US1516895A - Speed-changing device for grinding wheels - Google Patents

Description

P. STONER SPEED CHANGING DEVICE FOR GRINDING WHEELS Nom 25, 1924. 1,516,895

Nov. 25, 1924 .1,516,895

P. sToNER SPEED CHANGING DEVICE FOR GRINDING WHEELS' Filed Nov. 18, 1920 3 shuts-sneet 2.

Patented Nov. 25, 1924.

UNITED STATES PATENT OFFICE.

A' PAUL-STONER, 0F WAYNESBORO, PENNSYLTTANIA, ASSIGNOR TO LANDIS TOOL COM- PANY, OF WAYNEISBORO, PENNSYLVANIA, A CORPORATION F PENNSYLVANIA.

SPEED-CHANGING DEVICE FOR GRINDING WHEELS.

Application led November 1,8, 1920. Serial No. 424,902.

To all whom t may concern:

Be it known that I, PAUL STONER, a citizen of the United States, residing at Waynesboro, in the county' of- Franklin and State of Pennsylvania, have invented certain new and useful Improvements in Speed- Changing Devices for Grinding Wheels,` of

which the following is a specification. l

My invention relates to a speed changing device for grinding wheels and provides means whereby the grinding wheel may be driven ata relatively lowy axial speed when first used, and atan increased speed when the wheel has becomev worn down. l

Une object of my invention is to `.provide 4the wheel spindle with a telescoping pulley adapted to run the spindle at different speeds, simple means being provided for changing from low to high speed.

Another object is to provide a safety device whereby the operator is prevented from driving a full sized .wheel at high speed. Referring to the accompanying drawings which are made a part hereof and on which .3 similar reference characters indicate similar parts,

Fi ure 1 is a side elevation of a wheel spin le constructed in accordance with my invention with the telescoping pulley shown in section;

Iigure 2, a plan view thereof with the casing broken away;

Figure 3, a section on line 3x3 of Figure 2; and 'x Figure 4, a detail section of the spindle.

In Figure-1, A represents the grinding wheel which is shown as having been worn down far enough to permit it to be operated at high speed without danger of breakage due to centrifugal force. A shield surrounding the said wheel is indicated at B and is adapted to be moved back as the wheel wears away, being secured in place by a clamp or the like after such' adjustment. A casing C encloses the telescoping pulley, and its associated parts. K

The spindle has mounted thereon a cylindrical belt receivin member 11 which is made secure vthereto y means of a set screw 12 entering an aperture 13` in the spindle. This member 11 4is crowned adjacent to one end, thus forming a pulley V14 to receive a belt 15 for imparting rotary motion thereto, while at the opposite end it is adapted toreceive a sleeve' 16 splined thereto at 17 and crowned as atl 18 to receive the belt 15 which climbs the inclined portion 19 when thel sleeve is moved to over- 1e the pulley 14, as shown in Figure 4, andI so imparts a slower speed to the spindle 10 and grinding wheel A. The sleeve 16 is also provided with an annular flange 20 which is spanned b from a rack bar'` 22 s idably mounted within the casing C. The teeth of the rack bar mesh with those ofa segment 24 fastened to a vertical spindle 25 which is squared at its upper end as at 26 for the reception of a wrench or an operating handle of any suitable form. The spindle 25 is also provided adjacent the segment with a pinion 27 meshing with'the teeth 28 of a safety locking` bar 29 designed to strike against `a lug 29 on the shield B should the attendant attempt to operate a full sized wheely at the higher speed. y v

The casing C or a movable portion thereof is provided with two depending lugs 30 which confine the belt bot-h during the operation of changing-the pulleys from the high to the low speed, and vice versa.

s Located within the cylindrical member 1l a yoke 21 depending.

is a yieldable detent 31 designed to enter the `annular groove 32 in sleeve 16 when the pul- -leys are set for high speed and to enter the similar Groove 33 when in the low speed position. tPins 34 scured to the machine frame or to the floor of the building are shown as passing through slots 35 to provide one couventional means for adjustment of the casing B.

