KR20010092359A - Fluid pump dispenser having product retraction feature - Google Patents

Abstract

PURPOSE: A fluid pump dispenser is provided to avoid the formation of product droplets at the end of each pressure stroke, thereby avoiding messy conditions and minimizing contact between product and the outside air at the spout end which causes clogging. CONSTITUTION: A fluid pump dispenser(10) of the loss motion piston type provides for maintaining discharge ports open a slight interval at the commencement of each plunger upstroke while a pump chamber(21) expands to retract product from a discharge passage(13) into the chamber to thereby avoid the formation of product droplets at the exit end of a discharge spout(12). Such is effected by reducing the friction force acting between a piston(18) and a pump cylinder(16) relative to the friction force acting between the piston and a stem(11). An inlet valve assembly has a portion lying in the path of the piston which portion is connected by spring legs to a valve portion such that the restoring force of the spring legs shifts the piston together with the stem at the commencement of the plunger upstroke which maintains the discharge passage in open communication with the chamber.

Description

FLUID PUMP DISPENSER HAVING PRODUCT RETRACTION FEATURE}

This application is related to US Pat. No. 6,045,008, issued April 4, 2000, which is widely accepted.

The present invention generally relates to a manually operated fluid pump dispenser mounted with a hollow piston over a hollow stem for relative sliding movement during piston reciprocation in the pump cylinder opening and closing the discharge through the stem. In particular, the present invention constricts the discharge into the pump chamber at the start of each piston return stroke to prevent the discharge at the outlet from dripping or dripping. This emission shrinkage feature is achieved by deformation of the pump cylinder without the need for additional parts, resulting in significant savings in assembly operation and significant costs associated with dispenser production.

As described in the above-mentioned related patent, an annular piston having a center hole is mounted to the hollow stem of the pump plunger for reciprocating movement in a pump cylinder composed of a variable volume pump chamber together with the pump piston. A valve controlled inlet passage leads into the chamber and consists of a hollow stem and forms a terminal end at the outlet outlet through which the valve controlled inlet passage is located away from the pump chamber. This piston is mounted on the stem for relative sliding movement during pumping to open and close the discharge port to the discharge passage.

The frictional force acting between the piston and the bore wall of the pump cylinder is generally greater than the frictional force present between the inner diameter wall of the annular piston and the opposing outer wall of the plunger stem. Thus, during each pressure stroke, the manipulator depresses the plunger against the return spring force, so that the difference in friction force causes the plunger stem to be determined in conjunction with a stop acting between the piston and the stem prior to the piston. Move the given distance.

At the start of the piston return stroke, the plunger stem moves upwards under the action of the biasing force of the return spring prior to the piston movement, due to the high friction force acting between the piston and the cylinder versus the friction force acting between the piston and the stem. Thus, whenever the piston engages with the valve element at the bottom of the stem, the outlet port is closed to raise the piston during the return stroke with the plunger and its stem. The piston moving during the return stroke leads the discharge into the pump chamber to reduce the internal pressure below atmospheric pressure and allow the discharge to be withdrawn from the inlet passage through an unsecured check valve and to reprime the pump. During the pump chamber repreparation operation, the discharge valve is closed while the inlet valve is open.

It is an object of the present invention to improve the manual pump dispenser of the type described above by relatively moving the annular piston which opens and closes the discharge port through the stem through the stem during the pressure and suction stroke.

1 is a vertical sectional view of a fluid pump dispenser incorporating an embodiment according to the present invention,

FIG. 2 shows the plunger stem and piston at the end of the downstroke similar to FIG. 1; FIG.

3 shows the piston and stem after the start of an upstroke similar to that of FIG. 2, FIG.

FIG. 4 shows the piston and stem during uptravel after the start of upstroke similar to FIG. 2;

FIG. 5 shows another embodiment according to the invention showing a piston and a stem at the end of a pressure stroke similar to FIG. 2, FIG.

