US2585365A - Clutch and brake for grinding apparatus - Google Patents

Description

1952 R. E. ALLEN ETAL CLUTCH AND BRAKE FOR GRINDING APPARATUS 2 SHEETSS!-1EET 1 Filed March 20, 1948 INVENTOR. ROBERT E. ALLEN WILLIAM F. UTZINGER BY MA.

A TTOR/VE Y 1952 R. E. ALLEN ETAL CLUTCH AND BRAKE FOR GRINDING APPARATUS 2 shuts-SHEET 2 Filed March 20, 1948 INVENTOR. TE. ALLEN u INGER so ROBER WILLIAM F BY A 77' ORA/E Y Patented Feb. 12, 1952 CLUTCH BRAKE "FOR GRINDING APPARATUS Robert Allen and William F. Utzinger, Dayton, Ohio, :assig'nors to The Univis Lens Gompany, Dayton, Ohio, :a corporation of Ohio ApplicatiomMa-rch' 20, 1948, Serial -No. usual (01. lac-.18.)

- .1 Claim.

invention relates to lens grindin :apparatus for processing lens blanks, and .more par- :ticularly to improvements in the construction of high-speed lens grinders.

One of the objects of this invention is to :prowide high-speed lens grinding apparatus having a rotating spindle for supporting a lens blank in .a grinding position, which can be :rapidly started and stopped with .a minimum of power, and which can he longitudinally displaced while being driven at high speed.

Another object of the invention is to provide for an apparatus of the character described a lightweight clutch mechanism for engagin and disengaging the spindle with the power source supplying the driving torque.

It is also an object to provide .a braking mechanism for a high-speed grinder of the type set vforth, the brake mechanism operating independently of the power source supplying the driving torque to the spindle and applying braking .power to the spindle to stop the rotation thereof rapidly.

Still another object to provide in a highspeed .lens grinder a hollow spindle adapted to :be

"rotated about .its longitudinal axis at high speed and also mounted for reciprocating motion while being rotated. the clutch mechanism operating to engage during the entire movement of the spindle in-one direction and disengaging when the spindle moves in the opposite direction, and .hav-

ing a brake mechanism operating to stop the rotation of the spindle when the clutch mechadisengages. Another :of the objects resides in the provision of a protecting device which operates to iprevent abrasive particles from entering the hearing surtaces of the spindle.

Further objects and advantages of the present invention will .be apparent from the following description, reference being .had to the accompanying drawings wherein a preferred term of embodiment of the invention is clearly shown.

In the drawings:

1 is a front elevational view of one :form

of lens grinding apparatus, the operatinghandle being shown in the raised position;

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. .1; and

Fig. 3 is a top elevational view, partly in sec-- tions, taken on the .line 3-3 of Fig. .1, and illustrating the operating handle in the down position.

Referring further to the drawings, the quill housing 1.0 is formed with asubstantiallycircu-lar cross section having a central bore therein. This housing is also termed with an integral .hracket portion l8 having :a flanged edge 14 by which it can be mounted in operat ng p sition, as Joy means of the bolt and washer indicated at 15 Eig. i2 tor example.

Housing I 0 provides an outer supporting memher for the spindle sleeve :11. This-sleeve. which can be formed from a piece of steel tubing if desired, is reciproca'hly mounted within the housing ill as seen in Big. 3. ill-he sleeve is formed with an elongated keyway is at one .side thereof. A key I9, secured to the housing In with a cap screw 2d,.is-receivedwithin this keyway toprevent the sleeve l I from rotating relative to the housing I ll. To provide for raising and lowering thersleeve within the housing, on the opposite side from the .keyway i8, teeth :22 are out to ,form a rack cooperating with the pinion 23. The pinion is in turn mounted upon the shaft 2-4 and driven Soy .means of the ieed lever 2-5 and handle 26 in the usual manner.

