US1333445A - Automatic grinder-stone dresser - Google Patents

Description

F. E. RILEY.

AUTOMATIC GRINDER STONEJDRESSER.

APPLICATION FILED JULY 25,1919.

Patented Mar. 9, 1920.

3 SHEETS-SHEET I- I .2 an

III/VENTOR ATTORNEYS I I I WITNESSES F. E. RILEY.

AUTOMATIC GRINDER STONE DRESSER.

APPUCATlON FILED JULY 25.1919. 1,333,445. Patented Mar. 9, 1920.

3 $HEETS-SHEET 2- WITNESSES g INVENTOR W ATTORNEYS F. E. RILEY.

AUTOMATIC GRINDER STONE DRESSER.

I APPLiCAT DN FILED JULY 25| I919. 1,333,445. Patented Mar. 9, 1920.

3 $HEETS-SHEET'3.

JEWLZZ WITNESSES 4 TTORNEYS FRED E. RILEY, OF LIVERMORE FALLS, MAINE.

AUTOMATIC GRINDER-STONE DRESSER.

Specification of Letters Patent.

Patented. Mar. 9, 1920.

. Application filed July 25, 1919. Serial No. 313,284.

To all whom it may concern.-

Be it known that I, FRED E. RILEY, a citizen of the United States, and a resident of Livermore Falls, in the county of Androscoggin and State of Maine, have invented a new and Improved Automatic Grinder- Stone Dresser, of which the following is a full, clear, and exact description.

This invention relates to a number of important specific improvements over the subject matter of Letters Patent of the United States No. 1,268,624, issued to me on the 4th day of June, 1918.

Among the objects of the invention is to so improve the construction as to make it more practical and reliable in use and accurate in operation.

More specifically stated among the objects of the present improvement is to provide a main carriage having inlet and eX- haust ports for the power fluid formed directly therein.

Another object of the invention is to provide improved specially constructed valves and operating means therefor of an automatic nature whereby the continual to and fro reciprocation of the main carriage and a similar forward and rearward movement of the cross feed motor may be acand the main carriage through which I am able to secure any desired extent of reciprocation of the cross feed motor with a rela tively slight reciprocation of the valve shifting member actuated by or from said cross feed motor.

With the foregoing and other objects in view the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in Which- Figure 1 is a plan view, the bur being indicated at the moment it is about to begin its cutting operation, the bur moving toward the right in such operation as depicted in the present illustration.

Fig. 2 is a vertical longitudinal section on the line 2-2 of Fig. 1.

eating the lever bar in retracted position;

and

Fig. 9 is a fragmentary side elevation indicating the manner of securing the hand wheel sleeve to the shifting block stand as will be seen from the line 99 on Fig. 1.

While this specification is intended to be complete as'to the novel details of construction distinguishing it from the subject matter of the earlier patent, no attempt will be made herein to elaborate on the general objects or purpose of this type of machine since such features were fully set forth previously.

10 indicates a main stationary base having at one end a girth 11 to which, is fixed a stationary piston rod 12 hearing at its oppositeend' a piston 13. The cylinder 14 is reciprocated over the piston toward the right by power fluid admitted between the piston and the end cap 15, and toward the left by power fluid admitted subsequently between the piston and the end 16 of the cylinder. The upper portion of the carriage to which the cylinder is connected may be termed a cover at 17 and this as indicated in Fig. 7 is provided with longitudinal inlet and waste ports 18 and 19 respectively from each of which leads a branch port 18' or 19' to and from the valve mechanism of the cross feed motor. The ports 18 and 19 communicate with a valve chamber 20 suitably bored out and fitted with a liner 21 consisting of a short vertical cylinder within which v the cross feed motor, being controlled by- .other.

is journaled a valve 22 controlling the power fluid for the main carriage. Said liner is bored radially with a plurality of holes opposite each of the inlet and waste ports, the capacity of each group of ports formed through the liner opposite each main port being equal to at least that of the main port.

Among the objects of the cylindrical liner are: First, the provision of a structure adapting the use of a high quality of metal at moderate cost which will resist corrosion and afford the best operating conditions; secondly, the relief from obligation of the builder of the machine to accurately turn the chamber in which the liner is fitted, and thirdly the formation of the small holes provides for the use of a softer quality of packing 23 which will glide freely over the holes than could be used in this type of valve if a large hole were formed in direct communication with the valve.

lVith the valve adjusted as shown in Fig. 7 pressure fluid admitted through the port 18 and by-pass 24: through the valve' will pass thence through a longitudinal port 25 to the space between the piston and the cap 15 for the purpose of driving the carriage toward the right as viewed in Figs. 2 and 7. At the same time the same pressure fluid will pass through the auxiliary port 18 to the valve 26, (see Figs. 3 and It will thus be seen that the power fluid from the same source is applicable directly to each of the valves 22 and 26, but said valves may be actuated independently of each lVhen the power fluid is admitted through the valve as shown in Fig. 7 from the inlet 18 the waste from the left side of the piston 18 will pass out through the port 27. passageway 28 in the valve, and thence. out through the waste port 19.

