Pump for dispensing a fluid product

Abstract

The invention relates to a pump comprising a pump body (1) defining a sliding shaft (11), an actuating rod (2) movable in the pump body (1), a plunger (3) mounted on the actuating rod (2) and sealingly sliding in the sliding shaft (11) within a stroke of the plunger, the plunger (3) being formed with a lower lip (31) and an upper lip (32), a collar (4) fixedly mounted in the pump body (1), and a return spring (5) forcing the plunger (3) against the collar (4) in a rest position, wherein the sliding shaft (11) defines a main section (111) and a secondary section (112), the diameter of the main section (111) being smaller than the diameter of the secondary section (112), and wherein the lower lip (31) is in contact with the main section (111) within the stroke of the plunger, whereas the upper lip (32) is located at the level of the secondary section (112) in the rest position and is in contact with the main section (111) at least at the end of the stroke of the plunger, the invention being characterized in that the upper sealing lip (32) is in contact with the secondary section (112) in the rest position and that the plunger (3) is in sealing contact with the collar (4) in the rest position only via the sealing upper lip (32) of the plunger.

Description

Technical Field

[0001] This invention relates to a pump for dispensing fluid products, comprising a pump body internally defining a sliding cylindrical portion. The pump also includes an actuator rod movable back and forth within the pump body and a plunger mounted on the actuator rod and capable of sliding sealably within the sliding cylindrical portion during the plunger's stroke. The plunger has a lower sealing lip and an upper sealing lip. The pump further includes a collar fixedly mounted in the pump body and a return spring that forces the plunger against the collar in the pump's rest position. This is a conventional design for manual pumps used in the perfume, cosmetic, pharmaceutical, and food industries. Background Technology

[0002] The sliding cylindrical section is approximately cylindrical along its entire height, with a constant diameter, ensuring that both sealing lips are permanently subjected to constant radial stress not only during the plunger's stroke but also in the resting position, where the plunger rests against the raceway under the action of the return spring. This constant radial stress also implies significant constant friction, which reduces the support force of the plunger against the raceway and thus affects the seal quality between the two components in the resting position. Furthermore, if the raceway is not fully centered within the sliding cylindrical section—a situation that is not uncommon—plunge deformation can occur, potentially leading to leakage in the sliding cylindrical section, the raceway, or both. And because the pump is stationary, leakage of the fluid product can be significant. Summary of the Invention

[0003] The purpose of this invention is to ensure a complete seal of the pump when it is stationary.

[0004] To this end, the present invention proposes that the sliding cylindrical portion defines a main distribution section and a secondary stationary section, the diameter of the main distribution section being smaller than the diameter of the upper section, the lower sealing lip always contacting the main distribution section during the stroke of (all) the plunger, while the upper sealing lip is axially located at the height of the secondary stationary section in the stationary position, and contacts the main distribution section at least at the end of the plunger's stroke, and preferably during most of the plunger's stroke, characterized in that: - The upper sealing lip contacts the secondary stationary section in the resting position, and - The plunger, in its resting position, makes sealing contact with the raceway only through its upper sealing lip.

[0005] Therefore, the lower lip, still in contact with the main section of the cylindrical portion, ensures a good seal, and the upper lip, freed from the strong radial stress with the cylindrical portion, can freely center itself on the raceway, is widened, and ensures a complete seal with both the raceway and the secondary stationary section. Due to reduced friction of the plunger within the cylindrical portion, the seal with the raceway is better, which increases the thrust of the return spring on the plunger, thus making the plunger press more forcefully against the raceway. Furthermore, the upper lip is protected, resulting in less stress against the cylinder in the stationary position, which still accounts for most of the pump's lifespan. Therefore, the advantages are multifaceted: relief of radial stress on the upper lip, centering on the raceway, allowing the upper lip to open, strengthening the seal on the raceway, and extending service life through contact with the cylindrical portion.

[0006] The fact that the collar only contacts the upper sealing lip means that the thrust applied by the return spring is concentrated and applied to make a sealing press contact between the upper sealing lip and the collar, which produces radial deformation (expansion) of the upper lip until the upper lip contacts the sub-stationary section in the rest position.