6 shows the piston and stem at the start of an upstroke similar to FIG. 5;

7 shows the discharge valve in a closed condition after the start of an upstroke similar to that of FIG. 5, FIG.

FIG. 8 shows the piston and stem during upward travel after the start of an upstroke similar to FIG. 5.

The discharge shrinkage feature according to the present invention has been developed by a unique deformation of the pump hole, which causes the discharge shrinkage into the pump chamber, thus preventing the formation of droplets of discharge at the discharge outlet. Provision of such a feature can avoid any increase in the overall price of the dispenser by simply reconfiguring existing parts without the need for additional parts. The adoption of the pump dispenser according to the invention for shrinkage of the discharge is very effective and economical despite the simple and simple process.

At the start of each piston return stroke in accordance with the present invention, the annular piston is initially moved out of the pump hole with the plunger stem to open the discharge port so that the discharge passage passes through the currently expanded pump chamber under pressure. The pressure reduction while the discharge keeps open at short intervals shrinks the discharge from the discharge passage into its expansion pump chamber, thereby preventing the formation of unobtrusive and unwanted discharges at the outlet end of the discharge passage.

According to the invention, at the bottom of the cylinder, an interference fit between the piston and the pump cylinder wall is provided at the bottom of the cylinder to reduce the frictional force acting between the piston and the pump cylinder wall, the wall of the center hole of the annular piston and the peripheral plunger. Adjust below that of the friction force present between the stems. This allows the stem to move with the piston at the start of the plunger return stroke, so that the discharge is in the open position for a short interval of piston return. Since the discharge passage is open with the expansion pump chamber, the negative pressure generated by the expansion chamber pushes the discharge from the discharge passage into the chamber and simultaneously pushes the discharge into the chamber through the inlet passage. Accordingly, there is an effect of retracting the discharge inwardly away from the exit end of the discharge path.

According to another embodiment of the invention, the inlet valve is in the path of the reciprocating motion of the piston, restoring the spring means oblique in the direction of the reciprocating motion. Therefore, at the end of each pressure stroke, the piston exerts a strong impact on its spring means to move the piston with the plunger stem to open the discharge during the subsequent return stroke, and the expansion pump chamber for short intervals. It will work. Therefore, the negative pressure generated by the expansion pump chamber serves to draw the discharge from the discharge passage into the pump chamber and the discharge through the inlet passage into the pump chamber. This constricts the discharge away from the terminal end of the discharge to prevent dripping or dripping of any droplets there.

Other objects, advantages and novel features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.

In the drawings, the same reference numerals refer to the same and corresponding parts in the entire part of the drawings, the fluid dispenser according to an embodiment of the present invention is generally shown in FIG. 1 to 10, and the like, It is disclosed in the referenced US patent application Ser. No. 09 / 217,239, as it comprises a pump plunger having a hollow plunger stem 11 extending to an outlet pipe 12 at the top and equipped with a discharge passage 13. The surrounding skirt 14 has a pump cylinder 16 where it is mounted to mount the dispenser against a container (not shown) of the discharge to be discharged by a closure cover 17 which is internally threaded. It is configured to interlock with and interlock with an inner liner 15 fixed inside the upper end of the pump body. The plunger is shown in the locked position up in FIG. 1 and can be locked in the plunger lock-down position as described in detail in the above-mentioned application. Likewise, the present invention is configured to be integrated into the dispenser without such plunger lock-up or lock-down features and without departing from the scope of the present invention.

The hollow annular piston 18 having the center hole 19 is mounted on the lower end of the plunger stem for reciprocating together with the plunger in the pump cylinder and has a variable volume pump chamber 21. Likewise, this piston is mounted on a relative sliding plunger stem during manual reciprocation. To this end, the inner end of the stem tightens the shoulder 22 spaced from the opposing inner shoulder 23 configured at that position in the position where the plunger shown in FIG. 1 is fully raised. The plunger return spring 24 is an internal flange of the liner 15 with a suitable rib 25 of the inner surface of the plunger skirt 14 or the like so as to bounce the piston obliquely in the rest position of FIG. 1. It extends between 26.

