US2205009A

US2205009A - Edge grinding apparatus

Info

Publication number: US2205009A
Application number: US225500A
Authority: US
Inventors: Henry J Hamann; Jr Carl B Williams
Original assignee: Libbey Owens Ford Glass Co
Current assignee: Libbey Owens Ford Glass Co
Priority date: 1938-08-18
Filing date: 1938-08-18
Publication date: 1940-06-18
Anticipated expiration: 1957-06-18

Description

Fame 18, J HAMANN m AL 2,2@5,@9

EDGE GRINDING APPARATUS Filed Aug. 18, 1958 3 Sheets-Sheet 1 Summers HENEY d. HAM/INN CARL 5. WILLIAMS UK.

June 18, 1 0- H. J.-HAMANN ET AL 3 ,0

EDGE GRINDING APPARATUS Filed Aug. 18, 1938 3 Sheets-Sheet 2 Juventors .--W HENAY d. HHMANN CARL B. WILLIAMS Q/K.

attorney H. .1. HAMANN ET AL 3 ,0

EDGE GRINDING APPARATUS Filed Aug. 18, 1938 3 Sheets-Sheet 5 Inventors HENRY cl. H/JMANN CAP]. .5. W/LL/AM5 dfi Gttorncg Patented June 18, 1940 UNITED STATES Mam" orrrce EDGE GRINDING APPARATUS Ohio Application August 18,

8 Claims.

The present invention relates broadly to grinding machines and more particularly to improved apparatus for treating the edges of sheets or plates of glass and the like.

.5 An object of this invention resides in the provision of grinding apparatus of relatively simplified and inexpensive construction particularly adapted for rounding the relatively sharp corners of sheets or plates of glass which are to be used as door and window lights in automative vehicles, although it is of course in no way restricted to such use.

Another object of the invention is the provision of grinding apparatus of the above character which will round and finish the corners of the glass sheets or plates rapidly, accurately, and economically with a minimum amount of handling and also with a minimum amount of effort and attention on the part of the operator, where- 20, by uniformly rounded corners with well finished surfaces may be secured.

Another object of the invention is the provision of grinding apparatus of the above character embodying a vertical grinding wheel rotatable about 25 a substantially horizontal axis, a work holder rockably mounted above the grinding wheel for Supporting the glass sheets to be ground on edge in a substantially vertical position, and means for rocking said work holder first in one direction and then the other and for automatically varying the speed or rocking movement of the said work holder when it reaches predetermined positions to obtain a more eflicient, uniform grinding of the sheet edges.

Another object of the invention is the provision of means for rocking the work holder in a manner to cause the same to move at a predetermined speed at the beginning and end of its rocking movement in either direction and to automatically slow down during the intermediate period of its rocking movement so as to obtain a more intensive grinding action at the corners of the glass sheets where the maximum amount of material must be removed to effect the desired rounding thereof.

A further object of the invention is the provision of means associated with the drive means for thework holder which will effect a more steady, even and uniform rocking movement thereof as 50 Well as causing it to be brought to an abrupt stop immediately upon a shutting off of the driving power.

A still further object of the invention is the provision of means associated with the work holder for facilitating the removal of the glass Williams, Jr., to Libbey-Owens-Ford Ohio, a corporation of 1938, Serial No. 225,500

sheets therefrom upon the completion of the grinding operation.

Other objects and advantages of the invention will become more apparent during the course of the following description, when taken in connec- .5. tion with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

Fig. 1 is a side elevation of grinding apparatus 10 constructed in accordance with the invention;

Fig. 2 is a vertical section through the drive means for the work holder taken substantially on line 22 of Fig. 1;

Fig. 3 is a longitudinal vertical section through the work holder;

Fig. 4 is a vertical section taken substantially on line 6-4 of Fig. 3; a

Fig. 5 is a horizontal detail section taken substantially on line 5-5 of Fig. 3;

Fig. 6 is a horizontal detail section of the drive means for the work holder taken substantially on line 6-6 of Fig. 2;

Fig. '7 is a section through the friction brake means associated with the drive shaft taken substantially on line 'l--l of Fig. 2;

Fig. 8 shows a glass sheet having a relatively sharp corner to be rounded; and

Fig. 9 shows the sheet after being ground.

