US2503760A - Automatic feeding device - Google Patents

Description

Aprxl 11, 1950 c. J. MURRAY ETAL AUTOMATIC FEEDING DEVICE 5 Sheets-Sheet 1 Filed Jan. 14, 1947 INVENTORS.

CARL J. MURRAY. WALLACE K.

ATTO R N EYS.

April 1950 c. J. MURRAY ETAL 2,503,760

AUTOMATIC FEEDING DEVICE Filed Jan. 14, 1947 5 Sheets-Sheet 2 INVENTORS CARL. J. MURRAY. WALLACE K.Lo.vvz-:.

ATTO R N EVS April 11, 1950 c. J. MURRAY EI'AL AUTOMATIC FEEDING DEVICE 5 Sheets-Sheet 4 Filed Jan. 14, 1947 Iii,

Jill

I N verb-r025. CARL. J. MURRAY. WALLACE K.Low W M l M ATTORNEYS April 11, 1950 c. J. MURRAY ETAL 2,503,760

' AUTOMATIC, FEEDING DEVICE Filed Jan. 14, 1947 5 Sheets-Sheet 4 CARL J. MURRAY. WALLACE K.Lows.

ATTORNEYS.

Ap 1950 c. J. MURRAY EI'AL 2,503,760

AUTOMATIC FEEDING DEVICE Filed Jan. 14, 1947 q 5 Sheets-Sheet 5 a I a "CARL J. Mu RRAY.

ATTORNEYS.

INVENTORS.

Patented 11, 1950 i OFFICE AUTOMATIC FEEDING DEVICE Carl J. Murray, Liverpool, and Wallace K. Lowe,

Syracuse, N.

Y., assignors to Crucible Steel Company of America, New York, N. Y., a corporation of New Jersey Application January 14, 1947, Serial No. 721,930

7 Claims. 1

.This invention relates to apparatus for consecutively' and automatically feeding objects from a group thereof into operative engagement with apparatus for acting upon said objects, and more particularly to automatic means for feeding sub- I stantially cylindrical objects successively into operative engagement with, for example, a grinding and polishing device.

In the mass production of certain types of objects which are to undergo, for example, certain repetitive fabricating operations, it is often desirable to hold a plurality of such objects within suitable retaining means such as a magazine or tray and consecutively to discharge said objects therefrom and into operative engagement with the device which is to operate thereupon. An example of this is found in the manufacture of cylindrical objects such as metal rods wherein it is desirable to grind and polish the finished product. Also, with respect to certain types of rods, it is necessary to grind same to exacting dimensions after forming by extrusion, casting, etc. In the past it has been standard practice to accumulate large quantities of such rods adjacent to polishing and/or grinding machines and to feed each rod by hand successively into the device.

This has been a serious drawback to mass production and has resulted in a bottle-neck in the manufacture of many items, which bottle-neck can be overcome only by employing large numbers of, for example, grinding or polishing machine operators.

The hand feeding of such machines is not only a drawback to production but has resulted in an appreciable increase in costs of production not only because of the labor costs involved but because of the slowness of manual operation.

According to the present invention, apparatus is provided for overcoming the above noted difficulties.

Various further and more specific features and advantages of the invention will clearly appear from the detailed descriptiongiven below taken in connection with the accompanying drawings which form a part of this specification and illustrate, by way of example, preferred arrangements of apparatus for carrying out the invention. The

invention consists of such novel combinations and features of apparatus as may be shown and described in connection with the equipment herein disclosed. In the drawings:

Figure 1 is a front elevation of one embodiment of the invention;

Fig. 2 is a fragmentary cross-sectional view with parts broken away illustrating the rod holding and moving members as shown in Fig. 1;

Fig.3 is a perspective viewwith parts broken away illustrating a tray for holding a plurality of cylindrical objects, such as rods, in a stacked relationship, and also illustrating a portion of an automatic feeder and grinder;

Fig. 4 is a sectional view of the tray shown in Fig. 3 with a portion thereof in a different operative position;

1 Fig. 5 is a fragmentary enlarged detail view of a portion of the apparatus shown in Fig. 4;

Fig. 6 is a top plan cross-sectional view with parts broken away of a master control valve employed in the present invention;

Fig. 7 is a side elevation, partly in section, of the valve shown in Fig. 6;

Fig. 8 is a cross-sectional view of a bleeder valve employed with the master control valve of Fig. 6;

Fig. 9 is a cross-sectional view of a speed control valve for governing the speed of the reciprocating feeder illustrated in Fig. 1; and

Fig. 10 is a schematic illustration of a second embodiment of the present invention.

