US2558943A

US2558943A - Bar grinding apparatus

Info

Publication number: US2558943A
Application number: US127484A
Authority: US
Inventors: Ellison Stanley Russell
Original assignee: Wilbur B Driver Co
Current assignee: WILBUR B DRIVER CO
Priority date: 1949-11-15
Filing date: 1949-11-15
Publication date: 1951-07-03
Anticipated expiration: 1968-07-03
Also published as: GB684376A

Description

July 3, 1951 s. R. ELLISON BAR GRINDING APPARATUS 3 Sheets-Sheet 1 Filed NOV. 15. 1949 R 4/ mm/ mm Vu i R H w n 0/ f S B I t: .1.

ATTORNEY July 3, 1951 s. R. ELLISON BAR GRINDING APPARATUS 5 Sheets-Sheet 2 Filed Nov. 15; 1949 INVENTOR.

Stanley R. Ellison ATTORNEY Patented July 3, 1951 BAR GRINDING APPARATUS Stanley Russell Ellison, Short Hills, N. J assignor to Wilbur B. Driver Company, Newark, N. 3., a corporation of New Jersey Application November 15, 1949, Serial No. 127,484

6 Claims.

This invention relates to bar grinding apparatus and is an improvement of the bar grinder apparatus described and claimed in Platt Patents Nos. 2,347,503 and 2,347,639, both issued on April 25, 1944, which patents are assigned to the same assignee as the present application.

She object of the present invention is to provide an improved means for controlling or regulating the grinding wheel pressure on the surface of the axially moving and rotating bar in the bar grinder device of said Platt patents thereby to control or regulate with greater certainty the depth of grinding out.

Another object is to provide a means for automatically varying the grinding wheel pressure as the contour of the rotating bar varies.

Still another object is to provide an improved bar grinder device of the type disclosed and claimed in said Flatt patents which is adapted to surface grind bars of different cross-section, such as round, square, hexagonal, etc.

A further object is to provide a pneumatic actuated means under the control of an electromechanical control means for varying the grinding wheel pressure in the said Platt device to thereby maintain a uniform depth of cut over the surface or bars of different shaped crosssection, such as round, square, hexagonal, etc., cross-section.

Other objects will be apparent as the invention is more fully hereinafter disclosed.

In accordance with these objects I have devised an improved means for controlling the grinding wheel pressure in the bar grinder device of the said Platt patents, one specific embodiment oi which is illustrated in the accompanying drawings to which reference now should be made.

In the drawings:

Fig. l is a front elevational View of the im.- proved bar grinder device of the present invention;

Fig. 2 is a side view of the same taken along plane 2-2 of Fig. 1;

Fig. 3 is a diagrammatic view showing the electro-mechanical control means of the present invention;

Fig. 4 is a view taken along the plane 4-4 of Fig. 1; and

Fig. 5 is a view taken along plane 5-5 of Fig. 4.

The improved bar grinder device of the present invention, as illustrated in the drawings, is one that has been designed particularly for the grinding of bars of square cross-section and consists essentially of a grinding wheel W; means sustaining the wheel to be rotatable about a horizontal axis at a substantially constant rate of speed and to be movable up and down out of and into bar grinding position; means AA to feed a bar endwise with axial rotation at a substantially constant rate of feed and rotation to the wheel W at the grinding position with the bar axis normal to the side of the wheel and with the bar at a horizontal level bringing the wheel in contact with the upper surface of the bar; means for applying a determined pressure on the wheel; and means for automatically varying the said wheel pressure as the contour of the bar surface varies during rotation to thereby maintain a uniform depth of out over the surface of the bar.

In this combination, the means A-A for axially feeding the bar with axial rotation horizontally through the grinding position is substantially the same as that disclosed in said prior Platt patents and, per se, forms no part of the present invention except as one of the means elements thereof.

The means of the present invention for sustaining the grinding wheel W for rotation and for vertical up and down movement out of and into bar grinding position consists essentially of a pivoted lever having a long arm L and a short arm L and pivotally supported at its pivot point by support S with the wheel W sustained between parallel spaced arms in bearing members for independent rotation on the short arm L of the lever in a unit assembly including pulley E and counterweight F with the weight of said wheel assembly counterbalanced on the long arm L of the lever by counterbalancing weight C, substantially as shown in the drawings. In this arrangement the wheel W is driven by motor M mounted independently on spring platform P through belt drive connection D, substantially as shown.