Referring now to the drawings, the grinding apparatus comprises a suitable supporting framework IO carrying at its upper end a horizontal channel member H comprising a bottom l2 and vertical side walls l3 and i4. Also mounted upon the supporting frame work H3 is a vertically disposed grinding wheel I5 rotatable about a substantially horizontal axis. The lower portion of the grinding wheel operates within a receptacle l6 containing a suitable abrasive material, while the upper portion of said wheel projects upwardly through a slot ll formed in the bottom l2 of channel member I l as best shown in Fig. 3.. Supported Within the channel member l l, to one side of the grinding wheel, is a channel iron 18 carrying a plurality of freely rotatable horizontally aligned conveyor rollers l9 over which the glass sheets may be moved to grinding position.

Mounted above the grinding wheel I5 is the work holder 20 adapted to support one or a plurality of glass sheets ill to be treated. The work holder 20 comprises the two spaced parallel, substantially L-

shaped side members

22 and 23, each having a substantially vertical leg 24 and a substantially horizontal and relatively longer leg 25. Extending between and carried by the horizontal 55 legs 25 of the side members are a plurality of transverse pins 26 carrying the freely rotatable rollers 2'! preferably grooved and adapted to receive the bottom edges 28 of the glass sheets 21 therein. Carried by and extending between the vertical legs 2d of said side members are one or more transverse pins 25 carrying freely rotatable grooved rollers adapted to receive the inner edges .ii of the glass sheets 2!. The vertical legs 25 of the

opposite side members

22 and 23 of the work holder can be secured together at their outer ends by a transverse angle iron 32, while the hori zontal legs 25 can be connected together at their outer ends by a similar angle iron Carried by the opposed vertical legs 24 of the side members and 23, adjacent the outer ends thereof, are the substantially horizontal bracket arms 3-"?- and 35 connected together at their outer ends by a transverse angle iron 36. Extending between and carried by the bracket arms 34- and 35 are the transverse pins 3'! carrying the freely rotatable grooved rollers 38 adapted to receive the upper edges 39 of the glass sheets 2! The bracket arms 3d and 35 are adjustably secured to the side members and N. by means of bolts 50 passing through vertical slots ii in said bracket arms whereby they may be raised or lowered to take care 05 glass sheets of different widths.

The work holder 28 is rockably mounted upon the channel member if and to this end, there is provided at substantially the juncture of the vertical and

horizontal legs

26 and 25 the outwardly projecting trunnions E2 and 43 which are loosely received within vertical slots M5 and 45 in the side walls i3 and i l respectively of said channel member. The

trunnions

42 and 43 may be held against vertical movement within said slots by metal strips 55 and 4-! secured to the vertical side walls l3 and M of channel member II.

The

side members

22 and 23 of work holder 26 may also be braced by the angle straps 48 secured to the vertical and

horizontal legs

24 and 25. Pivotally connected to said straps, intermediate the ends thereof, as at 1-9, are the substantially

horizontal arms

50 and 5|, said arms being connected together at their outer ends by a cross member 52 formed with a threaded socket Threaded within the socket 53 is one end of a connecting rod 54 pivoted at its outer end as at 55 to the upper end of the vertical arm 53 of a bell-crank lever 57. The bell-crank lever 51 also has a substantially horizontal and relatively shorter arm 58 and is pivoted as at 59 to a bracket 58 carried by a supporting frame 6|.

The means for rocking the bell-crank lever 5? to effect substantially horizontal reciprocating movement of the connecting rod 54 to cause rocking movement of the work holder 20 upon

trunnions

12 and 33 comprises a rotatable cam said cam being disposed in a vertical position and mounted upon a horizontal shaft 63 supported in a bearing 64 and driven from any suitable source of power such as an electric motor, not shown. The cam 62 has formed upon its outer face a continuous groove 65 of the desired shape and loosely received within said groove is a roller 68 carried at the lower end of a vertical slide block This slide block is mounted for vertical sliding movement in a guideway 58 provided in a channel member 69 secured to the supporting frame 3!. Carried by the slide block 6?, adjacent its upper end, is a pin "iii to which is pivoted one end of a vertical link pivotally connected at its upper end, as at l 2, to the arm 58 of bell-crank lever 57.