Novel means are disclosed herein for feeding into apparatus, such as grinding and polishing devices, objects which are to be acted upon thereby. Said novel means overcomes the above mentioned diificulties of manual feeding and makes it possible for one man to supervise the rapid feeding of a plurality of machines, instead of said man being confined to a single machine which can be fed only by slow manual operations.

Referring to the drawings in further detail, the novel apparatus comprises in general a grinding and polishing device 20, a magazine 2| for holding a plurality of rods in readiness to be fed successively into the grinder, and an automatic reciprocating mechanism 22 for thrusting said rods one at a time into operative engagement with the grinder.

Grinding apparatus (20) cal object is urged against the belt for grinding purposes, and which means are adapted for urging said object axially whereby the abrasive action of the belt is applied to the entire length of the rod. Such means in the form shown are constituted by a feed roller 28 mounted for rotation upon a shaft 29. The latter shaft in turn is mounted upon a tiltable frame 88 (Fig. 1). The frame 88 may be tiltable about the axis of a shaft 8| which is perpendicular to the belt 23. The surface of roller 28 also may be abrasive.

The reason for tilting the feed roller 28 relative to th direction of motion of belt 23 is to provide a component of force which will urge a rod axially in the direction of the tilt, for example, as shown by the arrow 32 in Fig. 1. The roller 28 may be driven by any suitable means, for example, by means of the motor 28 through the intermediary of a belt 28a which actuates suitable gearing (not shown), and by a belt 88 which engages a pulley 84 upon the roller shaft 29.

Means may be provided for adjustably controlling the tilt of th roller 28 comprising a handle 35 which may be rigidly attached to said frame member 88 and positionable to a desired angle and there held by means, for example, of a suitable adjusting nut.

In normal operation, the axis of roller 28 is held parallel to the belt 28 with the surfaces thereof in spaced relation, the distance between them being a function of the diameter of the rod which is to pass therebetween. Some support must b given to the belt 23 in order to insure a positive contact of the rod, the roller 28 and said belt. Said means in the embodiment shown in Fig. 3 comprise a pair of small rollers 88 and 81 which are situated on the inner side of said belt, preferably in spaced relationship, slightly above and below the roller 28. The rollers 86 and 81 may be urged against the belt 23 by suitable resilient means (not shown) or they may be rigidly held in suitable fixed supports therefor.

Magazine (21) Novel means are provided for holding a plurality of objects such as rods 38 in a stacked relationship whereby they may move rapidly and easily into a position from which they may be fed successively to the above described grinder device. Said means comprise a tray 89 (Fig. 3) for supporting 'a relatively large number of rods. The tray may be slanted to cause the rods to roll downwardly toward one edge thereof into a discharge position. A dlscharge barrel 48 or discharge support member of novel construction is situated at the lower edge of said tray into which one rod at a time may roll and from which each rod successively may be discharged and thrust into operative engagement with the centerless grinder by means of a reciprocating push rod to appear later.

The novel tray 89, in the form shown, is constituted preferably by two parts 89a, 391) which are respectively termed a charging tray and a magazine tray. The magazine tray may be fixedly mounted in a slanted position as shown whereby rods may roll successively into said discharge barrel 48. The charging tray may be angularly shifted about hinges 4i and lowered to a horizontal position to facilitate loading same. Rods or material arranged in the charging tray may be discharged into the magazine tray until the latter is filled at which time the charging tray may be filled to act as an extension of the magazine was Means are provided for holding the charging tray 88a in alignment with the magazine portion 89b when the device is in normal operation, and, as above mentioned, for permitting angular movement of part 88a into a horizontal position when it is desired to load same. Said means constitute, for example, an angularly shiftable tray support arm 42 (Fig. 4) which is pivotally mounted as at 48. Arm 42 is in the position indicated in solid lines in Fig. 4 when the tray is in its normal operative position, but may be shifted angularly to the position indicated by broken lines in said figure when it is desired to lower the art 89a to the horizontal. When the latter occurs, said chargin tray, of course, will assume the position also indicated in broken lines.

