US2184172A - Dispensing device - Google Patents

Description

Dec. H9, 1939. w. M VENABLE 2,184,172

DISPENSING DEVICE Filed March 24, 1958 Patented Dec. 19, 1939 UNITED STATES PATENT vOFFiQii DrsrsNsiNG DEVICE Application March 24, 1938, Serial No. 197,839

6 Claims.

rThis invention relates to a dispensing device and, in particular, to a device for use in centralized lubricating systems to dispense fluid or semiiiuid materials such as lubricants.

The invention operates on a principle similar to that of known devices wherein the delivery or material underpressure to an inlet effects ay dispensing operation, fills a measuring chamber and, on release of the pressure on the material, causes the measured amount to iiow from the measuring chamber to a position ahead of a discharge piston for subsequent dispensing. Devices of this kind which have been known heretofore have been characterized by relatively large size and somewhat costly construction. It is an object of this invention to improve upon such devices by providing a compact dispenser which can be manuiactured at relatively low cost.

According to the invention, a dispenser including a cylinder and a piston reciprocable therein is adapted for operation as above explained by the pro-vision of a control valve and connecting passages in the discharge piston itself. In a preferred form, a piston reciprocable in a-cylinder has an axial bore in which a piston valve is movable. Passages intersecting the bore permit material delivered to an inlet communicating with the cylinder to iiow into the space behind the piston, thereby causing a discharge or ejecting stroke of the latter. Vlfhen the pressure applied to the material is released, the piston valve is restored to its normal position thereby establishing a by-passing passage for the material forced into the cylinder behind the piston which thereupon flows through the piston to the other side thereof and is then ready to be ejected on the next stroke. It will be understood that devices of the character to which the invention relates are operated only at intervals, depending upon the lubricating demands of the machinery with which the device is associated. The bore in the piston is axial in one form of the invention and transverse in a modification. These forms are shown in the accompanying drawing in which:

Fig. 1 is a longitudinal central section showing the parts in their normal positions;

Fig. 2 is a similar view showing the parts in their measuring and discharging positions;

Fig. 3 is a similar view showing the parts in their by-passing positions;

Fig. 4 is a similar View of a modification showing the parts in their normal positions; and

Fig. 5 is a transverse sectional View taken along the line V--V of Fig. 4, with the parts in the dotted line positions.

Referring now in detail to the drawing, the device comprises a body Ill having a bore with piston II reciprocable therein. The ends of the bore are closed by plugs I2 and I3. The plug I2 has a hole therethrough and is adapted to receive 5 a connection Ill extending to the machine part or other apparatus to be lubricated. An adjusting screw I5 is threaded through the plug i3 and is provided with a lock nut I6.

The piston II has an axial bore Il there- 10 through, one end of which is closed by a plug iB.

A compression spring I9 bearing against the plug I2 and the piston I I normally urges the latter to the right until the plug I8 engages the screw A piston valve 2E! is reciprocable in the bore il 15 and is normally urged against the plug I8 by a compression spring 2l. The spring ZI bears against a transverse pin 22 extending across the piston adjacent the open end thereof.

An inlet 23 communicating with the body lll is 20 adapted to be connected to any convenient source of the material to be dispensed. An recess 2li formed in the piston communicates with the inlet in all positions of the piston. A passage 25 connects the recess 2li with the closed end of 25 the bore II. A passage 26 extends inwardly from the end of the piston II and intersects the bore Il at a point therein beyond the valve 25.1 when the latter is in the normal position.

