US1988895A

US1988895A - Device for dressing profiled grinding wheels

Info

Publication number: US1988895A
Application number: US687883A
Authority: US
Inventors: Godziewski Hermann
Original assignee: Herbert Lindner GmbH
Current assignee: Herbert Lindner GmbH
Priority date: 1933-05-23
Filing date: 1933-09-01
Publication date: 1935-01-22
Anticipated expiration: 1952-01-22

Description

Jan. 2.2, 1935. GoDzlEwsKl 1,988,895

DEVICE OR DRESSING PROILED GRINDING WHEELS Filed Sept. 1, 1955 3 Sheets-Sheet 2A Y l l A y l A A enna/1h Gola/bush' u. 7 Maw.:

l Jam 22, 189.35; H. GoDzu-:wsKl l .1,988,895

DEVICE FOR DRESSING-PROFILED GRINDING WHEELS Filed Sept. l, 1953 3 Sheets-Shea?l 3 Patented .lan. 22, 1935 UNITED STATE DEVICE ronV DRESSING PnomED GRINDTNG WHEELS Hermann Godziewski, Eichwalde,

assignor to Herbert m. b. H., Berlin-Witteman, Germany,

Germany,

corporation Application I Kreis Teltow, Lindner G. a limited September 1, 1933, Serial No. 687,883 n Germany May 23, 1933 11 claims. (c1.125'11) The two positions of the lever are limited by 6 the profile of the grinding wheel.

Means have previously been employed to dress profiled grinding wheels by a copying process in which a diamond controlled by means f a link parallelogram is employed. A dressing device has also already been employed comprising two slides mounted on a rotary axle, which are connected through a lever system with one another. ,The oneslide carries the dressing tool and the other a tracer which is guided over a former. The first mentioned devices can only be constructed in grinding machines in a complicated manner and require a comparatively large space. In the last mentioned device only a shaped diamond can be used, which operates with at least two corners and the intermediate edge of its prole. Apart from the fact that a shaped diamond is costly and less durable in use than a rough diamond, there are also difficulties in keeping the tracer always exactly in accord with the cutting edges of the dressing tool subjected to the wear.

The device according to the invention does not show these disadvantages. Its principal features are as follows:

Two dressing tools are secured side by side a predetermined distance apart on a two-armed lever, which dressing tools can be normal shaped diamondsy or grinding tools of very hard material. This double lever is movable about a rotary axis, which lies in a plane parallel to the axis of the grinding wheel, as well as about an axis perpendicular t-o the plane of the grinding wheel prole, and these movements are effected from lthe tracer guided over a former or pattern,l

the tracing arm turning its guide member t0- gether with the double lever connected therewith and the dressing tools and at the same time operating over suitable intermediate members, for instance a toothed rack and toothed wheel, a cam, which so operates on the double lever, that the dressing tools move in a radial direction to and from the grinding wheel. The double lever carrying the dressing tools is arranged, with the cam which controls its movement to and from the grinding Wheel, in a rotary shaft of the guide member of the tracing arm. In order, after the completion of one profile-half to bring the one dressing tool out of engagement with the grinding wheel and the other into operative position, the double lever is movable in the direction of its rotary axis. v v

means of stops, able. A spring-pressed lever against the operative stop.

shaft, on which the double s PATENT oFFicE of which at least one is adjustpin presses the double The rotary lever is mounted, projects from its bearing and is provided with two oblique surfaces, which tion of the tracer at the base move the shaft-with the axially in one or other In this way when the dressing of the stationary stops and lever and dressing tools direction.

abut in each end-posiof the former against one profile-half hasbeen completed, one dressing tool is automatically brought into and the other out of the operative position. The carrier for the dressing tools on the lever and in such a ting edge of a dressing position over the centre is movably arranged manner that the cuttool can be adjusted to a line of the prole to be produced. The whole device is arranged in a slide, which is adjustable in suitable guides with respect to the grinding wheel,

for location of the dressing tools and in order to allow for the decreasing diameter of the grinding wheel.

An embodiment of the invention is illustrated in the accompanying drawings, in which Figure 1 is a view in longitudinal section of the said embodiment,

Figure 2 is a plan view,

Figure 3 is a transverse I-I of Figure 1,

section on the line Figure 4 is a transverse section on the line II-II of Figure 3,

Figures 5 to 7 show the dressing tools in various operative positions, the arrangement here shown being that for the production of Whi for dressing a grinding wheel tworth threads.

Figure 8 shows the cam path of the guide cam for the tool lever.

Figure 9 is a plan view,

partly in section, of

the completedevice, its mounting and hood.

Figure 10 is an elevation,l

partly in section,

from the right side of Figure 9, the view being turned to erect position.