The valve element 27 is fixed to the inner end of the plunger stem, which element 27 has a central hole at the end of the retracted plunger stem to make a hole 33 free of obstruction, as shown at the lower terminal end of the stem. 29) a pair of upright legs 28 fixed by press or otherwise secured.

Further, the valve element 27 is provided with an upwardly open annular groove 31 (FIG. 2) having a valve seat for accommodating the annular valve flange 32 suspended from the piston.

The communication between the pump chamber 21 and the discharge passage 13 seals between the valve flange 32 and the valve seat 31 so that the discharge port 33 is closed at the stop and / or up-lock position of the plunger. Adjust the valve to close due to the engagement. In addition, the upright annular flange 34 of the piston has an open annular groove 45 for accommodating an annular seal 36 suspended from the inner flange 26 of the liner 15. Thus, the leakage of discharge from the pump chamber is prevented under the conditions of FIG. 1.

At the end of the plunger down stroke and in the lock down position of the plunger, as shown in FIG. 2, the annular flange 37 suspended above the element 27 is engaged with a seal in an upstanding flange 38 at the bottom of the pump cylinder. And a general dip tube in which the dispenser extends into the vessel (not shown) and the inlet passage 41 is configured in a pump chamber controlled by an inlet ball check valve 42 or others of that kind. (dip tube) 39 is suspended at the bottom of the cylinder.

In operation, the downward manual pressure applied to the plunger without the plunger locked in the up position of FIG. 1 is released from the valve flange 32 which the shoulders 22 and 23 contact and open the discharge port 33. The stem 11 is initially moved relative to the piston 18 until it is moved. The downward pressure applied continuously to the plunger then contributes to the reciprocating movement of the piston in the cylinder to compress the discharge during the plunger reciprocating movement located in the pump chamber and likewise to discharge at the end of the tube 12 through the discharge passage. During each successive upstroke of the plunger by being made by the recovery force of the return spring, the pump chamber expands and the discharge is drawn into the pump chamber through the open inlet passage at the negative pressure generated therein. As in any general method, a ball cage may be provided in the throat of the pump cylinder to limit the movement of the ball valve from its seat.

In general, the “lost motion” formed between the plunger and the piston during its pressure and return stroke may cause the valve flange 32 to displace the valve flange 32 in consideration of the return of the stem from the end of the plunger downstroke prior to the piston. ), Close the discharge port and make a piston return with the plunger to the FIG. 1 position. The discharge port is closed after being formed in the discharge end of the tube at the end of the plunger downstroke during the plunger reciprocation between the pressure and the return stroke, as a droplet of discharge described above. This droplet formation is unclear since it represents undesirable conditions of the operator.

The discharge port 33 according to the invention keeps the opening open for a short interval at the start of the plunger return stroke and expands the pump chamber, opening between the discharge passage and a condition shallower than the air velocity of the expanded pump chamber. The discharge port is closed after a small amount of discharge is retracted from the discharge bin into the pump chamber. This contraction causes the discharge to be sucked into the discharge end of the tube to prevent the formation of droplets of discharge in the tube at the end of the plunger downstroke as before.

During plunger downstroke, the friction force acting between the piston seals 43 and 44 and the inner wall of the pump cylinder is less than the friction force acting between the wall of the center hole 19 of the piston and the outer wall 45 of the retracted cross section of the plunger stem. Big. This allows the stem to move in proportion to the piston as determined by the stops 22, 23 during the plunger downstroke. Then, at the start of the plunger upstroke, the outlet is closed as the friction force shown between the piston seal and the pump cylinder wall is greater than the friction force shown between 19 and 45 which causes opposite movement, ie the plunger return slightly ahead of the piston return.