In the operation of the apparatus, the work holder 20 is first swung to the position shown in full lines in Fig. l at which time the rollers 21 thereof are in horizontal alignment with conveyor rollers i9 so that the glass sheets 2| to be treated can be moved horizontally over rollers i9 and 21 into the work holder and until the inner edges 35 thereof abut rollers 39. During the positioning of the glass sheets in the work holder, the cam 62 and its associated parts, including the roller 56, will also be in the positions indicated in Figs. 1 and 2. After the glass sheets have been properly positioned in the work holder 20, the drive shaft 63 is rotated to turn the cam 82 in a counter-clockwise direction as viewed in Fig. 1, whereupon the roller 66 running in the groove 65 of said cam will draw the slide block 6'! downwardly. This will cause the bell-crank lever 57 to be rocked in a clockwise direction to swing the work holder 20 upon trunnions 52 and 43 also in a clockwise direction to move the lower inner corners of the glass sheets indicated at a. in Fig. 8 over and in engagementwlth the grinding wheel IS. The groove 65 in cam 62 is so shaped that after the work holder has been turned approximately degrees, the slide block 5? will be moved upwardly to rock the bell-crank lever 5'! in a counter-clockwise direction to return the Work holder to its original starting position. During the return movement of the work holder, the corners a of the glass sheets will also engage the grinding wheel. Ordinarily, the rocking of the glass sheets first in one direction and then back to starting position will be sufiicient to properly grind the relatively sharp corners a of the said sheets so that they will be rounded as indicated at b in Fig. 9. The periphery of the grinding wheel l5 may be flat as shown or it may be provided with plurality of circumferential grooves to form a so-called pencil edge on the glass sheets.

In order to properly round the square corners a (Fig. 8) of the glass sheets, it is desirable that the speed of rocking movement of the work holder 29 be reduced during an intermediate period of the grinding operation so that a more intensive grinding of the corners can be obtained where the greatest amount of glass must be removed. Therefore, according to the invention, the groove 65 in cam 62 is so shaped that as the glass sheets 2| are rocked in a clockwise direction, the work holder 26 will move at a predetermined speed until the bottom edges 28 of the glass sheets are disposed substantially at an angle represented by the line 0 in Fig. 8. At this time, the speed of rocking movement of the work holder will be increased to its original speed and this movement continued throughout the remainder of its travel. Upon the return of the work holder to its starting position, it will travel at the relatively higher speed until the edges 28 of the glass sheets are disposed at the angle represented substantially by the line d, whereupon the speed of movement of the work holder will be reduced until the edges 23 are disposed at the angle represented substantially by the line 0 at which time its speed of movement will again be increased and continued throughout the balance of the rocking movement of the work holder. By reducing the speed of rocking movement of the work holder in this manner, it will be apparent that more time will be allowed for grinding those portions of the corners where the largest amount of material must be removed.

With the form of cam shown in Fig. l, the work holder 20 will travel at its higher rate of speed during the movement of the roller 66 from the position therein shown to the point A in groove 65 while during the travel of the roller from point A to point B the speed of rocking movement of the work holder will be reduced. As the roller 66 travels from point B to point C the speed of movement of the work holder will again be increased and when the roller 66 reaches point C in groove 65 the work holder will have been turned in a clockwise direction approximately 90 degrees. As the roller 66 travels from point C to point D the work holder will be rocked in a counter-clockwise direction at its higher speed whereas its speed of movement will be slowed down as the roller travels from point D to point E and then again increased upon travel of said roller from point E back to theposition shown in Fig. 1.

When the work holder 20 reaches the end of its return movement, it is adapted to actuate a limit switch 13 to automatically shut oil the motor driving the shaft 63. It is desirable to bring the drive shaft 63 to an abrupt stop upon shutting off of the driving power thereto whereby to prevent any further movement of the Work holder. For this purpose, there is associated with the drive shaft 63 a friction brake designated in its entirety by the numeral M. As best shown in Fig. 7, the shaft 63 has keyed thereto a brake drum 15, while encircling said drum are the two semi-circular brake shoes Hi and 11 hinged together at one end as at 78 upon a fixed bracket '19. Also encircling the brake drum [5 within brake shoes 16 and 11 is the brake lining 8B. The outer ends of the brake shoes 16 and IT are provided with spaced ears BI and 82 respectively and passing therethrough is an adjusting bolt 83 having a nut 84 threaded upon one end and a spring 85 encircling the opposite end outwardly of 81, said spring 85 normally urging the brake shoes towards one another and into engagement with the brake drum. Upon rotation of the bolt 83, the pressure exerted by the brake shoes upon the drum may be varied as desired. In addition to bringing the shaft 63 to an abrupt stop upon shutting off of the motor which drives the same, the friction brake 14 also causes the shaft 63 and consequently the work holder to have a more steady movement with less vibration which will result in a more even, uniform grinding of the sheet edges.