Referring now to the tools 1 and 2 are secured holder 3 mounted on one drawings, the dressing side by side in a tool end of a two-armed 5 is mounted in the

bearings

6 and 7 in a rotary hollow stub shaft 8' extending from the member 8. The axis y-y ofthe r otary shaft 8' is perpendicular to rthe plane of the profile of the grinding wheel S. It need not, as shown in the drawings, pass through the but can pass outside this.

axis of rotation :1r-x, The member 8 serves as a guide member for the tracing arm v9, which carries the tracing roller 11 guided over the former or pattern 10. The former 10 is secured on a slide 12, which is provided with a bearing for the rotary shaft 8. 'I'he tracing arm 9 has a toothed rack 9', which engages with a toothed wheel 13. With the toothed wheel 13 is connected a cam 14, which rotates with the toothed wheel on a shaft 15 arranged in the rotary shaft 8'. The lever 4 carries a lug 4' which is pressed continuously by a spring 16 against the cam 14. For effecting the rotation of the cam a steel band, rope or the like under tension, can also be secured to the tracing arm 9, so as to wind on or off a drum connected with the cam and so rotate the latter.

The distance measured from the point of contact of the tracer 11 with the former 10 to the axis y-y of the rotary shaft 8' bears a predetermined relation to the distance measured from the point of contact of the dressing tool 1 or 2 with the grinding wheel S to the axis y-y of the rotary shaft 8'. The throw of the cam 14, taking into account the proportion of the lever arms of the lever 4 to one another, is properly proportioned with respect to the length of the prole of the former 10.

If now the tracer 11 is guided along the former, then the tracing arm 9, through'the rack 9', the toothed wheel 13 and the cam 14, causes a movement of the lever 4, due to which that dressing tool situated in the operative position moves in a radial direction to or from the grinding wheel.

. At the same time, however, through the tracing arm 9, the guide member 8 and shaft 8', together with the lever 4 and the dressing tools is rotated around the axis y-y, so that the dressing i tool executes, corresponding to the proii'le angle of the former 10, a movement in the direction of the axis of the grinding wheel. In this way there is produced on the grinding wheel a prole,

which corresponds exactly with the former in a proportion corresponding to the transmission ratio of the elements transmitting the movements. The shape of the cam 14 is shown in Figure 8. The cam path begins at the point a and continues to the point b. The greatest elevation of the cam path corresponds, in the proportion of the transmission ratio to the height of the profile of the largest former for the largest grinding wheel proiile to be produced by I neans of the dressing device. The cam can, therefore, also be used for all smaller grinding wheel profiles. .The rack 9' then moves the cam, corresponding to the lower profile-height of the former, only through a fraction of the path a-b.

As already mentioned, only one dressing tool is in operative position at any time during the dressing process and shapes one half of the profile, while the other dressing tool is out of engagement with the grinding wheel. For this the two dressing tools 1 and 2 are arranged a distance A apart in the support 3. The space A is somewhat larger than the actual profile-base or' breadth of the grinding wheel. The dressing tools are so adjusted in the support 3 that their operative cutting-edges are the same distance from the axis matically eiiected since, as soon as the tracer 11 is guided over the respective end-position at the base of the profile of the former, an extension 5', projecting out of the bearing 6 of the shaft 5, engages with one or other of stop-surfaces 1'1 and 18 formed on said extension 5', in consequence of the rotary movement of the shaft 8' against one or other of

stops

19 and 20 and thereby causes the shaftl 5 to be shifted axially with the lever 4 and the dressing tools. 'Ihe stops 19 and 20 are secured to the part 12' of the slide 12. When the surface 1"I strikes against the stop 19 the lever 4 is moved with the shaft 5 into contact with the adjustable stop 21. the shaft 8 in the other direction, the stop-surface 18 strikes against the stop 20, and the shaft 5 with the lever 4 is moved to engage the stationary stop surface 22. 'I'he dressing tools 1 and lever 4 and in such a manner that the cuttingl.

edges of each dressing tool can be adjusted exactly to a position over the centre line of the prole to be produced. For the adjustment of the carrier 3 two screw bolts 30 and 31 are used which are secured to the lever 4 in a suitable manner.

The slide 12, which serves for the reception of the whole dressing device and the former, is movable in vsuitable guides in the particularly rigidly constructed protecting cover 27 for the grinding wheel S. It can, by means of the screw-spindle 28 which co-operates with a nut 29, be adjusted with respect to the grinding wheel. The screw spindle 28 can thereby be so connected with the screw spindle for the adjustment of the grinding wheel support that the grinding wheel is automatically re-adjusted with respect to the work by the amount of the dressing, lso that after the dressing of the grinding wheel the latter can be operated again without measurement being required.