[0007] In practical implementations, the collar may define a truncated conical contact surface, and the upper sealing lip may be included at an upper end that internally defines a rounded contact surface, which in a rest position makes sealing press contact with the truncated conical contact surface. This sealing contact is advantageously the only sealing contact between the plunger and the collar.

[0008] In addition, the upper sealing lip may include an upper end portion that defines a sealing sliding edge on the outside, which makes sealing contact with the main distribution section of the cylindrical portion.

[0009] According to one aspect of the invention, the main distributing section may be cylindrical, and the secondary stationary section may be truncated conical. In a variation, the main distributing section and the secondary stationary section may be cylindrical and connected by a truncated conical connecting section.

[0010] Typically, as fluid is removed from the bottle, it is necessary to introduce outside air into the bottle. This outside air passes through a venting channel along the collar. According to the invention, this venting channel can be closed in the resting position by a sealing contact between the upper sealing lip and the collar. Therefore, any fluid leakage through this venting channel is impossible.

[0011] The spirit of this invention lies in reducing the radial stress on the upper sealing lip to improve its centering, and increasing the axial support of the abutment ring to open the upper sealing lip, thereby establishing contact with the substationary section in the rest position. Attached Figure Description

[0012] The invention will now be described more fully with reference to the accompanying drawings, which illustrate three embodiments of the invention by way of non-limiting example.

[0013] In the attached diagram:

[0014] Figure 1 This is a vertical cross-sectional view through the pump of the present invention, which is in a stationary position;

[0015] Figure 2 It shows Figure 1 A greatly magnified view of the pump's details.

[0016] Figure 3 At the start of actuation Figure 2 Similar views, and

[0017] Figure 4 During the actuation period and Figure 2 and Figure 3 A similar view. Detailed Implementation

[0018] First refer to Figure 1 The overall structure of the pump will be described. The pump includes a pump body 1, an actuator rod 2, a plunger 3, a collar 4, a return spring 5, and a ball 6 forming a movable inlet valve component.

[0019] The pump body 1 is generally cylindrical and rotatable. The pump body 1 internally defines a sliding cylindrical portion 11 for the plunger 3. An inlet sleeve 12 for receiving an immersion tube is formed at the bottom end of the pump body 1. An inlet valve seat 13 is located in the extension of the inlet sleeve 12, on which a ball 6 rests. The seat 13 and the ball 6 together form the pump's inlet valve. Other shapes for the movable valve member can be imagined instead of the ball 6. A protruding collar 14 with external grooves is formed at the upper end of the pump body.

[0020] The actuating rod 2 is axially movable back and forth within the body 1. The rod 2 is assembled from two parts: an upper part 20 and a lower part 25. The upper part 20 includes a rod tip 21 for receiving a pusher, which the user presses to move the actuating rod 2. Below this rod, the rod 2 forms an outer skirt 22 and an inner bushing 24. The upper part 20 has a conduit 23 axially passing through it. The lower part 25 forms a pin 26 fixedly engaged in the inner bushing 24 and a seat 27 for the pump's outlet valve.

[0021] The plunger 3 includes a lower sealing lip 31 and an upper sealing lip 32 located on the outer side of the plunger. The two lips 31 and 32 are oriented in opposite directions but have the same outer diameter. The plunger 3 also has an inner lip 34 with a smaller diameter. The plunger 3 also has a valve lip 33 that extends concentrically inside the lower sealing lip 31.

[0022] The lower sealing lip 31 and the upper sealing lip 32 are in sealing sliding contact with the sliding cylindrical portion 11. The inner lip 34 is in sealing sliding contact with the outer skirt portion 22. The valve lip 33 is in selective sealing contact with the seat 27 to collectively form the pump's outlet valve.

[0023] Therefore, a pump chamber C is formed in the pump body 1 between the inlet valves 13, 6 and the outlet valves 27, 33. A plunger 3 is mounted on the actuating rod 2 so as to be movable between the seat 27 and the lower edge of the outer skirt 22, wherein the inner lip 34 slides within the outer skirt 22. When the valves open under the pressure present in the pump chamber C, the pump chamber C communicates with the pipe 23, forcing fluid from the pump chamber C through the pipe 23 to the actuator.