The invention also includes means for facilitating the removal of the glass sheets 25 from the work holder 20 upon completion of the grinding thereof. This means includes a pair of arms 86 and 8'! arranged outwardly of the

side members

22 and 23 of the work holder and pivotally mounted at their inner ends upon the reduced

inner end portions

88 and 89 of the

trunnions

42 and 43 respectively. The arms 86 and 81 are connected together at their outer ends by the transverse member 90 which forms a hand-grip for the operator to facilitate swinging movement of said arms upon said trunnions. Carried by the arms 85 and 81 intermediate the opposite ends thereof are the bracket plates 9| and 92 respectively and arranged between and carried by said bracket plates is a roller 93. This roller is adapted, during the grinding of the glass sheets, to be received between the side members of the work holder and engageable by the inner edges 3| of the glass sheets. As best shown in Fig. 5, the bracket plates 9| and 92 are received within the vertical legs '24 of the

side members

22 and 23 of the work holder and are adapted to frictionally engage the inner surfaces of the said legs and held thereby in position until manually disengaged therefrom by the operator. As before stated, during the grinding of the glass sheets, the roller 93 engages the inner edges of the glass sheets as shown in full lines in. Fig. 3 at which time the arms 86 and 81 will be in the the dotted line position. After the grinding operation has been completed and it is desired to remove the glass sheets from the work holder, the operator simply grasps the transverse member 963 and pushes the same rearwardly thereby swinging the arms 86 and 8'5 forwardly to the position indicated by the dot and dash lines in Fig. 3. As the arms are swung forwardly to this position, the roller 93, engaging the inner edgesof the glass sheets, will shove the sheets rearwardly to partially eject them from the work holder and into a position Where they can be more readily removed from the work holder by the operator.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

We claim:

1. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the like, a rotary grinding wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, and means for rocking said work holder first in one direction and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel, said means including means for causing said work holder to travel relatively fast at the beginning and end of its rocking movement and relatively slower during the intermediate period of its rocking movement.

2. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the like, a rotary grinding Wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, and means for rocking said work holder first in one direction and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel, said means including cam means for causing said work holder to travel relatively fast at the beginning and end of its rocking movement and relatively slower during the intermediate period of its rocking movement.

3. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the like, a rotary grinding wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, and means for rocking said work holder first in one direc tion and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel, said means including rotatable cam means constructed to cause said work holder to travel relatively fast at the beginning and end of its rocking movement and relatively slower during the intermediate period of its rocln'ng movement.

l. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the like, a rotary grinding Wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, means for rocking said work holder first in one direction and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel including a drive shaft, a cam carrier thereby, operative drive connections between said cam and work holder, said cam being constructed to cause said work holder to travel relatively fast at the beginning and end of its rocking movement and relatively slower during the intermediate period of its rocking movement, and braking means associated with said drive shaft for bringing the same to an abrupt stop upon shutting off of the driving power thereto.

5. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the like, a rotary grinding wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, means for rocking said work holder first in one direction and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel, and means carried by said work holder and adapted to be manually actuated upon completion of the grinding operation for ejecting the glass sheet from the said work holder.

6. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the ke, a rotary grinding wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, means for rocking said work holder first in one direction and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel, a rockably mounted arm carried by said Work holder, and a roller carried by said arm engaging the inner edge of the glass sheet and adapted upon rocking of the said arm upon completion of the grinding operation to eject the glass sheet from the said work holder.

7. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the like, a rotary grinding wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, means for rocking said work holder first in one direction and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel, and means pivotally carried by said Work holder and adapted to be actuated upon completion of the grinding operation for ejecting the glass sheet from the said work holder.

8. An apparatus for rounding the relatively sharp corner of a sheet or plate of glass or the like, a rotary grinding wheel positioned to rotate about a substantially horizontal axis, a work holder mounted above the grinding wheel for supporting the sheet to be ground on edge in a substantially vertical position, means for rocking said work holder first in one direction and then the other to move the corner of the sheet to be rounded over and in engagement with said grinding wheel, a pair of arms pivotally carried by said work holder, and a member arranged between and carried by said arms engaging the inner edge of the glass sheet and adapted upon rocking of the said arms upon completion. of the grinding operation to eject the glass sheet from the said work holder.

HENRY J. HAMANN. CARL B. WILLIAMS, J a.