The tray 39 preferably is constituted by a suitable sheet metal member having parallel flanges 44 and 45 along the slanted sides thereof.

There may be provided on the bottom of the tray 39 a plurality of rail members such as 48, 41 and 48, which may be situated respectively one adjacent each of the sides of the tray and one in the center thereof. Said rail members facilitate a rolling action of the rods 88 by reducing fricion.

The above mentioned discharge barrel 48 constitutes the lower margin of the tray 39 and comprises means for receiving one of said rods at a time and for holding same in a position from which it may be discharged from the tray by means of the automatic reciprocatin apparatus 22 which will be described hereinafter. Barrel 48 may be a cylindrical shaft member having a groove 48a formed therein having a cross-sectional area substantially equivalent to a quadrant of the cross-sectional area of the cylindrical shaft. This is clearly indicated in Fig. 4 wherein one of the rods 38 is resting in said groove and is thus prepared for discharge. The barrel 48 may rest, for example, in suitable supports 49 and 58, the latter being a part of and rigidly supported by the reciprocating device 22.

As shown in Fig. 2, it may be desirable for the barrel 48 to extend into said support 58 whereby a positive alignment is obtained between the barrel and the cylinder of said reciprocating device.

In addition to the side flanges 44, 45, above mentioned, which are adapted for holding the rods 38 in place by preventing them from moving axially oifof the tray, there may also be provided a pair of arms 5i and 52 which may be positioned over the respective extremities of the rods 38 and in spaced relation thereto whereby the rods are prevented from moving upwardly and thus are prevented from jumping out of the tray.

In order to permit the loading of the tray, it is, of course, desirable to adapt the portions of the arms 5! and 52 which are over the charging tray 88a for angular movement. As shown in Figs. 3 and 4, arm portions 5Ia and 52a are so adapted and respectively may pivot about 5Ib and 52b.

Arms 5m and 52a preferably are rigidly interconnected by means of a handle rod 53. As shown in Fig. 4, the handle rod 53 together with arms 5Ia, 52a may be lifted to the position indicated in broken lines to place the tray in condition for loading.

If it is desired, there may be attached to the inner extremities of arms 5m and 52a suitable lugs 5lc and 520 respectively (Figs. 3 and 4). The

function of said lugs is to block the passage of rods 88 to the slanted portion of the tray (89b) when said arms are raised to the position ins jicated in broken lines in Fig. 4. Thus, the rods the interruption of the movement of the rods "when the arms |a, 52a are in their raised position. or course, normally this occurs only when it is desired to load the tray. However, if the operator of the machine desires to stop the flow of rods from the charging tray to the discharge position, he may do so simply by shifting said arms 5| a, 52a to their raised position.

In order to adjust the clearance between the rods 38 and said arms 5| and 52 at a point adjacent the discharge end of the tray, suitable adjusting screws 53 may threadedly engage portions of said arms 5| and 52 as shown in Fig. 5 whereby said arms may be lifted or lowered in response. to rotation of said adjusting screws.

Automatic reciprocating device (22) The automatic reciprocating means above mentioned constitute in the form shown a reciprocating piston 54 (Fig. 2) which moves back and forth .within a power cylinder 55 in response to controlled fluid pressure. Said fluid may be, for example, oil but preferably constitutes air and the apparatus shown herein is designed for the control of pneumatic pressure.

The piston 54 may be provided with a suitable pusher rod 56 which is adapted for reciprocating movement within a bore 48b formed within that extremity of the barrel 48 which may be introduced into an extremity of the cylinder 55, the insertion of said support member being for the purpose of securing a fluid-tight joint therewith. The thrust rod 56 is adapted for engaging a rod 38 as shown in Fig. 2 and for thrusting same into engagement with said roller 28 and belt 23. A suitable piston or guide rod 54a is attached to the piston 54 and reciprocates therewith in a manner to be described more fully hereinafter.

The means for controlling air pressure to the cylinder 55 and thus for reciprocating the piston 54 comprises a master control valve 51 (Figs. 1. 6 and 10).

