuating rod 23 oscillates this member 26 away from the stop 34 to advance the ratchet wheel and feed the wheel 16 downward. By varying the position of the stop member 34, as for instance by rotating it to raise or lower its lower end, oscillatory movements of the member 26 will be varied either to increase or decrease the amount of feeding movement for the wheel head 14 for each upward movement of the actuating rod 23.

The oscillating member 26 has mounted within its body portion an electro-magnet 36, the coil terminals of which are shown in Fig. 3. The armature bar of this magnet 36 is mounted on an arm 37 on the member 39 carrying the pawl 28. When the magnet 36 is energized, this pawl carrying member 39 is slightly oscillated to a position allowing the awl 28 to engage the periphery of the rate iet wheel 30. With the magnet 36 deenergized, the pawl carryin member 29 is oscillated by the spring 38 s own in Fig. 4 to a position so that the pawl 28 is held from engagement with the ratchet wheel 30. As long as the magnet 36 is energized, therefore, the pawl will act to feed the wheel 16 and, as soon as the magnet 36 is deenergized, the feed will be sto ped.

Associated with t iese wheel feeding means are the devices enabling the feeding movement of the wheel 16 to be repeatedly stopped at any predetermined exact point. For this purpose, the pawl 28 is held in operative engagement with its ratchet wheel 30 by the magnetic means as above described during the desired amount of feeding movement. The electro-magnet 36, housed on and oscillating with the member 26, holds its armature toward itself so that the pawl operates to feed the wheel only when it is energized. Just as soon as the magnet is de-energized, the oscillating. member 29 moves the pawl 28 to its inoperative position so that the feeding movement is promptly stopped.

To interrupt the circuit for this electromagnet'36 so that the pawl 28 may b ade inoperative, a contact is made throng the' ratchet wheel 30 which may be broken at any desired time. This ratchet wheel 30 has contact rings 40 on o posite sides joined electrically together and completely insulated from the gage these rings 40 so that current normally flows directl from one of the contact rings 40 to the ot ier ring, this circuit including.

also a source of current shown diagrammatically in F 1g. 3 and the electro-magnet 36. The circuit, too. may include a man-- ually operated switch 42 as shown in the diagrammatic View of the circuit. One of the contact plugs 41 constantly rides on its contact ring 40 but the opposite contact 41 is adapted to be forced away from its ring 40 by an arm 45 adjacent to and adapted to rotate with the ratchet wheel 30. The free end of this arm 45 adjacent the contact ring wheel 30. Contact plugs 41 en- 40 is made of suitable insulating material. It will be seen therefore that by setting this arm 45 in a redetermined rotative osition relative to the ratchet wheel 30, w enthe grinding operation is being started, the electric circuit controlling the movement of the pawl 28 may be interrupted and the pawl 28 thrown out of its operative position at any desired point during the downward feeding movement .of the wheel 16. This interruption to the feeding movement of the wheel 16 occurs when the arm 45 contacts with one of the contact plugs 41 and lifts it from its contact ring 40, thus opening the circuit for the electro-magnet 36.

To adjust the position of the arm 45 so that it may be used to disconnect the wheel feeding movement at different points, it is carried on a member in the form of a hub 46 which is fastened directly to a rod 47 extending entirely through the hollow shaft 21. At the forward end of this shaft 21, the rod 47 is fastened to a hub member 48 by means of a suitable pin or other fastening means. This hub member 48 is provided with a clamping screw 49 passin through it and which engages a circular slot in the hand wheel 24. The slot is of recessed form so that the head of the screw49 may be retained within the slot. A clamping nut 50 on the screw 49 enables the hub 48 to be clamped tothe wheel 24 in any rotative position. To vary the relative rotative positions of the arm 45 and the worm shaft 21, it is only necessary to release the clamping nut 50 and rotate the hub member 48 to any point desired. Thus, by clamping this member 48 in predetermined position relative to the hand wheel 24 and the hollow shaft 21, the feed may be continued for any desired distance and then disconnected at a precise predetermined point. To aid in positioning the arm 45, graduations 51 may be provided on the hub member 48 adjacent a zero line on the hand wheel 24.

As the pawl 28 in its operative position would prevent manual adjustment of the wheel 16 in an upward direction, I provide the manually actuated switch 42 included within the circuit for the electro-magnet 36.

By opening this switch 42, the pawl 28 is moved to its inoperative position by oscillation of the member 29 carrying it. In this way, the hollow shaft 21 and the parts carried thereby may be rotated freely in either direction by the hand wheel 24 on the forward end of the hollow shaft 21 and the wheel 16 adjusted to any desired vertical position.