The means for moving the counterbalanced wheel W downwardly and upwardly into and out of bar grinding position consists of a pair of double-action pneumatic rams I and 2 mounted under the long arm L of the lever and operatively connected to the lever arm to actuate the long arm up and down with the up and down strokes of the pistions pp' of the rams l and 2, the distance of arm movement in either direction being limited by the correlated length of stroke of the pistons p-p.

Operation of the rams I and 2 is under the control of an electro-mechanical control means designed to insure that the rams operate to move the wheel W out of grinding position when a bar B is not in grinding position, and to actuate the rams I and 2 to move the wheel W into grinding position when a bar B is located in grinding position and to actuate one of said rams I and 2 as the bar B rotates to add or subtract its ram pressure from that of the other ram as the sides and corners of the square cross-sectioned bar are presented to the grinding wheel thereby to maintain a substantially uniform depth of cut over the bar surface.

Referring now to Fig. 3, the details of the electro-mecham'cal control means of the present invention may be noted. As indicated in this figure, the rams I and 2 are operated by air under pressure from supply pipe III, the particular pressure in each ram being regulated by reduction valves VI and V2, respectively. Operation of the rams I and 2 in either direction is obtained by solenoid-actuated valves V3 and V4, respectively, the valves passing the air in one position of movement through conduits I I and I2 into rams I and 2 for the upstroke and passing the air in the other position of movement through conduits I3 and I4 into rams I and 2 for the downstroke of the pistons pp.

The operation of solenoids SI, S2, S3 and S4 to shift the valves V3 and V4 into the two positions of movement is under the control of the electromechanical control means shown associated with the solenoids. In this control means, as hereinabove indicated, the objective in View is to obtain positive operation of the valves V3 and V4 to the position imparting a downstroke to the pistons pp of the rams I and 2 with resultant movement of the wheel W out of grinding position when a bar B is not in grinding position; positive operation of the valves V3 .and V4 to the position imparting an upstroke to the pistons p-p of the rams I and 2 when a bar B is located by the means A-A in bar grinding position thereby moving the wheel W into grinding position; and

to provide means whereby one of said rams I and v2 is actuated such as to add the ram pressure to the pressure of the other ram or to subtract the ram pressure therefrom as the sides and corners of the bar B, respectively, are presented to the wheel W i or grinding during bar rotation.

This result is obtained by means of

levers

20 and 2|, one of each side of the wheel W and by rotating cam 3I disposed in front of means A. The levers 20 and 2I held normally in a horizontal position by springs 5fi50', respectively, actuate when in depressed position the

switches

22 and 23. Rotating cam 3| when rotated by the engagement of bar B therewith actuates two-way switch 24. The depressing of

levers

20 and 2| and the rotation of rotating cam 3I by bar B controls the energization of solenoids SI, S2, S3 and S4 and the actuation of rams I and 2 by said solenoids to produce the desired operational result.

As indicated in Fig. 3, the electric current for energizing solenoids SI to S4, inclusive, drawn from supply lines w-b. One line (b) is connected to one side of each of the solenoids SI to S4, inclusive, through line hi, to one side of the coil 4I actuating the movable contacts of a relay switch 40 with one normally closed contact and three normally open contacts; by line he to one side of the coil 42 actuating the movable contacts of a relay switch 43 with two normally closed contacts and two normally open contacts by line In; and to one side of the coil 44 actuating the movable contacts of a. relay switch 45 with one normally closed contact and one normally open contact by lines he and 124. Line a is connected directly to one side of the four contacts of relay switch 40 .and to one side of the two normally closed

contacts

43a and 43b, and to one side of one of the normally open contacts, 430, of relay switch 43.

The solid line position of all switches, except switch 24, indicates their position when a bar B is not in grinding position. In the electric circuit, as shown in Fig. 3, solenoid S3 is energized on one side through line b, and on the other side through lines a3, a2 and a1, and normally closed relay switch contact 40a; solenoid S4 is energized on one side through line b1 and on the other side through line (2.19, normally closed relay switch contact 4522, lines a4, a2 and c1 and normally closed relay switch contact 46a; solenoid SI is deenergized since the circuit from line a. through lines are and am is broken at normally open relay switch contact 43d and the circuit from line a through lines 1116 and an is broken at normally open relay switch contact 450.; and solenoid S2 is deenergized since the circuit from line a through line 0.18 is broken at switch 24 or if switch 24 is closed (in dotted line position) across lines am and (117 (which will depend upon the position of the raised areas 3Ia. of cam 3|) the circuit from line a. through lines an; and (7.17 is broken at normally open relay switch contact 45a. With solenoids S3 and S4 energized and solenoids SI and S2 deenergized the positions of valves V3 and V4 will be such as to supply air pressure through conduits I3 and I4 moving the pistons in rams I and 2 and the long arm L of the counterbalanced lever downward with the resultant upward movement of the grinding wheel W out of grinding position.