[0024] The collar 4 is fixedly installed in the pump body 1, and more precisely, it is installed around the upper portion of the protruding collar 14 forming the pump body 1. The collar 4 includes an inner abutting section 41 and an outer snap-fit ​​section 42, which snaps into the collar 14. The collar 4, as a thrust ring, may also be limited to the inner thrust section 41.

[0025] The return spring 5 rests on the retainer 7 and is located below the actuator rod 2, the retainer 7 restricting the freedom of the ball 6. The spring 5 pushes the actuator rod 2 upward, thereby driving the plunger 3 through the actuator rod 2. The plunger 3 is pushed against the collar 4, and more precisely, against the inner abutment section 41 of the collar 4. Axial contact between the rod 2 and the plunger 3 occurs at the outlet valves 27 and 33, and axial contact between the plunger 3 and the collar occurs at the upper sealing lip 32. The collar 4 thus defines the resting position of the plunger, the actuator rod 2, and the entire pump.

[0026] When the user presses the pusher (not shown) mounted on the tip 21 of the actuator 2, the actuator rod descends and sinks into the pump body 1. The upper sealing lip 32 disengages from the collar 4, and the valve lip 33 also disengages from its seat 27. The pump chamber C opens toward the pipe 23, and the plunger 3 completes its full stroke in the sliding cylindrical section 11. The ball 6 is pressed against its seat 13. When the user releases the pressure on the pusher H, the actuator rod S returns to its rest position under the action of the return spring. The outlet valve closes and the inlet valve opens to draw another dose of fluid product into the pump chamber C. External air can enter the fluid product reservoir through the vent passage 4e formed around the inner abutment section of the collar 4.

[0027] This is a very classic design and operation of a manual pump.

[0028] According to the invention, the sliding cylindrical portion 11 is not completely cylindrical over its entire height, but has a portion with an increased diameter at its upper end. More specifically, in the embodiment shown in the drawings, the sliding cylindrical portion 11 defines a main distribution section 111 and a secondary stationary section 112 at its upper end, the main distribution section extending over most of the height of the cylindrical portion, and the secondary stationary section extending over a smaller portion of the height of the cylindrical portion. In a variation not shown, the main distribution section 111 may be reduced in height, while the secondary stationary section 112 may be further extended. As an example, the secondary stationary section 112 may have the same height as the main distribution section 111, or even a greater height.

[0029] The diameter of the main distribution section 111 is smaller than the diameter of the secondary stationary section 112. The increase in diameter of the secondary stationary section 112 relative to the main distribution section 111 is approximately a few percent or even a few tenths of a millimeter. The main distribution section 111 is cylindrical over its entire height, while the secondary stationary section may be truncated conical. Preferably, as shown in the figure, the secondary stationary section 112 is cylindrical and is connected to the main distribution section 111 via a truncated conical connecting section 113.

[0030] When plunger 3 is in the stationary position, such as Figure 2 As can be seen, the upper sealing lip 32 is pressed against the collar 4, which deforms the upper sealing lip 32, thereby bringing it into contact with the secondary stationary section 112. The collar 4 opens the upper sealing lip 32, increasing its diameter until it contacts the secondary stationary section 112. When the plunger 3 moves downward, the upper sealing lip 32 disengages from its pressing contact with the collar 4 and returns to its stress-free shape, i.e., with a reduced stationary diameter. Therefore, the upper sealing lip 32 also disengages from its contact with the secondary stationary section 112. Then, the upper sealing lip 32 engages with the truncated conical connecting section 113, as shown... Figure 3 This can be seen from the image. It can be noted that the upper sealing lip 32 does not contact the truncated conical connecting section 113. By continuing the stroke of the plunger 3, as... Figure 4 As can be seen, the upper sealing lip 32 contacts the main distribution section 111, during which the plunger 3 will travel most of its stroke. Furthermore, even with the lower height of the main distribution section 111 as described above, the upper sealing lip 32 will always contact the main distribution section 111 at least at the end of the plunger's stroke.