Air under pressure is directed to the master control valve through a conduit 58. Interposed in this conduit are a gate valve 58, a safety valve 68 and a pressure regulator valve 6!. Suitable manual adjusting means may be provided for these valves. A pressure gauge 62 also may be connected to the conduit 58, and it is desirable for suitable valve lubricating means as at 68, also to be connected therein. The function of the lubricator is to provide sufflcient oil to insure eflicient operation of the master control .valve '51.

piston 51a. By controlling the piston of the valve piston, it is possible to control the direction of air under pressure from the intake 58 Q to either of the conduits 68 or 18 which are connected to opposite ends of the power cylinder 55.

The valve piston 51a is reciprocable within a valve body H having therein a cylindrical gate member 12 (Figs. 6 and 7) which surrounds the central portion of the valve piston. The gate member 12 is provided on the periphery thereof with a plurality of grooves l8, l4 and I5 which are in communication with a central bore or chamber 16 which is formed axially of said gate member. Said grooves may be in communication with the bore 16 by means of, for example, perforations 13a, 14a and 15a.

As will be seen from Fig. 7, the groove 14 is in communication with the intake conduit 58. And as shown in Fig. 6, the grooves 18 and 15 are respectively in communication with the power cylinder conduits 69 and 18. Consequently when the valve piston is in the left hand position as shown in Fig. 6, the action of the collars 61 and 68 will be to direct air under pressure from the intake conduit 58 into the power cylinder conduit 68. In this position of the valve piston no intake air under pressure will be admitted to the groove 15 or to the conduit 18. When the valve piston is in the right hand position, air under pressure from conduit 58 will be directed to power cylinder conduit 18 via passages 15a and groove 15. Thus it will be seen that by reciprocating the ,valve piston, intake fluid under pressure may alternately be directed to the grooves 13 and 15.

via grooves I4.

As indicated in Fig. 6 exhaust passages 12a and 12b are formed respectively at the left and right extremities of the bore 16. These exhaust passages are in communication with an exhaust chamber Ha and an exhaust conduit llb. In the position of the valve piston shown exhaust may pass from conduit 18 to conduit 'llb via groove 15, passages 15a, 12b, and chamber Ha.

In order to accomplish an automatic reciprocation of valve piston 51a and hence a similar reciprocation of piston 54, intake air under pressure is simultaneously directed to opposite extremities of the valve piston via conduits l1 and 18 (Fig. 7) which feed fluid respectively against the outer surfaces of pistons 64 and 65. The air pressure acting against each piston 64, 65 is alternately removed by alternately opening bleeder valves connected thereto. v

Suitable bleeder valves 19 and are provided respectively for the left and right chambers of the master control valve (Figs. 1 and 6), that is, the bleeder valve 19 is in communication with the chamber of piston 64 via a conduit 82, and the bleeder valve 80 is in communication with the chamber of piston 65 via a conduit 8|.

The bleeder valves are normally held closed by resilient means and are alternately opened whereby air pressure is alternately bled from the chambers of said pistons 64 and 65, thus producing a reciprocating movement of the valve piston.

The above mentioned bleeder valves 19 and 88 may be identical in construction. There is shown in Fig. 8 a bleeder valve of this type which is constituted by a valve body 84 having, for example, said conduit 8| attached to an inlet 85 and to an outlet 86. The passage of fluid through this valve is interrupted by a reciprocable valve piston arrangement 81 which may be constituted by a pair of rigidly connected valve plates 81a and 81b which are rigidly held in spaced relation by means of a valve rod 88. The latter preferably extends exteriorly of the valve body. The valve rod 88 is urged upwardly as shown in Fig. 8 by means of a suitable resilient coil spring 89. There may be mounted upon the end of the rod 88 a collar member 98 in threaded engagement therewith upon which a roller 9I may be mounted for a purpose to appear later.

When the valve piston 81 is in the position shown in Fig. 8 a flow of fluid through the bleeder valve is interrupted. When said piston is thrust downwardly in the direction of the arrow fluid may pass through the bleeder valve, through assages 92 and 93 which are formed within a cylinder 94 surrounding the valve piston 81. Said passages 92 and 93 are respectively in register with the inlet and outlet chambers 85 and 86.