From the above. it will be seen that convenient means are provided to automatically feed the wheel 16 of a grinding machine downward to a position which is adjustable for different thicknesses of work. Also. means. are provided to quickly adjust the vertical ment with sai lposition of the wheel 16 manually. To enab e the operator to determine the ad justment of the wheel for different thicknesses of work, raduations 53 may be provided on a mem er 54 frictionally mounted on the hub of the hand wheel 24. On the forward end of the member 22 carrying the hollow shaft 21 is a zero line 55 adjacent and cooperating with the graduations 53. By means of these graduations 53, the wheel may be raised or lowered manually or lowered by the power means a precise distance.

What I claim is:

1. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a rotatably mounted screw engaging the wheel head so that rotation of the screw is adapted to vary the position of the wheel head, a shaft, means connected to said shaft whereby it may rotate the screw, a reciprocatory actuating rod for said feeding mechanism means connecting said actuating rod with said shaft, electro-magnetic means rendering said connecting means operatlve, and means for de-energizmg said electro-magnet to render said connecting means inoperative.

2. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a rotatably mounted screw engaging the wheel head so that rotation of the screw is adapted to vary the position of the wheel head, a worm wheel on said screw, a shaft havin a worm thereon in engageworm gear, a ratchet wheel normally rotated with said shaft, a pawl normally'in engagement 'with said ratchet wheel, and electro-magnetic means to render said pawl inoperative at any predetermined point in the rotation of said ratchet wheel.

3. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a rotatably mounted screw engaging the wheel head so that rotation of the screw may vary the position of the wheel head, a worm wheel on said screw, a shaft having a worm thereon in en agement with said worm gear, a ratchet w eel normally rotated with said shaft, a pawl normally in engagement with 1 said ratchet wheel, an

oscillatory member mounted concentrically.

with said shaft supporting the pawl, and means to oscillate said member into and out of a position to engage the pawl with said ratchet wheel.

4. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a rotatably mounted screw engaging the wheel head so that rotation of the screw may vary the position of the wheel head, a worm wheel on said screw, a shaft having a worm thereon in en agement with said worm gear, a ratchet w eel normally rotated with said shaft, a pawl normally in engagement with said ratchet wheel, an

oscillatory member mounted concentrically with said shaft supporting the pawl, means to oscillate said member into and out of a position to engagethe pawl with said ratchet wheel, and means adjustably carried by said ratchet wheel to disengage the pawl therefrom at any predetermined position of the wheel head.

5. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a constantl reciprocating member, a ratchet wheel a apted to be rotated thereby to feed the wheel head, an electromagnet adapted when energized to hold the pawl in its operative position to rotate the ratchet wheel, and means to break the circuit for energizing said electro-magnet at any predetermined point in the rotation of said ratchet wheel to stop further movement of the wheel head.

6. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a constantly reciprocating member, a ratchet wheel adapted to be rotated thereby by means of a pawl oscillated by said reciprocating member, a circuit including an electro-magnet and a suitable source of current, contacts in said circuit ineluding said ratchet wheel, and an adjustable member adapted to rotate with the ratchet wheel to interrupt the circuit atany point in the rotation of said ratchet wheel and stop further movement of the wheel head.

7. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a. constantly reciprocating member, a ratchet wheel adapted to be rotated thereby to feed the wheel head, an electric circuit having an electro-magnet therein and having contacts adjacent the ratchet wheel, and means toseparate one of said contacts when the ratchet wheel has been rotated to a predetermined position,

whereby said feeding mechanism is rendered inoperative.

8. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a constantl reciprocating member, a ratchet wheel a apted to be rotated thereby to feed the wheel head, an electric circuit having an electromagnet therein and having contacts adjacent the ratchet wheel slip. rings on said ratchet wheel engage by said contacts, and adjust able means normally rotating with the ratchet to separate one of said contacts when the ratchet wheel has been rotated to a predetermined position whereby said feeding mechanism is rendered inoperative.

9. A feeding mechanism for the wheel head of a grinding machine comprising in combination, a constantly reciprocating member, a ratchet wheel ada ted to be rotated thereby to feed the whee head, a pawl normally held in operative position relative to the ratchet wheel,an electric circuit having an electro-magnet therein and having contacts adL'acent the ratchet wheel, slip rings on said ratchet wheel engaged by said contacts, means to separate one of said contacts when the ratchet wheel has been rotate-"l to a predetermined position to move the pawl to its inoperative position whereby said feeding mechanism is rendered inoperative.

;In testimony whereof, I hereto aflix my signature.

- JOHN A. DOAN E.