The operation of the device is as follows:

When the wheel A is of full size, it is not desired to have it travel at a very high speed owing to the centrifugal force created therein, therefore when a large size wheelA is in position, the shield B carrying the lug 29al is in a forward position which places the lug 29 in line with the safety b-ar 29. This prevents the shifting of the pulley sleeve 15 from. the .position shown in higure 4, so that there is little or .no danger of damage to the wheel A by reason of excessive speed. W'hen the grinding Wheel has become worn sutliciently the shield B must be moved back to allow the Vwork to contact with wheel A.

rl`he lug 29a is now out of the path of the yond the lug- 29a and at the same time causes the withdrawal of the sleeve 16 to the position shown in Figures 1 and 2, which permits the belt to run on the smaller pulley 14 and impart a high speed to the wheel.

II do not` ropose to limit myself to the specific detalls shown and described, nor to the particular useI have made of my device, as it will be found useful in other relations and in various modified forms such as will occur to those skilled in the art. The scope `Of my claims.

Having thus fully described my said invention, what I claim as new and des-ire to secure by Letters Paent is:

1. In a grinding machine, a spindle, a

` grinding wheel secured thereto, a shield for the wheel, variable speeddriving means on the Spindle, and means on the shield for controlling the operation of the speed varying means.

2. In a grinding machine, a grinding wheel, a speed changing driving means for the wheel, a rod moved by the changespeeddevices, a shield for the wheel, and

a lug on the shield in position to prevent movement of the rod the shield being adapted to be moved back as the wheel wears Aand thus move the lug out of the path of the rod.

,3. In combination, an expansible pulley comprisingsa belt receiving member and 'a belt receiving sleeve adapted to encircle the same or be withdrawn therefrom, a shaft adjacent the sleeve, connecting means between the shaft and the sleeve, a shield for the grinding wheel adapted to be moved as the wheel wears away, and means connected to the shaft and restrained from movement by the shield in its first position, whereby movement of the sleeve is prevented.

4. In combination, a grinding wheel, driv- ,ing means therefor comprising a pulley, an

expansion sleeve for the same, and means to move the sleeve to encircle the pulley com rising a yshaft extending transversel to t e pulley and adapted to be rotate connecting means between the shaft and the sleeve, va slidable rod connectedto the shaft, anda shield for the wheel having a portion normally in position to prevent movement of the rod, but adapted to be moved out of its path as the wheel diminishes in size.

5. In a grinding machine, la casin a shafttherein, a belt pulley on the sha a sleeve at one end of the pulley adapted to slide underthe belt to change the speed of invention is shown by the appended'- wheel, change-Spee the shaft, a slidable toothed shifter bar for the belt, a second toothed slidable bar projecting at one end from the casing, a shaft having a squared head projecting from the casing, rack segments on the shaft engaging said toothed` bars, and means outside. the casing adapted to en age the second barto` prevent operation of the speed changing means, substantially as set forth.

6. The combination of an abra-ding device, means for driving the same, speed changing means. including a movable element, and means to prevent'increase of speed of the abrading device until the same has worn down toa predetermined extent said lastnamed means including an obstruction directly in the path of said element of the speed-changing means, substantially as set 7 The combination of a. rotary grinding wheel, speed-changing driving means therefor including a reciprocatory part, and means to prevent change to higher speed including an obstruction maintained directly in the way lofthe-reciprocatory part by said wheel so long as the wheel is above a predetermined diameter.

8. In a grindin machine, a grinding wheel, change-Spee driving means for the, wheel, a rod positioned to be moved by said means in their speed-chan ing movement, and a shield for the wheeI adapted to be positioned to either prevent or permit move- 'ment of said rod, substantially as set forth.

9. In a grindin machine, a `grinding driving means for the wheel, a rod positioned to be moved by said means in their speed-changing movement, and a stop for the wheel adapted to be posi'- tioned to either prevent on permit movement of said rod aecordin to the size of the wheel, substantially as setv orth.

10. In a grindin machine, a grinding wheel, a spindle or driving, it, speedchanging driving means for the spindle, and a shield for the grinding wheel adjustable to permit or prevent speed-changing movement of said means according to the size of the wheel, substantiallyias set forth.

In witness whereof, I have hereunto set my hand and seal at Washington, District of Columbia, this thirteenth da of November, A. D. nineteen hundred an l twenty.

y fiumiJ s'roNER.

Witnesses: I'

E. W. BRADFORD, F. W. DAnN.

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