The character of the valve 26 in most respects is similar to that of the valve 22 especially with respect to the liner 29 in which the valve is fitted for oscillation. The valve as shown in Fig. 5 is set to release the bur 30 for withdrawal fromthe stone 31. Consequently at this time the passage of the power fluid from the port 18 will be through the by-pass 32 through the valve, and thence through the port 33 to the rear of the piston 34 mounted in the cross feed motor cylinder 35. During this release of the bur the waste water from the front side or left of the piston as shown in Fig. 3 will be discharged through the port 36 and by-pass 37 through the valve to the waste port 19.

Referring now more particularly to the valve construct-ion fixed to the upper end of the valve spindle is a pinion 38 with which mesh the teeth of an internal rack 39 carried by a plate -10 journaled for oscillation around a stud 11 fixed to a plate 42 and carried by the upper surface of the carriage and through which the valve stem is journaled. The rack 39 is concentric with the stud 41 and is adapted to oscillate through a small angle and limited by lugs l3 adapted to strike in alternation against a fixed stop 44. A slight angular rotation of the plate around its pivot acting upon the small pinion 38 will be sufiicient togive the valve a quarter rotation for the purpose of reversing the direction of movement of the carriage first to make the cutting strokeand then make the return idle stroke of the cutting bur. The upper portion of the plate 40 consists of a barrel 45 having a horizontal bore in which is slidably fitted a plunger 46 having on its inner end a head 47 and on its outer end a handle 18. The intermediate portion of the plunger is provided with a radial pin '49 operating normally in an are shaped slot 50 adjacent to one end of the barrel. Said slot terminates in a horizontal slot 50' leading out from the outer end of the barrel or a collar 51 constituting the end of the barrel so as to bring the plunger into the position shown in Fig.

8 with the pin 49 on the outside of the barrel. At this time the head 47 is housed within a pocket 52 at the inner end of the barrel and in idle position, at which time the operator w1ll manipulate-the handle 48 for rotation of the valve independent of any automatic mechanism associated therewith for normal operation. The pin 49, however, when in the are shaped slot 50 will hold the plunger extended as in Fig. 1 for automatic actuation.

The means for controlling the position and action of the bur 30 toward and from the stone 31 includes the cross feed motor. the piston and valve. all of which havealready been referred to. Said motor includes a slide 53.n1ovable'in guideways 5-1 transverse to the direction of movement of the main carriage 17. The bur is journaled in a fork having a shank 55 clamped adjustably in the slide. 56 constitutes an upstanding yoke at the front end of the slide in which the upper end of the piston rod 57 is fixed rigidly. Consequently when the piston 34 is forced forward or toward the stone the slide and parts carried thereby will be correspondinglyactuated.

Oneof the most important features of novelty distinguishing this invention from the previous one lies in the means for actuating the valve 22 through the plunger 46 as the result of the forward and rearward reciprocation, of the motor slide 53. the valve being actuated through its full stroke of 90 degrees at the end of each re ciprocation of the slide and irrespective of the length of the stroke of the slide, at the same time the member actuated by the slide for oscillating the valve mechanism operates only a short distance. This mechanism comprises a box 58 slidable in dovetailed guideways 59 (see Fig. 2) between the slide 53 and the main valve and parallel to the slide, one side of the box being open at 60 and into which the end of the yoke 56 projects. (See Fig. 6). This projecting end of the yoke is provided with a. threaded hole 61 through which the threaded portion of a feed screw 62 extends. The feed screw has at one end a head 63 which is adapted to impinge against the adjacent end of the box 58 when the slide 53 is making its forward stroke toward the stone whereby the box will be carried in the same direction for turning. the main valve -2'2- in a clockwise direction or to the position of Figs. 1 and 6. 64 indicates an extension of the box in which is journaled a sleeve 65 to which the hand wheel 66 is connected for rotation of the sleeve, the interior ofwhich is polygonal for cooperation with a similarly formed shank portion 67 of the screw. (See Fig. 9). The sleeve 65 is held from endwise movement with respect to the extension 64 by means of a clip 68 embracing a collar 69 formed on the sleeve. (See Fig. 9). Except for the slight reciprocation of the feed box 58 which in practice approximates about three quarters of an inch, there is no reciprocation of the handle and hence it is very easy for the operator to have complete control of the adjustment of the screw at all times and with perfect safety. The reciprocation of the feed box toward the stone is positively limited by means of a screw 70 locked in a lug 71 integral with the feed box, or its extension 64:, said screw being adapted to impinge directly against the main carriage. This stop mechanism acts in conjunction with the stops 43 and 44. The motor piston 34. under the force of the motive fluid carries the slide 53 and the bur toward the stone and the variation or adj ustment of the length of such stroke or movement of the slide and bur is determined delicately by the rotation of the screw 62 in the yoke 56 whereby the space between the head 63 and the adjacent end of the box 58 I is varied. More definitely at the end of each stroke of the bur across the stone the operator will give the hand wheel av sliding turn so as to withdraw the head 63 slightly from the end of the box, or with a left turn as shown in Fig. 6. Consequently on the next forward stroke of the bur toward the stone the slide will move a little farther before the screw will act to shift the box and cause the reversal of direction of the main motor. When the cross feed motor is given its upward stroke thelyoke 56 as it nears the end of its stroke will strike against the opposite end of the box and so cause the main valve to be reversed again. The connection between the plunger head *7 and the box depends upon a. clip 72 adjustably fixed upon the upper surface of the box as shown in Fig. 1. and which has fairly close contact with said head when the head is in operating position or extended around the pocket 52.