The operation of the device will now be ex-30 plained with reference to Figs. 2 and 3 illustrating the relative positions of the parts at successive stages of a complete operating cycle. When the parts are in the positions illustrated in solid lines in Fig. l, material such as a semi-fluid lubricant 35 delivered under pressure to the inlet 23 fills the recess 24 and flows through the passage 25 into the bore I'I behind the piston valve 2l). The latter is provided with a projecting stop portion 2l' which insures ample clearance between the bodyT 40 of the piston valve and the end of the bore to admit material behind the former. As the material flows into the bore II, the piston valve 2li is displaced from the position shown in solid lines to the dotted line position of Fig. l. Such v movement of the valve 20 uncovers the intersection of the passage 26 with the bore I'I, permitting material to flow through the former int-o the bore in the body I0 behind the piston I I. The piston I I is thus caused to effect a discharge or ejecting stroke, as illustrated in Fig. 2. by the pressure of the material delivered into the right hand end of the body I0 in the manner alreadyT described. As will become apparent shortly, the end of the body I0 adjacent the discharge connec- 55 tion I4 is normally filled with the material being dispensed whereby the piston II displaced from the left hand end of the body precisely the amount of material delivered into the right hand end thereof. The right hand end thus serves as a measuring chamber while the left hand end constitutes a storage chamber preparatory to a succeeding ejecting stroke of the piston I I.

The ejecting movement of vthe piston II is limited by the collapsed length of the spring I9 although any other suitable means may be employed for this purpose. Fig. 2 shows the relative positions of the parts when the piston I I has reached the limit of its movement. When the piston has reached this position, the discharge of material through the connection I4 is terminated, even though pressure is maintained on the material entering the inlet 23. As soon as this pressure is relieved, however, the piston valve 2D is restored to its normal position relative to the piston II by the spring 2|. The material displaced by the restoring movement of the piston valve flows outwardly through the passage 25 and inlet 23. The spring 2| must be strong enough relative to the force exerted by the spring I9 to restore the piston valve 29 to its limiting right hand position before the spring I9 is eiective to resto-re the piston II. As soon as the piston valve 2l) has reached its limiting right handposition a direct by-pass is provided through the passage 26 and the bore II for the material behind the piston II. The spring I9 is then effective to restore the piston II causing the material behind the piston to be displaced through the by-passing passage to the left hand end of the body Ill for discharge upon a subsequent operation. The positionsI of the parts during the restoring movement are as shown in Fig. 3. The screw I5 determines the initial position of the piston II and thereby controls the amount of material discharged at each operation of the device. Figs. 2 and 3 merely show how the recess 24 maintains communication with the inlet 23A in all positions of the piston I I.

Dispensing devices such as shown and described may be used in such numbers as required to deliver lubricant to various machine elements. A number of the devices may, therefore, conveniently be embodied in a unitary casting and may have a common connection to the lubricant supply with separate connections from each device to the element to be lubricated thereby.

A modified construction is shown in Figs. 4 and 5. This form includes a cylinder 30 having one closed end provided withr a discharge connection 3l. 'Ihe other end of the cylinder is closed by a cover 32 having an adjusting screw 33 threaded therethrough corresponding to the screw I5. An inlet connection 34 communicates with an annular groove 35 formed in the wall of the cylinder.

A piston 36 is reciprocable in the cylinder and is normally maintained against the screw 33 by a spring 3'I. A passage 38 in the piston maintains communicationr with the inlet 34 in all positions of the piston.

A transverse bore 39 is formed in the piston and a piston valve 40 is reciprocable therein, being normally urged toward the retracted position shown in solid lineslby a spring 4I. As shown, the valve 40 normally overlies the port 42 connecting the bore 39 with the right hand end of the cylinder 30. A bore 43 through the piston connects the opposite ends of the cylinder when the valve 40 is in its normal position.

The operation of the modification shown in 'Figs 4 and 5 will probably be apparent from the description of the device shown in Fig. 1 but will be briey reviewed. When material such as a semi-Huid lubricant is delivered through the inlet 34 under pressure, the piston valve 4U is first displaced to the A'dotted line position to uncover the port 42 thereby admitting the material to the right hand end of the cylinder 30. This causes displacement of the piston 36 and any material which may previously have been fed into the left hand end of the cylinder, as the valve 4I) closes the passage 43 when displaced. When the pressure on the former and the latter is maintained by the groove 35 regardless of angular movement of the piston within the cylinder.

It will be apparent from the foregoing description vthat the invention lprovides a simple and compact form of dispenser which is particularly adapted for the delivery of a measured amount of material such as a semi-fluid lubricant by the simple expedient of applying pressure to a supply of the material connected to the device. Both forms of the invention shown are very simple and compact and may be manufactured at relatively low cost since the parts are such as to require only the simplest machiningoperations. At the same time, the device is sturdy in design and characterized by a long,

useful life without requiring any substantial maintenance or adjustment.