As bar B engages lever 20 depressing same to close switch 22, relay coil M is energized by completion of the circuit back to line a through lines one, switch 22, lines as and an and through normally closed rela switch contact 43b and to line b through line 132. When relay coil 4| is energized the contact positions of relay switch 40 assume the dotted line positions of one open contact (40a) and three closed contacts (40b, 40c and 40d). Solenoid S3 is still energized through line 221 to line b and lines as, a2 and an and relay contact 43a. to line a; solenoid SI is still deenergized as none of the conditions stated above has been altered; and solenoid S2 is still deenergized as none of the conditions stated above has been altered.

As bar B engages lever 2| (bar B continuing to engage lever 20) depressing same to close switch 23, relay coil 42 is energized by completion of the circuit to line a through line 0.20 switch 23, line a1 and relay contact 402) (now in dotted-closed position) and to line b through line be. When relay coil 42 is energized the contact positions of relay switch 43 assume the dotted line positions of two opencontacts (43a and 43b) and two closed positions (430 and 43d).

Relay coil 44 is now energized by completion of the circuit to line a through line (115, relay contact 43d (now in dotted-closed position) line an and relay contact 40d (now in dotted-closed position) and to line b through lines b4 and be. When relay coil 44 is energized the contact positions of relay switch 45 assume the dotted line positions of one closed contact (45a) and one open contact (45b).

Solenoid S3 is now deenergized since the circuits lines as, a2 and or, lines as, a2 and 0.12 and lines as and 114 all lead to open relay contacts preventing a feed to the S3 coil from line a.

Solenoid Si is now energized by completion of the circuit to line b through line 121 and to line a through lines (116 and 15, relay contact 43d (now in dotted-closed position), lineaia and relay contact 40b. (now in dotted-closed position).

Assuming that switch 24 is in the dotted line position, solenoid S4 is deenergized since the circuit line am, as and as lead to open switch 24 and the circuit lines (1.19 and as lead to open relay contact 451 (now in dotted-open position) and there is therefore no feed to solenoid S4 from line a.

Assuming that switch 24 is in the dotted line position, solenoid S2 is energized by completion of the circuit to line b through line b1 and to line a. through line am, switch 24, line 0.17, relay contact 45a (now in dotted-closed position), lines am and dis, relay contact 43d (now in dottedclosed position) line an and relay contact 40d (now in dotted-closed position).

Under these conditions, of solenoids S3 and S4 being deenergized and solenoids S! and S2 being energized, the positions of valves V3 and V4 will be such as to supply air pressure through conduits H and I2 moving the pistons in rams I and 2 and the long arm L of the counterbalanced lever upward with the resultant downward movement of the grinding wheel W until the grinding wheel W engages the bar B.

As the bar B engages the rotatable cam 3| to rotate the same, which engagement occurs shortly after the closing of switch 23, the rotation of the cam 3| periodically shifts the twoway switch 24 from solid line to dotted line positions, as the high and low areas of the cam pass the switch, thereby energizing alternately solenoids S2 and S4 to move the valve V4 into positions passing air into ram 2 in opposite directions. The sum of the pressures exerted by the rams I and 2 on wheel W represents the maximum grinding pressure. The diiference between the ram pressures represents the minimum pressure. The high areas 3|a of the cam 3| are arranged with respect to switch 24 such that this minimum pressure is exerted when the corners of the rotating bar B are presented to the wheel for grinding. By an appropriate shaping of the cam areas 3|a the depth of cut at the bar corners may be closely controlled with any given grinding wheel pressure.

It is believed apparent that as the rear end of the bar B clears lever 20 permitting switch 22 to open, the current in line a1 is broken by the return of the contact 4|] to first position thereby deenergizing coil 42 and permitting contact 43 i to return to first position.

The return of contacts 40 and 43 to first position deenergizes solenoids SI and S2 and reenergizes solenoids S3 and S4 causing valves V3 and V4 to shift back to first position passing the air into rams and 2 in the direction moving the lever arm L downwardly with resultant raising of the wheel W out of grinding position. The return of contact 43 also operates to open line aw thereby deenergizing coil 44 and permitting contact 45 to return to first position, thereby deenergizing contact 24.