In order to govern the speed of reciprocation of the piston 54 (Fig. 2) suitable valves may be interposed in the conduits 89 and 18 which are generically referred to as speed control valves and which are manually adjustable. Such a speed control valve 95 is illustrated in Fig. 9 and comprises a valve body 98 having an inlet 91 and an outlet 98. A partition 99 separates said inlet and outlet and has formed therein an orifice I89 having associated therewith, for example, an adjustable needle I8I for controlling the flow of fluid through said orifice. The position of needle I8I may be controlled in a conventional manner by adjustment of a handle I82 which through the intermediary of threads I8Ia controls the axial position of said needle.

A one-way exhaust valve is provided in the speed control valve consisting, for example, of a ball I83 which is normally urged to close a second orifice I84 formed in said partition 99. The ball I83 may be resiliently urged to close .orifice I84 by means of, for example, a coil spring Hi5. Said ball is situated on the inlet side of the partition 99 and is designed to permit a free flow of exhaust fluid in a direction opposite to the arrows shown in Fig. 9. Thus, the velocity and the pressure of inlet fluid to the cylinder 55 may be subjected to a fine adjustment. However, the speed control valves are not embarassed by the adjustment of the orifice I88 and needle I85 in so far as the flow of exhaust fluid is concerned. Consequently, if it is desired to move the piston 54 slowly in one direction, for example, to the left (Fig. 2), and rapidly to the right, this may be accomplished through the proper adjustment of the speed control valves.

The above described speed control valve 95 may be inserted in conduit 89. A similar valve MS may be inserted in conduit 18.

Speed of reciprocation may also be controlled by regulation of valve 6|.

As illustrated in Figs. 1 and 2, the above described bleeder valves 19 and 80 are alternately operated by means of, for example, a reciprocating ball I81 which is mounted upon the piston rod 54a. The piston rod 54a is, of course, attached to the piston 54 and preferably rests in a suitable journal I88 which assists in guiding same. The ball I81 is adapted for alternately striking and opening valves 19 and 88'.

The embodiment illustrated in Fig. is identitical to that shown in Fig. 1 with the exception that instead of employing mechanically operated bleeder valves as at 19 and 88 electrical means are provided for operating said bleeder valves. Such electrically operable valves I89 and I I8 are shown which are analogous to the bleeder valves 19 and 88.

The means for actuating the valve I89 constitutes in the form of a switch III which at one 8 I side thereof is connected by electrical leads II2 to said valve I89. The other side of switch III is connected by lead II: to one side LI of a source of electric energy. The solenoid valve I89 is connected by lead II3a to the other side L2 of said source of energy. A similar switch H4 is positioned near the switch III and is electrically connected to the valve H8 and lead II3 by means of leads 5 and H9 respectively. A lead lI3b connects solenoid valve II8 to L2.

Switches III and H4 are successively operated by the member I81. Suitable solenoids within the bleeder valves I89 and H8 thus may be actuated. Such solenoids control a valve structure analogous to that illustrated in Fig. 6.

In operation the device is set in motion by opening the gate valve 59, thereby permitting air to pass through the safety valve 68 and the pressure regulator GI and into the master control valve 51 by way of the conduit 58.

If the valve piston of the master control valve 51 is in the position shown in Fig. 6, fluid will flow into the groove 14 (Figs. 6 and '1) through the perforations 14a and into the chamber 15, and thence into the power cylinder conduit 69 via perforations 13a and groove 13. Thus air prcssure will be exerted upon the left hand side of the piston 54 (Fig. 2) and will urge same to the right. During the motion from left to right, air will be exhausted through the conduit 18 and will reach the exhaust conduit 1Ib by way of the groove 15, perforations 15a, passage 12!; in the cylindrical gate member 12, and chamber 1 la.

The motion toward the right of the piston 54 will continue until the ball I81 strikes the bleeder valve 88, temporarily to open same. The temporary opening of bleeder valve 88 will cause a sudden reduction in pressure in the right hand portion of the master control valve, that is, in the chamber of the piston 85. Consequently, air pressure acting upon the piston 84 will immediately thrust the valve piston to its right hand position opposite to that shown in Fig. 6 and movement of the piston 54 will be started in the opposite direction.

As above mentioned the speed of this reciprocation including the speed movement in any one direction may be closely regulated by the speed control valves 95 and I86.