Although I have illlustrated and described herein but a preferred form of the invention and a modification, changes in the structure shown may be made Without departing from the spirit of the invention or the scope of the appended claims.

I claim:

l. A' device for dispensing a measured quantity of material comprising a cylinder, a piston reciprocable therein, means normally urging said piston toward one end of said cylinder, a bore in said piston communicating with said cylinder and a piston valve reciprocable in said bore,

means normally urging said valve toward one end of said bore, an inlet for said cylinder, a passage in said piston communicating with said inlet and with said bore at a point such that pressure 'applied to said inlet causes the piston valve to be displaced, and means providing a passage in said piston adapted on advance movement of said valve to admit material behind said pistor to cause movement thereof in opposition to said iirst mentioned means, and on retraction of said i displace material in the cylinder, means normally urging the piston toward one end of the cylinder, a bore in the piston and a Valve therein, means normally urging the Valve toward one end of the bore, an inlet for said cylinder, a passage in the piston communicating with said inlet and said bore in such manner that material under pressure delivered to said inlet displaces the valve, and passages in the piston adapted on displacement of the Valve to admit material behind said piston and on retraction or" the Valve to by-pass material through the piston for a subsequent discharge thereby.

3. A dispensing divecie comprising a cylinder, a discharge port communicating with one end oi the cylinder, the other end being closed, a piston reciprocable in said cylinder, means normally urging the piston toward the closed end of the cylinder, a bore in said piston, said bore being closed at one end thereof, the other end of the bore communicating with the cylinder, a piston valve in said bore, means normally urging the valve toward the closed end of the bore, an inlet communicating With said cylinder, a passage in said piston connecting said inlet with the closed end cf said bore, and a passage in said piston connecting the closed end of the cylinder to said bore at a point beyond said valve when the valve is in normal position.

4. A dispensing device comprising a body having a bore therein, a discharge port communicating with one end of the bore, the other end being closed, a piston reciprocable in said bore, means normally urging the piston toward the closed end of the bore, a bore in said piston, said piston bore being closed at one end thereof, the other end of the piston bore communicating with the rst-mentioned bore, a Valve reciprocable in the bore in said piston, means normally urging the Valve toward the closed end of the piston bore, an inlet communicating with said rst-mentioned bore, a passage in said piston connecting said inlet with the closed end of said piston bore, and a passage in said piston connecting the closed end of the first-mentioned bore to said piston bore at a point beyond said valve when the valve is in normal position.

5. A dispensing device comprising a body, a piston reciprocable in a bore in said body and effective on a forward stroke to deliver material disposed ahead of its forward face, under the pressure of material supplied behind its rear face, means normally urging said piston toward its retracted position, an inlet in said body communicating with said bore, a bore in said piston, a valve reciprocable in said piston bore, means for normally urging `said Valve toward one end of said piston bore, a passage in said piston connecting said inlet with said end of said piston bore, a second passage in the piston connecting the rear end of said rst-mentioned bore with said piston bore at a point ahead of the valve when the latter is retracted to said end of its bore whereby material supplied to said inlet displaces the Valve against the force exerted by said second-mentioned means, said passages being efective on displacement of the Valve to admit material from said second-mentioned bore to the rear face of the piston and, on restoration of said valve to said end of its bore, to by-pass material from behind the rear face of the piston to the space ahead of the forward face.

6. Apparatus for dispensing a measured amount of iiuid comprising a cylinderhaving an outlet adjacent one end, a piston reciprocable in said cylinder for discharging material by a forward stroke in the cylinder, means urging said piston toward a normal position near the rear end of the cylinder, an inlet in the side of the cylinder, a bore in said piston, a piston valve reciprocable in said bore, means normally urging said Valve to a retracted position, means connecting said inlet to said bore whereby the pressure applied to uid in the inlet is eiective to displace the piston valve from its retracted position, means in said piston providing a passage connecting the inlet to the rear end of said cylinder which is closed by said valve in its retracted position, and means providing a by-passing passage through said piston which is closed when said valve is displaced.

WILLIAM M. VENABLE.

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