Referring now to Figs. 4 and 5, the details of rotating cam 3| may be noted. The spring fingers 3|] are mounted in diametrically opposite position upon the face of the cam 3| which is mounted for free rotative movement upon the tubular end of the means A within which the end of the bar B enters for engagement by the means A to continue bar feed as the rear end .6 of the bar B leaves the means A. The switch 24 is mounted in a determined position relative to the cam 3| to be actuated thereby upon cam rotation. The particular position of this switch 24 relative to the cam 3| may be widely varied without departure from the invention.

The improved bar grinding apparatus herein described and illustrated as a specific embodiment of the present invention may be widely modified without essential departure from the invention as one skilled in the art will perceive. It is believed apparent that where the bar B is provided with more than four (4) sides the number of spring fingers 3B and the number of raised areas 3|a, on the cam 3| must be correspondingly increased to effectively coordinate the operation of the switch 24 in the manner hereinabove described.

To adapt the bar grinding apparatus to use with substantially round bars, switch 24 may be electrically disconnected as the grinding pressure on round bars should remain constant.

The particular size of rams and 2 may be widely modified without essential departure from the invention as may also the relative sizes of said rams, the piston stroke and relative air pressures employed in the rams, all in accordance with engineering design or requirements. In the specific embodiment shown the two rams are of approximately the same diameter with the stroke of ram 2 greater than that of ram I such that with the two rams located in parallel alignment under the long arm L, substantially as indicated, the two rams cooperate smoothly in the movement of the lever up and down to locate the wheel W in and out of bar grinding position and to hold same under a determined maximum pressure in said bar grinding position.

Solenoid actuated valves V3 and V4 are old, per se, and many different types and kinds of such valves are available for the purposes of the present invention. In the drawings (Fig. 3) I have indicated the valves schematically for purposes of illustration and not by way of limitation,

. for one skilled in the art to readily comprehend the function of the valves in the combination of the present invention.

The particular grinding pressure to be employed on wheel W varies widely with the metallic composition of the bar, the grinding wheel composition, the rate of revolution of wheel and bar, and the rate of axial movement of the bar through the grinding position, as one skilled in the art of machine design will readily recog nize.

The apparatus of the specific embodiment has been designed for general use in the surface grinding of hot rolled bars of nickel-chromium alloys of the 80/20 type (approximately 80% Ni and 20% Or) at a size approximating 4 inches square. With this type of bar at a forward rate of feed of about 80 feet per hour and a bar rotating rate of 31 revolutions per minute, the grinding pressure varies directly with the kind and type of grinding wheel W employed. With grinding wheels of standard composition a grinding pressure of about 30 to pounds per square inch has been found eifective as maximum and minimum pressures to produce consistently good re-- sults on bars of this metallic composition having this approximate size.

As the rate of bar feed andbar rotation by the means AA' may be varied widely, the selection of the proper grinding pressure on any given bar under any given set of grinding conditions may be approximated relatively closely and adjusted to the optimum for best results.

Having hereinabove described the present invention generically and specifically and given one specific embodiment of the same, it is believed apparent that the invention may be widely modifled without essential departure therefrom and all such modifications and departures from the invention are contemplated as may fall within the scope of the following claims:

What I claim is:

1. A bar grinder device comprising in combination, a grinding wheel, mean sustaining the wheel to be independently rotatable about a horizontal axis and to be movable up and down out of and-into a grinding position, means for feeding a bar endwise with axial rotation to the wheel at the bar grinding position at a horizontal level bringing the wheel into pressure contact with the upper surface of the axially moving and rotating bar, a pneumatic ram means for moving the wheel into and out of bar grinding position and means automatically varying the ram means pressure with variation in the contour of the rotating bar to thereby maintain a substantially uniform depth of grinding cut over the surface of the bar.

2. A bar grinder device comprising in combination, a pivoted lever having a short arm and a long arm, a vertical support sustaining the lever at its pivot point, a grinding wheel and means mounting the wheel on the short arm of the lever for independent rotation about a horizontal axis, a counterbalancing Weight on the long arm of the lever, a drive motor and means sustaining the motor independently the lever in a position to drive the wheel, means for feeding a bar endwise to the wheel at a horizontal level below the horizontal level of the said lever, said means including means to simultaneously rotate the bar-about its axis, and pneumatic means for moving the long arm of the lever up and down to move the wheel into and out of grinding engagement with the upper surface of the axially moving and rotating bar, said means includin means to apply a determined pneumatic pressure onto the lever and means automatically varying the pneumatic pressure with variation in bar contour thereby to maintain a substantially uniform depth of grinding cut over the surface of the bar.