The spindle 3B is rotatably mounted within the sleeve H. This spindle, which is formed with a central bore 3! extending .immend to end, seats at its upper end within a tapered roller bearing :32 retained within the upper :end of sleeve H. At its .upper end the central bore 31 is enlarged and threaded. The tapered end of a nose piece 35 is fitted into the enlarged bore. Nose piece :35 is also provided with a central bore, aligning with the bore 3L, .and of sufiicient diameter to receive the hollow stemmed and threaded bolt .36.

At the lower end of sleeve H, the spindle 30 is provided-with a ball bearing 40 seated against :a shoulder .formed therein. This bearing is retained in position by the nut 4| and adjusted by means of the nut-s 42. With this construction, it will be readily apparent that the spindle 30 is :free to rotate relative to the sleeve 1 1..

Closing the lower end of housing I0 is a pulley sleeve 45 connected thereto by means of a set screw 46 and formed with a depending collar upon which the pulley 4Z1 ismounted. The sleeve 45 and pulley 4 1 are formed with central bores therein through which the spindle =30 extends as shown in Fig. 2. A ball bearing 48 seats against the shoulder on the pulley sleeve collar, lacing retained in position by the U--shaped retainer ring "49. A set screw ':5l .is received through the center of the pulley belt groove to aid in retaining the bearing in position. At the upper end of the pulley a passage 52 having a pressure :type of lubrication fixture 53 fitted therein communicates with the bearing 48 for the purpose of supplying a lubricant thereto. oiliseal 54 provided to, retain the vlubricant when applied under pressure. The pulley 6'! is thus mounted for free rotation relative to the sleeve 45. A driving connection with the spindle 30 is obtained through a clutch mechanism.

The clutch mechanism has a cup-shaped clutch drum of aluminum connected to the bottom of the pulley 41 by means of dowels 58 and fiat-headed machine screws 59. This drum is provided with a central aperture through which the spindle passes freely. The annular side walls of the drum 5'! are tapered downwardly from the top and are adapted to engage with similarly tapered side walls of the clutch shoeBl.

The clutch shoe BI is also formed of aluminum and is provided with a central sleeve portion 62 through which the spindle 3D is received. The

annular side walls of this shoe have a leather clutch facing 63 riveted thereto. Thus when the shoe Si is moved up into the position illustrated in Fig. 2 the clutch facing 53 engages with the inner surface of the side walls of the drum 51. Since the drum 5'! is rotated by the driven pulley 41, the shoe 6| being in engagement with the drum is also driven. When the shoe is moved down out of engagement with the drum the driving connection therebetween is broken.

In order to drive the spindle 30, the lower end thereof is formed with a pair of oppositely disposed keyways 65 and 66. These keyways extend upward along the spindle and terminate in the shoulders 61 and 68. The interior of the sleeve 62 is similarly provided with keyways so that the shoe 6| can be connected thereto. A pair of oppositely disposed keys H! being received in these keyways and retained in position by means of a pair of fiat-headed machine screws H for this purpose. With this construction, the spindle is free to move up and down vertically relative to the sleeve 62 i. e., shoe 6i. It is rotated therewith, however, by means of the driving connection efiected through the keys (0.

At its lower end the sleeve 62 is slidably received within the retainer sleeve 15. This sleeve, through which the spindle 30 also extends, is locked thereto by means of the key 16 and set screw 11. The coiled clutch spring 18 is retained in position by this sleeve with one end seating against the underside of the clutch shoe 6| as seen in Fig. 2. Thus when the spindle is raised the sleeve 15 moves upward relative to the sleeve 62. Spring 18 is compressed until further upward movement causes the shoe 6! to move up into driving engagement with the drum 51. This construction provides one of the features of this invention. Thus when the compression of spring 18 is properly adjusted a slight upward movement of the spindle will engage the clutch members 5! and BI and a rapid starting of the spindle rotation is obtained. Further upward movement of the spindle can also be obtained where it is desired to vary the vertical movement of the spindle relative to a work piece supported above the upper end of the spindle for example. As will be readily apparent from the construction disclosed, such further upward movement only tends to compress the spring 18 to a greater extent and maintains a tighter engagement between the drum 5'! and the shoe 6|. Thus substantial vertical movement of the spindle can be obtained without effecting the driving engagement between the clutch members 51 and BI.