The inner diameter d of the pump cylinder at its bottom end section 46, according to one embodiment of the invention shown in FIGS. 1 to 4, is slightly larger than the standard inner diameter D of the pump cylinder for the rest. At this time, the inner diameter d does not affect the sealing property between 43 and 44 and the pump cylinder inner wall at the end of the piston downstroke, as shown in FIG. In order to reduce the frictional force, the reduced frictional force is less than the frictional force existing between the outer wall 45 and the wall of the central hole 19 of the piston.

This variable interference between the piston and the inner wall of the pump cylinder facilitates the return movement of the piston with the stem at the start of the plunger upstroke from the Figures 2-3. With a greater frictional force established between 45 and 19, which exceeds the frictional force established between the seals 43 and 44 and the inner wall of the pump cylinder in its cross section 46, the piston is returned with an instantaneous plunger return The discharge port 33 is opened so that it opens in an open state between the pump chamber 21 and the discharge passage 13. This discharge open condition established during pump chamber expansion causes a small amount of discharge to contract from the discharge passage into the pump chamber, thereby preventing the formation of droplets at the end of the discharge pipe, while at the same expansion pump chamber volume, an inlet ball check valve that is not fixed. The suction of the discharge from the inlet passage is started through. If the plunger seal 44 reaches the inner diameter D cross section of the cylinder, as shown in Fig. 4, the friction force existing between the wall 45 at the retracted portion of the stem and the wall hole 19 of the piston is small. The greater friction between seal 44 and the inner wall portion of the cylinder as compared to the recording results in a relative movement of the plunger relative to the piston, so that the pump chamber volume continues to expand and draw emissions from the inlet passages, as in the conventional method. Reread.

The inner diameter D of the pump cylinder according to another embodiment of the present invention shown in FIGS. 5 to 8 has a constant overall length, and the inlet ball check valve is adapted to control the inlet passage 41 with the valve as shown in FIG. 5. To the throat 49 of the inlet passage 41 to an inlet valve assembly 47 such that a partial spherical 48 is provided. The inlet valve assembly 47 further comprises an upstanding annular wall 49 which is essentially connected with the part 48 via a plurality (two or three or more) spring legs 51. This wall 49 has outer projections 52 axially spaced to set the range of movement of the wall 49 relative to the projections 53 constructed on the inner wall of the pump cylinder.

In operation, the piston seal 43 at the end of the plunger downstroke supports the annular wall 49 of the valve assembly 47 in its path, and the rigid seal between its partial spherical portion 48 and its valve seat. The wall 49 is moved slightly downward by deforming the spring leg 51 which constitutes this. As such, in the plunger lock-down condition, as disclosed in the above-mentioned related application, any leakage of effluent through the inlet passage is prevented during filling and storage.

As shown in FIG. 6, at the start of the plunger return stroke, the plunger stem begins its return by the return force of the return spring 24 as in any conventional manner. With the provision of the valve assembly 47 as described above at the start of the return stroke, the restoring force of the spring leg 51 moves the wall 49 upwards correspondingly moving the piston upwards with the stem movement, and discharges. The port 33 is kept open and the valve flange 32 remains open between the discharge passage 13 and the pump chamber for a short interval since it is not fixed from the groove 31. This open condition exists during the expansion of the volume of the pump chamber, thereby constricting the discharge from the discharge passage into the pump chamber and eliminating any droplet formation of any discharge at the end of the conduit, while simultaneously entering the pump chamber through the inlet passage. Relieve the pressure of the spring 51 against the portion 48 taking into account the beginning of the sucked discharge.

As shown in Fig. 7, if the spring legs 51 have been restored to their original shape, only the force acting on the piston is due to the friction acting between the piston seals 43, 44 and the inner wall of the pump cylinder. With this friction force greater than the friction force formed between the 45 and the wall of the center hole 19 of the piston, the plunger stem in this stage continues the upstroke movement relative to the piston, so that the outlet portion of the valve flange 32 It is sealed and closed by being fixed again in the groove 31. As the upstroke continues, the pump chamber further increases in volume from that of FIG. 7 to that of FIG. 8 so that the pump chamber has a partial spherical valve portion 48 that allows the discharge to enter the pump chamber through the inlet passage. The spring 51 pressure is released. The combination between protrusions 52 and 53 limits the movement of the valve and likewise keeps the valve assembly in place during assembly of the parts of the dispenser.