The rods 38 which are held within the tray 39 are thus pushed or thrust one at a timefrom the discharge position within the barrel 48 into engagement with the roller 28 and belt 23. As soon as a rod 38 is engaged by said roller and belt, they urge same axially to the left as shown in Fig. 3, by virtue of the angular relationship of the axis of the roller 28 relative to the direction of motion of the belt. Thus there is an automatic withdrawal of each rod after itengages said roller and belt. After the pusher rod 48a has been withdrawn to the position shown in Fig. 2 and after each rod 38 has been moved atoaveo rods 38, the arms Sla, 52a, lowered, the charging tray moved back into alignment with the magazine tray and the operation of the apparatus will continue.

Although the above described device has been limited in the description to a so-called centerless grinder as exemplified by the roller 28 and the belt 23, it is possible to employ the novel feeding device with other types of apparatus which may act upon objects which are discharged from the magazine. For example, it may be possible to employ the above described novel feeding apparatus in conjunction with a simple rotating buffer. Y

While the invention has been described with respect to certain preferred embodiments, it will be understood by those skilled in the art after understanding the invention that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended therefore in the appended claims to cover all such changes and modifications.

What is claimed as new and is desired to be secured by Letters Patent is:

1. A paratus for automatically feeding sections of elongated stock of a preselected length, along a stationary guide'into centerless grinders, comprising in combination with sad guide: a centerless grinder means including a magazine for successively delivering sections of said stock onto said guide: a pneumatic pressure actuated, recinrocative p ston device, for feeding said sections longitudinally along said guide; a pneumatic pressure actuated control valve, including a reciprocative valve element, for supplying air under pressure to said piston device; a pair of passageways extending between said control valve and said piston device, for concurrently applying pneumatic pressure thereto and exhausting said pressure on opposite sides of said piston device, respectively, and in alternately reciprocal fashion; said passageways including adjustable speed control valve elements, for independently adjusting the rates of fluid flow through said passageways, and thereby the speed of actuation of said piston device, in opposite directions, respectively, each of said speed control valve elements being provided with a passage having therein a one way exhaust valve for by-passing its respective element whereby air exhausting through either one of the passageways interconnecting said control valve and said piston device is not restricted by the adjustable valve element; and valveactuating means responsive to preselected reciprocative displacements of said piston device, for reciprocatively actuating said control valve, thereby reciprocatively to actuate said piston device.

2. Apparatus for automatically feeding sections of elongated stock, of a preselected length, along a stationary guide, comprising: a centerless grinder, a pneumatic pressure actuated piston device, including a pusher rod secured to a piston reciprocatively displaceable within a cylinder having ports at opposite end thereof; a pneumatic pressure actuated, control valve comprising a valve element reciprocatively displaceable within a cylinder, the latter having centrally disposed pressure inlet and exhaust ports, together with additional exhaust ports at the opposite ends thereof, and also ports connected respectively to the said ports of said piston device; means for directing air under pressure to the opposite ends of said valve element cylinder, the displacement of said valve element occurring in response to 10 the opening of one of said additional exhaust ports; said valve element being displaceable in one direction in response to pneumatic pressure applied to said inlet port, to connect said inlet and central exhaust ports to said piston device ports, and being displaceable in the opposite direction to reverse said connections; valve means responsive to preselected reciprocative displacements of said piston device, alternately to open the end ports respectively of said control valve. whereby said control valve is reciprocatively actuated by fluid pressure applied to said inlet port, thereby toreciprocate said piston device, a pair of speed controlvalve elements associated with respective of the ports in the opposite ends of said cylinder of said piston device, one of said speed control valve elements having a relatively small ,oriflce for effecting a slow return stroke of said device, the other of said valve elements having a relatively larger orifice for effecting a relatively faster feeding stroke of said piston device; and a pair of one way by-pass exhaust valve means-associated with respective of said speed control valve elements for by-passing same with respect to exhaust flow.

3. In apparatus of the class described, the combination comprising: a through feed centerless grinder including a movable abrasive mem-\ her and a tiltable feed roller which remain in substantially fixed spaced relationship during operation; apparatus for continuously and automatically feeding rods into said grinder comprising: a downwardly extending magazine for gravity feeding a supply of said rods successively against a stationary guide; a fluid pressure actuated piston device for successively feeding said rods longitudinally along said guide, said device including a pusher rod secured to a piston displaceable within a cylinder having ports on opposite sides of said piston; means for reciprocatively actuating said piston, comprising a control valve having a reciprocative valve element within a cylinder, the latter having fluid pressure inlet and exhaust ports and ports connectable respectively to the ports of said piston device. said valve element being displaceable in one direction to connect its inlet and exhaust ports respectively to the opposite ports of said piston device, and being displaceable in the opposite direction to reverse said connections; and means actuatable by reciprocative movement of said piston device to reverse the displacement of said control valve element, whereby, in response to fluid pressure applied to said inlet port, said piston device is reciprocatively actuated under control of said valve.