The stem of the valve 26 is fixed to a pinion 73 meshing with an internal rack 7% carried b a plate 75 and pivoted on a stud 76. ee Fig. 3). These parts are similar in construction and action to the corresponding parts of the main valve already described. A hand controlled plunger 77 has at one end a head 78 and at the other end a handle 7 9, the control and manipulation of this plunger being similar to that of the plunger 46. The head 78 in normal automatic operation is adapted to impinge against a stop device 79 at either end of the base 10 just as the main carriage is approaching the limit of such stroke and by actuating said head relatively to cause a slight rotation of the plate 75 the valve 26 will be turned through 90 degrees to cause the reversal of the piston 34. As in the previous patentwhen the main carriage reaches the end of one reciprocation the cross feed motor will carry the bur into engagement with the stone and by the time the bur reaches the stone the valve will have been shifted to cause the motive fluid to actuate the main carriage parallel to the stone, the rotation of which stone will cause the rotation'of the bur and the dressing of the surface of the stone. VV-hen the cutting stroke of the bur across the face of'the stone is completed the stop 79 at the point to be struck by the head 78 of the cross motor valve structure causes the shifting again of the valve 26 to cause the power fluid to withdraw the bur from the face of the stone as shown in dotted lines in Fig. 1. During this movement of the cross feed motor the main carriage will have continued in its same direction until limited by the striking of the hub 16 of the cylinder end 16- against. the piston 13. Immediately thereafter, however, the outward movement of the cross feed motor and bur from the stone will effect the reversal of the main carriage valve to .the position shown in dotted lines in Fig. 1 so that the motive fluid will return the carriage and bur idly toward the left. The plunger head 78 at this time will be in its forward position and when it strikes the lug 79 atthe opposite end will cause the reversal of the valve '26 and the forward movement of the slide and bur into cutting position again. The movement of the carriage toward the position in full lines in Fig. l is positively limited by contact of the adjustable screw 80 impinging against the outer end of the piston rod 12 or piston fixed-thereto. (See Fig. 2)

The base 10 upon which are fitted and supported all of the mechanism above described is adapted to be adjusted around the axis of the piston rod 12 as shown in Fig. 3 by virtue of bolt and slot connections 81 with the main support and thereby the angle of incidence between the bur, fork and the stone may be varied, an item of importance in many instances.

In the practice of this invention it frequently happens that the shim, chip or the like of wood or other material will be caught between the bur and the stone when power is applied to the bur tending to hold it against the stone. This circumstance is apt to prove disastrous unless the pressure fluid can be relieved promptly as by means of a safety'valve 82 of any suitable nature shown herein as applied to the outer end 83 of the cylinder 35. This valve per 86 may be of any suitable construction, but is adjusted to act at a sufiiciently higher pressure than the normal pressure of the fluid so as not to interfere with the normal operation of the machine. In this connection it is to be observed that for the best operation of the bur the power fluid acting to hold it in contact with the stone should be substantially constant in force. In order, therefore, to maintain this force constant or at a maximum I provide some suitably arranged check valve 8% between the inlet port 18' and the valve 26. This valve Si is acted upon by a spring 85 tending to close the valve in a reverse direction to the direction of the power fluid. Under normal conditions the power fluid is maintained at a substantially uniform pressure throughout both motors, the valve 84 being held open against the force of the spring 85. If, however, the cutting operation is in progress and with full pressure in the cross feed motor cylinder and the pressure at the source of the motive fluid shall drop without the valve 84 the pressure in the bur actuating motor would likewise drop and cause an uneven action of the bur on the stone, but with the valve as shown the instant pressure back of the cross feed motor drops the valve 8-;t immediately closes and thereby the full pressure is sustained in the cylinder 35. This machine is adapted for either right or left cuts with corresponding readjustment of the controlling devices. Consequently the casing of the valve 26 is provided with a plug 86 adapting the rotation of the check valve to the other side.