To provide for a rapid stopping of the fast rotating spindle when the clutch drum and shoe 4 are disengaged, an annular brake ring 80 is pr6- vided. This ring is mounted on a pair of brackets BI and 82 secured at their upper ends to the housing [0 by means of cap screws. The ring is secured to the lower ends of the brackets by means of cap screws and is maintained in spaced relation with respect to sleeve hand the lower end of the clutch shoe 6| thereby. A ring of brake lining 83 is secured to the upper side of ring 80 by means of rivets. Thus when the clutch members are disengaged, the shoe 6| moves down and the lower edge thereof engages with the brake lining 83 and the rotation of the spindle stopped. It is to be noted in this construction that another of the features provides for downward vertical movement of the spindle without disengaging the clutch members and applying the brake until the shoulders 61 and 68 move down sufiiciently to strike the keys It. Any further downward movement of the spindle disengages the clutch members by forcing the shoe 6! away from the drum 5? and into contact with the brake ring 39. A very rapid braking action is thereby provided which enables the operator to wait a minimum of time only forthe spindle to stop rotating when changing operation or work pieces, for example.

To complete the assembly, this high-speed grinder is provided at its upper end with a pan base which is mounted over the endof sleeve ll, being secured thereto with a set screw 9|. This base is formed with. a central "opening through which the upper end of spindle 30 projects. It is also provided with a passage 92 communicating at its inner end with thebearing 32. A fitting 93 is mounted at the outer end of this passage to provide for forcing lubrication under pressure into the bearing. An oil seal 94 is provided to prevent the loss of lubrication along the exterior surface of the spindle at the top thereof. The pan base 98 is thus free to move vertically with the sleeve H, but does not rotate with the spindle 36. Supported on the pan base is the water pan 96 which is formed with a central opening therein through which :the upper end of the spindle extends as seen in Fig. 2. This opening is of sufiicient diameter for the pan 95 to seat down on the annular shoulder 91 formed at the top of the pan base 90. This shoulder is recessed on the interior adjacent the central bore to provide for mounting the oil seal '94.

To further protect the bearing 32 and rotating surfaces at the upper end of the spindle against the'entrance of abrasives carried in the liquid flow from the work operations performed within the water pan, a cap or flinger'lili'l is provided. This flinger is provided with a central opening therein and is received over the upper end of the spindle, being held in place by means of the set screw II. The fiinger is formed with annular depending side walls [02 which extend down almost to the shoulder 91. These walls are maintained in spaced relation to provide sufiicient clearance for their rotation with respect to the upwardly projecting shoulder 91 of the pan base 90. Since these walls overhang the shoulder 91, which provides through the oil seal 94 the only entrance from the interior of the pan 96 to the bearing 32, and since they are rotated at a high rate of speed with the spindle 30, they tend'to fling the abrasive particles outwardly and away from the inner rotating surfaces. Such construction has been found to increase the useful life of the machine very considerably, the machine requiring less servicing and operating over longer periods of time under adverse conditions with fewer repairs necessary.

A stop rod I05 having a centrally positioned and elongated slot I06 formed therein is threadedly connected at its upper end to the pan base 90. At its lower end this rod, which is received within a bore I01 formed in the projecting boss I08 in the lower part of housing I0, is provided with a brake shoe holder I09, Fig. 1. At the upper end rod I 05 is guided through the bifurcated boss IIO formed as an integral part of the housing I0, Fig. 3. An adjustable stop member H2 is bolted to the rod I05 to provide for controlling the amount of vertical movement effected by the sleeve II. The upper edge of the stop is adapted to strike against the under surface of the projection IIO, while the under side of the stop in turn strikes against the upper surface of the boss I08. The movement of the sleeve I! can thus be adjustably controlled as desired.

To further facilitate operation of the apparatus, a pulley I20 is mounted on the pinion shaft 24. A weight can be attached to this pulley to facilitate the raising and lowering of the handle 26 and the connected sleeve H.