4. In apparatus of the class described, the combination with a through feed centerless grinder having a movable abrasive member and a tiltable feed roller which remain in substantially fixed spaced relationship during operation thereof, including: apparatus for continuously and automatically feeding sections of elongated stock, of a preselected length, to said grinder along a stationary guide, comprising: means including a magazine for successively delivering sections of said stock onto said guide; a fluid pressure actuated, reciprocative piston device for feeding said sections longitudinally along said guide; a control valve, including a reciprocative valve element, for supplying fluid under pressure to said piston device; and valve actuating means actuatable by preselected reciprocative movements of said piston device, for reciprocatively actuating said control valve, thereby reciprocatively to actuate said piston device.

5. Apparatus for continuously and automatically feeding sections of elongated stock, of a preselected length, along a stationary guide, comprising in combination with said guide: means including a magazine for successively delivering sections of said stock onto said guide; a fluid pressure actuated, reciprocative piston device for feeding said sections longitudinally along said guide; a control valve, including a reciprocative valve element, for supplying fluid under pressure to said piston device; valve actuating means actuatable by preselected reciprocative displacements of said piston device, for reciprocatively actuating said control valve, thereby reciprocatively to actuate said piston device; and a through feed centerless grinder for engaging such sections seriatim and urging same axially out of said guide, said grinder having a movable abrasive member and a tiltable feed roller which remain in substantially flxed spaced relationship during the action thereof on such sections.

6. Apparatus for continuously and automatically feeding sections of elongated stock, of a preselected length, along a stationary lide, comprising in combination with said guide: a through feed centerless grinder adapted for engaging such sections seriatim and urging same along such guide, said grinder including a moving abrasive member and a feed roller which remain in fixed spaced relation during the action thereof on such sections; means including a magazine for successively delivering sections of said stock onto said guide; a fluid pressure actuated, reciprocative piston device, for feeding said sections longitudinally along said guide; a fluid pressure actuated control valve, including a reciprocative valve element, for supplying fluid under pressure to said piston device; a pair of passageways extending between said control valve and said pis ton device, for concurrently applying fluid pressure thereto and exhausting said pressure on opposite sides of said piston device, respectively, and

in alternately reciprocal fashion; said passage- 45 ways including adjustable valve elements, for independently adjusting the rates of fluid flow through said passageways, and thereby the speed of actuation of said piston device, in opposite directions, respectively; and valve actuating means responsive to preselected reciprocative displacements of said piston device, for reciprocatively actuating said control valve, thereby reciprocatively to actuate said piston device.

'7. In apparatus of the class described, the combination with a through feed centerless grinder having a movable abrasive member and a tilted feed roller which remain in substantially fixed spaced relationship during operation thereof, including: apparatus for continuously and automatically feeding sections of elongated stock of a preselected length to said grinder along a stationary guide, comprising: means including a magazine for successively delivering sections oi said stock onto said guide; a reciprocative piston device for feeding said sections longitudinally along said guide; a control valve for said piston device; and valve actuating means actuatable by preselected reciprocative movement of said piston device, for controlling said valve, thereby reciprocatively to actuate said piston device.

CARL J. MURRAY. WALLACE K. LOWE.

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

UNITED STATES PATENTS Number Name Date 1,733,097 Holmes Oct. 22, 1929 1,892,453 Fuller Dec. 27, 1932 1,938,766 Hopkins Dec. 12, 1933 2,086,052 Silven July 6, 1937 2,147,891 Graf et al. Feb. 21, 1939 2,260,843 Strong Oct. 28, 1941 2,295,342 Graf et al. Sept. 8, 1942 2,320,039 Jobert May 25, 1943 2,377,982 Theber et al. June 12, 1945 OTHER REFERENCES Ingenious Mechanisms for Designers and Inventors, by Franklin D. Jones, 1st edition, 1930, The Industrial Press, New York, pages 475-476.

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