I claim:

1. In a machine of the class set forth, the combination of a machine, a fluid pressure motor to reciprocate the carriage, a cutting tool, a cross feed motor including a slide to carry the tool in directions transverse to the movement of the carriage, independent valve means for said motors, and means to convey power fluid toward and from both valve means through the body of said main carriage. I

2. In a machine of the class set forth, the combination of a tool, fluid pressure means to actuate the tool in one direction, a main support for the tool and its actuating means, a fluid pressure motor to actuate said main support in a different direction from that of the tool, a source of pressure fluid common to both motors whereby both motors may be actuated at the same time, and automatic means to maintain a substantially uniform pressure in one of the motors if the pressure acting on the other motor should drop.

3. In a machine of the character set forth, the combination of a cutting tool, a reciprocating fluid motor to actuate the tool in certain directions, a main carriage supporting the tool and its motor, a second motor toactuate the carriage in different directions from the direction of movement of the tool, a source of power fluid leading through the main carriage to both motors, and automatic means serving to maintain a substantially uniform pressure in the tool motor even though the pressure through the main carriage motor may fluctuate.

4. In a grinder stone dresser, the combination with a cutting tool, automatic means to actuate the tool toward and from the face of the stone, other means to carry the tool in directions at right angles to the aforesaid movement, and movable valve means to control the action of the last mentioned means, of means operated from the first mentioned tool moving means to shift the valve means and including a box movable parallel to the movement of the tool but to a less distance, and a member carried by the box having constant engagement with a member proj ectin from the valve.

5. n a machine of the class set forth, the combination of a carriage, a motor to reciprocate the carriage, a cross feed motor supported upon the carriage, a tool slide reciprocated by the latter motor at right angles to the direction of movement of the carriage, a box mounted for reciprocations parallel to the slide but to a less distance, a valve to control the first mentioned motor, said valve including a plunger, means to. cause the movement of the box from the slide as the slide reaches the end of its reciprocation, and a plunger having a projecting end and a member serving .to make constant connection between said plunger end and the box.

6. In valve actuating means for grinder stone dressers, the combination with a rotary valve, a plate pivoted on an axis parallel to the axis of the valve, said plate having an internal gear rack, a pinion fixed to the valve stem and meshing with said rack, and

a member carried by the plate transverse to its pivot and having a short arm projecting beyond the pivot from the rack, of a slidable plate, and a member fitted in said barrel bore with one end projecting beyond the axis of the plate remote from the valve connections, of, a sliding member and a clip carried by said sliding member having close engagement with the projecting end of the iember carried by the barrel whereby a short movement of the sliding member will cause a considerable movement relatively of the valve.

8. In a valve actuating means for grinder stone dressers, the combination with an oscillating valve plunger, of a box, means to" support the box for reciprocations transverse to the axis of the valve, permanent operative connections between the box and said plunger, a power operated device movable parallel to the box, lost motion connections between the power device and the box providing for greater movement of the power member than for the box, and means to cause the limit of extent of movement'of the box.

9. In a grinder stone dresser, the combination of a tool carrier comprising a slide, means to operate the slide, a slidable box parallel to the slide, said box having an open side and the slide having a'projection extending into said open side of the box, a,

feed screw threaded in said projection and adapted to impinge against a portion of the box as the slide approaches the end of its reciprocation, a power controlling valve, and connections between the box and the valve to cause the quick movement of the valve as a result of a short stroke of the box, substantially as set forth.

.10. In controlling means for a grinder stone dresser, the combination of a tool carrier including a slide movable toward and from the stone, a box arranged to reciprocate parallel to the slide but to a shorter distance, said box having an opening atone side of the slide having a projection extending through the opening into the box, an adjustable feed screw threaded in said extension and adapted when the slide approaches the end of one reciprocation to strike against a portion of the box to move the box, a slide extension being adapted to strike against a portion of the box when the slide approaches the end of another reciprocation, a power controlling valve, and connections between the box and the valve serving to cause a relatively large movement of the valve from a small movement of the box in either direction;

11. A valve mechanism for grinder stone dressers, the combination with a valve, a plateeadjacent to the valve, said valve and plate being mounted for relatively great reciprocation in a direction at an angle to the direction of movement of the plate, said plunger having means for hand manipulation thereof independent of the automatic means.

FRED E. RILEY.

and small movements respectively, the

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