Arranged in the upper part of the grinding wheel support 27' is the adjusting spindle 36 for adjusting' the grinding wheel support and the dressing device. Mounted upon the adjusting spindle 36 is a worm 37 engaging a worm wheel 38. The worm wheel shaft 39 is journaled in the grinding wheel support 27' and carries at its lower end a toothed pinion 40 `engaging a rack 4l fixed to the stationary base 41 of the machine. Mounted upon the rear end of the adjusting spindle 36 is a gear 42 driving a gear 44 by means of an idler gear 43. The'gear 44 is mounted upon the adjusting screw spindle 28 for the dressing device. Gear 44 drives the ad justing spindle 28 by means of a friction clutch 45. 'I'he clutch member 45' is longitudinally displaceable along the spindle 28 by means of a wedge 46. The adjusting nut 47, upon being tightened, presses thehand wheel 48 upon the clutch member 45', thereby clutching the gear 44 to the adjusting spindle 28. The transmission of motion from the adjusting spindle 38' Upon rotation of vmeans of the worm gear protecting cover or hood, is the dressing device."

When dressing of the grinding wheel S becomes necessary, the grinding wheel S is moved out lof engagement with the work piece W whereupon the handwheel 49 is turned to an extent indicated upon the scale 49 by the pointer 50. In this way. an adjustment of the grinding wheel support 27 toward the work piece is effected by gearing and rack and pinion 40, 41.

At the same time the dressing device is advanced `in its guideways (by means of the gears 42, 43, 44) toward the grinding wheel S for the same extent.- In other words, the grinding wheel is automatically adjusted with respect to the work piece for wearpcaused through the grinding and for the extent desired for dressing. Therefore, after the dressing has taken place no further correction is necessary in the radial adjustment of the effective grinding wheel profile with respect to the work piece W and grinding can be continued without prior testing.

If a grinding wheel of a different diameter is to be mounted on the grinding spindle, the adjusting means for the dressing device have to be disengaged from the Amain adjusting spindle 36. For this purpose, the gear -44 is moved-out of engagement with the spindle 28 through loosening of the adjusting nut 47 and of the friction clutch 45, 45', whereupon the dressing device is adjusted with respect to the grinding wheel S by means of the hand wheel.

The dressing device according to the invention can also be furnished with a single dressing tool which shapes the grinding wheel prole to be produced by two corners and the intermediate edge of its profil For this the stops 19 and 20 are removed and the adjustable stop screw 21 so screwed against the shaft that the lever 4 lis immovable in the direction of its rotary axis.

The use of two dressing tools is, however, preferred as in this case the disadvantages mentioned hereinbefore-shaping of the tracerare avoided, andonly a simple cylindrical tracing roller is required.`

The dressing device illustrated in Figures 1 to 8 may, if desired, be adapted for use with a single dressing tool. For this the stops 19 and 20 are removed and the adjustable stop screw 21 so screwed againstthe shaft 5 that the lever 4 is immovable in the direction of its rotary axis.

All shapes of grinding wheels can be dressed with the device constructed in accordance with the invention.

1. A device for dressing profiled grinding wheels, comprising two dressing tools controlled by means of a lformer and of which each, operates on a respective half of the grinding wheel profile, in which the dressing tools are mounted side by side on a two-armed lever adapted to turn about an axis of rotation which is in a plane parallel to the axis of the grinding wheel and also about an axis perpendicular to the plane Vof the grinding wheel profile, the turning move-f ments of the lever being effected by a tracer guided over a former, the tracing arm causing its guide member and a rotary shaft connected therewith to rotate together with the lever and dressing tools and at the same time operates, through the intermediary of suitable members, for example a toothed rack and toothed wheel, a cam which acts on the lever in such a manner asto cause the dressing tools to move radially with respect to the grinding wheel.

37, 38, and the toothed l 2. A device as claimed in claim 1, in which the double lever carrying the dressing tools is arranged, with the cam controlling its movement to and from the grinding wheel, in the rotary shaft of the guide member for the tracing arm.

3. A device as claimed in claim 1, in which the double lever is movable in the direction of its rotary axis in order that when onehalf of the profile has been dressed the one dressing tool may be brought out of engagement with the grinding wheel and the other brought into operative position.

4. A device for dressing profiled grinding wheels, comprising a support, a former pattern mounted thereon, a grinding wheel spindle mounted to revolve on a fixed axis, a shaft mounted in said support to rotate on an axis perpendicular to the periphery of a grinding wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular to the shaft, grinding wheel dressing means carried by one end of said lever to engage the periphery of a grinding wheel mounted on said spindle, and guide means for rotating said shaft on its axis and swinging said lever and including means to engage the former pattern.

5. A device for dressing profiled grinding wheels comprising a support, a former pattern mounted thereon, a grinding wheel spindle mounted to revolve on a xed axis, a shaft mounted in said support to rotate on an axis perpendicular to the periphery of a grinding wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular to the shaft, grinding wheel dressing means carried by one end of said lever to engage the periphery of a grinding Wheel mounted on said spindle, a head on said shaft, a guide bar slidably mounted in said head to reciprocate transversely of the shaft and having means on its outer end to engage the former pattern, and means connecting the bar and lever to oscillate the lever as the bar is protracted and retracted.