3. A bar grinder device comprising in combination, a pivoted lever having a long arm and a short arm, a vertical support sustaining the lever at its pivot point, a grinding Wheel and means securing the wheel for independent rotation on the short arm of the lever, a counterbalancing weight on the long arm of the lever, a drive motor and means connecting the motor to the wheel for wheel rotation, a pneumatic ram means operatively connected to the long arm of the lever to move the lever arm up and down a determined distance movin the wheel into and out of bar grinding position, means for feeding a bar endwise with axial rotation through the bar grinding position at a horizontal level locating the grinding wheel on the upper rotating surface of the bar, and means to vary the pneumatic pressure of the said ram means automatically with variation in bar contour thereby to maintain a substantially uniform depth of grinding cut over the surface of the bar.

The combination of claim 3, wherein said pneumatic means comprises a pair of double acting pneumatic rams operatively connected in parallel to the said long arm of the lever and wherein said means to vary the pressure of said ram means automatically consists of a pair of solenoid actuated two-way valves, one for each ram, means connecting the rams to a source of air through said valves to pass a determined pressure of air into the rams in each direction, and an electro-mechanical control means including the solenoid actuatin elements of said valves for energizing the said solenoids to move the valves to the position passing air into the rams in the direction raising the wheel out of the grinding position when a bar is not located in grinding position, to energize the solenoids oppositely when a bar is located in grinding position, and to energize one of said rams separately as the bar rotates while in grinding position to add its pressure to or to subtract its pressure from the pressure of the other ram as the sides and corners of the rotating bar are presented to the wheel for grinding.

5.'The combination of claim 4, said electromechanical control means consistin of a depressible lever arm on on side of the wheel in a position to be depressed by a bar as it approaches the grinding position, a second depressible lever arm on the opposite side of the wheel in a position to be depressed by a bar as it leaves the grinding position, a rotatable cam means disposed in a position adjacent to the second lever to be engaged by and rotated by the bar as it leaves the second lever, an electrical circuit including the solenoid actuating means of said valves and switches actuated by said levers and cam directing the electric current energizing said solenoid actuating means to the solenoids actuating the said valves to pass air to both rains in the direction raising the wheel out of grinding position when the first lever is not depressed, to energize the same oppositely when both levers are depressed and to energize one of said solenoid actuating means only when the said cam is being rotated, the said cam having a cam surface corresponding to the contour of said bar and the said switch means actuated by the high and low areas on the cam directing the energizing current to the solenoid actuating means of the said valve of the said one ram to actuate the same forward and reverse to add or to subtract its pressure to or from the pressure of the other ram in conformity with the high and low cam areas.

6. An electro-mechanical control means for a bar grinder device having a horizontally sustained pivoted lever with a grinding wheel mounted for independent rotation on one end and a counterbalancing weight on the other end, a pair of double actin pneumatic rams operatively connected to the said other end of the lever to raise and lower said end a determined distance moving the wheel into and out of a bar grinding position and means for feeding a bar endwise with axial rotation past the Wheel in bar grinding position at a horizontal level permitting the wheel to make grinding contact with the upper surface of the moving and rotating bar, said control means comprising a pivoted lever on one side of the wheel in a position to be pivoted as a bar approaches the wheel, an electric switch means disposed in a position to be actuated by the pivoted lever, a second pivoted lever on the opposite side of the wheel in a position to be pivoted as a bar leaves the grinding wheel, an electric switch means disposed in a position to be actuated by the pivoted lever, a rotatable cam having an exterior contour conforming to the contour of said bar, said cam being disposed adjacent the second 9 lever in a position to be engaged and rotated by the rotating bar as it leaves the second lever, a switch means operatively connected to the cam to be operated in one of two positions corresponding to the high and low spots on the cam surface upon cam rotation, a two-way valve for each said ram, a solenoid actuating means for operating each of the valves in each direction and an electric circuit including the said solenoids and the said switches to direct the energizing current to the said solenoids in the direction moving the wheel out of grinding position when neither lever is depressed, into bar grinding position when both levers are depressed, and to actuate one ram to add its pressure to the first ram when the low spots of the cam corresponding to the sides of the bar actuate the cam switch in one position and to subtract its pressure from that of the first ram when the high spots corresponding to the corners of the bar actuate the cam switch.

STANLEY RUSSELL ELLISON.

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

UNITED STATES PATENTS Number Name Date 2,088,737 Forbes Aug. 3, 1937 2,347,503 Platt Apr. 25, 1944 2,505,223 Whitcomb Apr. 25, 1950