In operation, a vacuum fitting can be attached to the lower end of the spindle 30 for applying suction action through the bore 3!. A vacuum type of holder for the lens blank is then mounted and retained by the suction action upon the nose piece 35. Then the operating handle 20 is raised and lowered by the operator to bring the lens holder into and out of contact with the tool being used to' process the lens blank. Such movement of the handle in one direction rotates the pinion shaft 24 and pinion 23 to raise the sleeve I'I. Movement in the opposite direction reverses the rotation of shaft 24 and lowers the sleeve ii. The upward movement of the sleeve I! in turn raises the spindle 30, which is connected thereto with bearings, and which permit rotation of the spindle relative to the sleeve.

To provide for the rapid starting of the spindle 30 to rotate about its longitudinal axis, driving torque is transmitted from the pulley 41 connected to a power source. This pulley is directly connected to a clutch mechanism comprising a drum 5! and a shoe 6 I. The pulley and drum are mounted for free rotation with respect to the spindle 30. The clutch shoe is keyed to the spindle. Thus when the drum and shoe are engaged the spindle is driven, and when these clutch members are disengaged'driving torque is no longer transmitted to rotate the spindle.

The drum 5'! is driven constantly and the shoe BI moved into and out of driving engagement therewith by raising and lowering the spindle 30 as desired. Since the spindle is free to move vertically, but not rotationally, with respect to the clutch shoe 6|, the retainer sleeve I5 and spring I8 provide for vertical movement both up and down, within predetermined limits, while the clutch members are engaged and the spindle rotating at full speed.

In order to provide for rapid braking to stop the spindle from rotating after the clutch members are disengaged, a brake ring 80 is mounted in position beneath the clutch shoe 6|. Thus when the operator causes the spindle to move down sufficiently to disengage the clutch members the lower edges of the shoe 6| come in contact with the brake ring 80 and the rotation of the spindle is stopped.

It will be apparent from the above description that there is provided an cfiiciently operating apparatus particularly adapted for lens grinding operations. Both rapid starting and stopping of the spindle rotation are effected, the mass of the parts involved in these operations being relatively light. Thus the motor supplying the driving torque for rotating the spindle at high speed does not have to be started and stopped when it is desired to similarly control the operation of the spindle. The brake operates against only the mass of the hollow spindle and aluminum clutch shoe 6| when applied. It is also only necessary to move these same members when the clutch members are engaged and the spindle rotated. Furthermore, when the clutch members engage to drive the spindle, the spindle can be moved vertically upward without disengaging the clutch. Also, when the spindle is moved in the opposite direction the brake mechanism is applied to stop the rotation. There is also provided a fiinger which prevents abrasive particles from entering the bearing surfaces from the upper end of the spindle.

While the forms of embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claim which follows.

We claim:

A lens grinding apparatus, in combination a spindle housing, a spindle sleeve reciprocably mounted within said housing, a spindle rotatably mounted within said sleeve, rack and pinion means connected to said sleeve to provide for reciprocating said spindle, a pulley rotatably mounted relative to said spindle for receiving a driving torque from a power source, a clutch drum connected to said pulley and a clutch shoe having a slidable connection with said spindle, said drum and shoe being constructed and arranged to move into driving engagement with respect to each other upon longitudinal movement of the spindle in one direction and out of such .1 engagement upon similar movement of the spindle in the opposite direction, said slidable connection providing for said engagement of the shoe with the drum and thereafter continued longitudinal movement of the spindle in either direction with the shoe and drum remaining in engagement, and a brake ring positioned to engage with said clutch shoe when the latter moves out of engagement with said clutch drum to provide for stopping the rotation of the spindle upon longitudinal movement thereof in said opposite direction.

ROBERT E. ALLEN.

WILLIAM F. UTZINGER.

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

UNITED STATES PATENTS Number Name Date 926,184 Hart June 29, 1909 1,122,206 Jennings Dec. 22, 1914 1,538,506 Arnold May 19, 1925 1,569,194 Long Jan. 12, 1926 2,291,629 Jackson et al Aug. 4, 1942 2,432,272 Barim Dec. 9, 1947

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