[0031] More specifically, the bottom end of the outer skirt 41 of the collar 4 defines a downwardly and outwardly facing truncated conical contact surface 412. Additionally, the upper sealing lip 32 includes an upper end portion internally defining a rounded contact surface 322, which abuts against the truncated conical contact surface 412 in a sealed contact position. Therefore, the rounded contact surface 322 can slide and open on the truncated conical contact surface 412 until it contacts the secondary stationary segment 112. Thus, the upper sealing lip 32 is constrained in a stationary position to establish a double seal, which is highly advantageous.

[0032] Without departing from the scope of the invention, in an inverted manner, the collar 4 may define a rounded contact surface, while the upper sealing lip 32 may define a truncated conical contact surface. In all cases, either a rounded contact against a truncated conical contact or a truncated conical contact against a rounded contact is advantageous, as this allows relative sliding until the final position of maximum sealing is reached.

[0033] Advantageously, the upper end of the upper sealing lip 32 is externally defined with a sealing sliding edge 321, which contacts the secondary stationary section 112.

[0034] It should be noted that in the rest position, the plunger 3 only seals against the collar 4 through its upper sealing lip 32. In other words, the rounded contact surface 322 is the only contact area between the plunger 3 and the collar 4. Furthermore, the taper of the truncated conical contact surface 412 and the rounding of the rounded contact surface 322 ensure the centering of the plunger 3 relative to the collar 4. Additionally, axial contact increases due to the reduction or elimination of radial stress. It can be observed that the vent passage 4e is closed in the rest position through the sealing contact between the upper sealing lip 32 and the collar 4. Therefore, the pump seal is fully ensured on one hand by the lower sealing lip 31 and on the other hand by the upper sealing lip 32, with the lower sealing lip 31 permanently maintaining a sealing sliding contact with the main distribution section 111 of the cylindrical portion 11, and the upper sealing lip 32 forming a reinforced sealing contact with the collar 4.

[0035] Therefore, the present invention provides a pump in which the seal is strengthened in the static position.

Claims

1. A pump for dispensing fluid products, the pump comprising: - Pump body (1), wherein the pump body (1) has a sliding cylindrical portion (11) defined inside. - Actuating rod (2), which is capable of moving axially back and forth within the body (1); as well as - A plunger (3) is mounted on the actuating rod (2) and slides in a sealed manner in the sliding cylindrical portion (11) during the stroke of the plunger. The plunger (3) is formed with a lower sealing lip (31) and an upper sealing lip (32). - A collar (4), which is fixedly installed in the pump body (1), - A return spring (5) forces the plunger (3) against the collar (4) in the stationary position of the pump. The sliding cylindrical portion (11) defines a main distribution section (111) and a secondary stationary section (112). The diameter of the main distribution section (111) is smaller than the diameter of the secondary stationary section (112). The lower sealing lip (31) is always in contact with the main distribution section (111) during the stroke of the plunger, while the upper sealing lip (32) is axially located at the height of the secondary stationary section (112) in the stationary position and is in contact with the main distribution section (111) at least at the end of the plunger's stroke. Its features are: - The upper sealing lip (32) contacts the secondary stationary section (112) in the stationary position, and - The plunger (3) in the rest position makes sealing contact with the collar (4) only through the upper sealing lip (32) of the plunger (3).

2. The pump according to claim 1, wherein, The collar (4) defines a truncated conical contact surface (412), and the upper sealing lip (32) includes an upper end portion that internally defines an inverted rounded contact surface (322), which slides and abuts against the truncated conical contact surface (412) in the rest position to seal the press contact.

3. The pump according to claim 1 or 2, wherein, The upper sealing lip (32) deforms outward through the collar so as to open in the rest position and contact the secondary rest section (112).

4. The pump according to claim 1, 2 or 3, wherein, The upper sealing lip (32) includes an upper end portion that is externally defined by a sealing sliding edge (321), which is in sealing contact with the main distribution section (111).

5. The pump according to any one of the preceding claims, wherein, The main distribution section (111) is cylindrical, and the secondary stationary section is truncated conical.

6. The pump according to any one of the preceding claims, wherein, The main distribution section (111) and the secondary stationary section (112) are cylindrical and are connected by a truncated conical connecting section (113).

7. The pump according to any one of the preceding claims, wherein a vent passage (4e) is defined, the vent passage (4e) being closed in the rest position by a sealing contact between the upper sealing lip (32) and the collar (4).

Images