6. A device for dressing profiled grinding wheels comprising a support, a former pattern mounted thereon, a grinding wheel spindle mounted to revolve on a fixed axis, a shaft mounted in said support to rotate on an axis perpendicular to the periphery of a grinding Wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular to the shaft, grinding wheel dressing means carried by one en'd of said lever to engage the periphery of a grinding wheel mounted on said spindle, a head on said shaft, a guide bar slidably mounted in said head to reciprocate transversely of the shaft and having means on its outer end to engage the former pattern, means connecting the bar and lever to oscillate the lever as the bar is protracted and retracted, stops limiting the movement of oscillation of said lever and means to adjust the position of at least one of said stops.

7. A device for dressing profiled grinding wheels comprising a support, a former pattern mounted thereon, a grinding wheel spindle mounted to revolve on a fixed axis, a shaft mounted in said support to rotate on an axis perpendicular to the periphery of a grinding Wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular to the shaft, grinding wheel dressing means carried by one end of said lever to engage the periphery of a grinding Wheel mounted on said spindle, a head on said shaft, a guide bar slidably mounted in said head to reciprocate transversely of the shaft and having means on its outer end to engage the former pattern, means connecting the bar and lever to oscillate the lever as the bar is protracted and retracted, stops limiting the movement of oscillation of said lever, means to adjust the position of at least one of said stops, and a spring holding said lever against the adjustable stop.

8. A device for dressing proled grinding wheels comprising a support, a former pattern mounted thereon, a grinding Wheel spindle mounted to revolve on a fixed axis, a shaft mounted in said support to rotate on an axis'perpendicular to the periphery of a grinding wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular to the shaft, grinding wheel dressing means carried by one end of said lever to engage the periphery of a grinding wheel mounted on said' spindle, guide means for rotating said shaft on its axis and swinging said lever and including means to engage the former pattern, a base whereon said support is slidably mounted to move toward and from the axis of said spindle, and means to move the support and the parts carried thereby toward and from said spindle.

9. A device for dressing profiled grinding wheels comprising a support, a former pattern mounted thereon, a grinding wheel spindle mounted to revolve on a fixed axis, a shaft mounted in said support to rotate on an axis perpendicular to the periphery of a grinding wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular to the shaft, grinding wheel dressing means carried by one end of said lever to engage the periphery of a grinding wheel mounted on said spindle, a head on said shaft, a guide bar slidably mounted in said head to reciprocate transversely of the shaft and having means on its outer end to engage the former pattern, means connecting the bar and lever to oscillate the lever as the bar is protracted and retracted, a base whereon said support is slidably mounted to move toward and from the axis of the said spindle, and means to move the support and the parts carried thereby toward and from said spindle.

10. A device for dressing profiled grinding wheels comprising a support, a former pattern mounted thereon, a grinding wheel'spindle mounted to revolve on a fixed axis, a shaft lmounted in said support to rotate on an axis perpendicular tothe periphery of a grinding wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular tothe shaft, grinding wheel dressing means carried by one end of said lever to engage the periphery of a grinding wheel mounted on said spindle, a head on said shaft, a guide bar slidably mounted in said head to reciprocate transversely of the shaft and having means on its outer end to engage the former pattern, means connecting the 'bar and lever to oscillate the lever as the bar is protracted and retracted, stops limiting the movement of oscillation of said lever, means to adjust the position of at least one of said stops, a base whereon said support is slidably mounted to move toward and from the axis of said spindle,

and means to move the support and the parts carried thereby toward and from said spindle.

11. A device for dressing profiled grinding wheels comprising a support, a former pattern mounted thereon, a grinding wheel spindle mounted to revolve on axed axis, ashaft mounted in said support to rotate on an axis perpen-' dicular to the periphery of a. grinding wheel on said spindle, a lever pivoted intermediate its ends to said shaft to swing about an axis perpendicular to the shaft, grinding wheel dressing means car- 'ried by one end of said lever to engage the pe' riphery of a grinding wheel mounted on said spindle, a head on said shaft, a guide bar slidably mounted in said head to reciprocate transversely of the shaft and having means on its outer end to engage the former pattern, means connecting the bar and lever to oscillate the lever as the bar is protracted and retracted, stops `limiting the movement of oscillation of said lever, means to adjust the position of at least one of said stops, a spring holding said lever against the adjustable stop, a base whereon said support is slidably mounted to move toward and from the axis of said spindle, and means to move the support and the parts carried thereby toward and from said spindle.

HERMANN GODZIEWSKI.