It can be seen from the above that, despite its simple and economical construction, a very effective configuration, which avoids the formation of droplets of emissions at the end of each pressure stroke, prevents many dirty conditions and prevents emissions and movements. To minimize contact between the outside air in the

In view of the foregoing, many other variations and variations of the present invention are possible. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims (10)

Discharge liquid discharge through the discharge channel at the other end of the stem from one end of the hollow stem having a discharge passage through it and manually reciprocating between pressure and return stroke in the pump cylinder constituting the variable volume pump chamber Limiting relative sliding movement between the piston mounted on the one end and the valve-controlled inlet passage through the chamber and the discharge open and closed positions between the stem and the piston for manual sliding movement during manual reciprocation. Means for actuating, a valve element of said one end of said stem sealingly engaged with said piston in a discharge closed position, a first interlocking surface acting between said one end and said piston to form a first frictional force, and said piston And the second frictional force acting between the cylinder A second interlocking surface, the first frictional force exceeding the second frictional force at the start of a return stroke such that the piston expands and moves the pump chamber with the stem in the discharge open position and the discharge passageway. And shrink the discharge from the tube into the pump chamber to prevent the discharge from dripping from the tube. The method of claim 1, And a cross section of the pump cylinder forming one of the second interlocking surfaces has an inner diameter of a predetermined size larger than an inner diameter of the remaining cross section of the cylinder. An extended reciprocating hollow piston stem having an outlet passage having an outlet of the outer stage and a valve element of the inner stage, and a relative sliding movement between the discharge opening position and the discharge closing position in which the valve element is in engagement with the piston by sealing; A hollow piston mounted to the retracted end face of the piston stem at the inner end, wherein the piston is reciprocally movable in a pump cylinder to form a variable volume pump chamber, the hollow piston having a surface Having a central hole interlocking to form a first frictional force, the piston interlocking with an inner surface cross section at the inner end of the cylinder to have a annular piston seal to form a second frictional force, the first frictional force being the second The piston moves with the stem to exceed the friction force to open the discharge Increasing the volume of the pump chamber in position, the discharge shrinks into the chamber from the discharge passageway and the outlet to prevent dripping of the discharge from the opening. The method of claim 3, wherein And the inner surface cross section has a diameter of a predetermined size larger than an inner diameter of the remaining cross section of the cylinder. A closed volume discharge with a variable volume pump chamber at one end of the hollow stem capable of reciprocating between pressure and return stroke in the pump cylinder, with an open discharge position through the stem and a piston sealed against the valve element at the end of the stem. A hollow piston mounted on the retracted end face of the stem for relative reciprocation between positions, and an inlet valve assembly located on the bottom wall of the cylinder in the direction of the reciprocation of the piston, with a recovery spring means oblique in the direction of reciprocation An inlet passage through said chamber controlled by said spring means, said spring means being compressed by said piston at the end of said pressure stroke such that said piston moves away from said bottom wall at the beginning of said return stroke to open said discharge Volume of the pump chamber in position Increases, and thereby from the discharge passage formed by the hollow stem contracting the effluent from the outlet at the end of the passageway the fluid pump dispenser, characterized in that to prevent the dripping from the opening to the effluent. The method of claim 5, And said spring means comprise at least opposite pairs of spring legs lying along the inner wall of said cylinder. The method of claim 5, And said inlet valve comprises a partial spherical portion integrally formed with said spring means. The method of claim 6, And the inlet valve includes a partial spherical portion integrally formed with the spring leg. The method of claim 5, And said spring means cooperate with means provided in said cylinder for retaining said spring means in said bottom wall of said cylinder. The method of claim 6, And the spring leg cooperates with a means provided in the cylinder to retain the spring means in the bottom wall of the cylinder.