FR2560160A1 - Piston pump for sprayer - Google Patents

Abstract

In order to improve the fluidtightness in the rest state of a sprayer pump, the piston 2 comprises a second sealing lip 22 which, in the rest state, becomes jammed between the internal wall 11a of the pump body and the lower edge 62 of a ferrule placed between the pump body and the rod 3 of the piston. The rod 3 of the piston is widened at its lower part and has a conical surface 31 which becomes engaged in the bottom of the ferrule 6, and spreads it elastically, thus providing excellent fluidtightness

Description

The second part of this report is a further development of

  valves for aerosol can of the type Odpe Qe; to vaporize the contents * l bi * 'rz, fo-n-gant- a piston recalled in repo position by so-k D: n men ?, ae these devices comprise a body dq p ampe sat' n ' In the past, the outer end of the dhaapeo is positioned in a groove. capsule with i.nterposition 1- funL round-it of joint ddt 1 Uo-rverture

  central unit passes through a solid core of: a piston

  smoothing out of the pump body.

  5 An eS-oig spring in the chamere and recalls the piston towards the iau-au Auf rest, the upper part of the piston, these e; ' adire L face opposite the clapper is applied by the re-ssort contlre the r welle of join and it is what

  ass-ure 'tanche-6hté ólu can when you do not use it.

  The heads of stumps may also include other provisions depending on the characteristics and

pump applications.

  Such a pmp is intended to be jetted with the can when it is empty. She is part of! "lost" packaging. Its cost price must therefore remain low. However, the pump must meet certain conditions.

  quality. Among other things, there must be no leaks.

  Seals should not be contacted with the liquid to be sprayed as some liquids may attack the seals. This results in liquid pollution and leakage. For these reasons, these pumps are the subject of studies to improve the qualities without unreasonably raising the cost price and, if possible to reduce it,

  which is contradictory and therefore difficult.

- 2 -

  The present invention relates to a vaporizing pump

  having an improved water-resistance in the state of

  rest, and a lower cost price.

  This result is obtained, according to the present invention, which proposes a vaporizer pump for mounting in the neck of a container such as a bicon, comprising a body

  pump internally defining a chamber of compres-

  cylindrical section with an inner end inserted into the neck of the can, riunie a valve and an outer end open, emerging outside the can, a piston provided for sliding in the cyiindrique chamber,

  with a sealing lip pointing towards the end

  and a piston rod extending through the open outer end of the pump horn and a spring disposed in the chamber between the piston and the inner end of said chamber. This pump is

  remarkable by the following two characteristics:

  in combination: 1) the piston rod has in the vicinity of the piston a conical portion thicker; and 2) the pump further comprises a tubular element with

  an outer end and an inner end,

  placed between the piston rod and the pump body, said tubular element being secured to the pump body in the vicinity of the respective outer ends of this element and the pump body, so that when the piston with the rod rises towards the outside end of the pump body, under the action of the return spring, the conical portion of the rod engages inside the tubular element, and comes into contact with the inner edge of the lower part of the tubular element and ensures a sealing contact with elastic separation of the lower part of said tubular element. This gives an excellent seal between the conical portion of the piston rod and

the tubular element.

  According to another characteristic of the invention, the piston comprises a second sealing lip oriented towards the outer end of the chamber, of dimension

  provided that in the rest position of the piston, under the ef-

  spring of the return spring, said second lip is engaged between the lower end of the tubular element and the

wall of the pump body.

  The lower end of the tubular element, separated by the conical portion of the piston rod, is applied

  against the piston, thus forming an additional seal.

  The second lip of the piston is itself applied against the inner wall of the pump body. This gives a perfect seal, without having a seal material

elastomer.

  Other features of the invention will appear in

  course of the description which follows, given as

  non-limiting example, with reference to the attached drawing, 2e and which will understand how the invention can be achieved. The single figure of the attached drawing shows on the left half a half-section of an embodiment of the invention, with the piston down and on the right half, a half-section of another embodiment with the piston

in the rest position.

  In both embodiments of the invention, the pump comprises a pump body 1 defining a compression chamber 11, with a not shown inner end and an open end 12, and a piston 2, with a hollow rod. 3 defining an axial ejection channel 4, and a return spring 5 urging the piston

  to the top. The pump has other elements not shown

  such as valves, if necessary precompression members, etc., which are not concerned by the present invention. The return spring is shown to bear directly on the piston, but of course there may be other elements interposed between the piston

2 and the spring 5.

  The piston 2 comprises a first sealing lip 21 facing downwards, that is towards the bottom or towards

  the inner end of the compression chamber 11.

  When the piston goes down and a pressure is established in the chamber 11, this pressure applies the lip 21 against the inner wall 11a of the chamber, which thus ensures

sealing in a known manner.

  it is a characteristic of the invention, the lower part of

  3'l of the ': ie 3, in the vicinity of the piston, from

  a: Pt, here a conicque form determining an overpayment

  = - -, e o -, po..np-.r-te a tubular element such that a-e-p. ace. eSxtremity open pump body,

  e p - ompQ and the rod 3 of the piston. This video

  c::. 6 is on the same length, and has a

  G. 6 and an inner end 62.

  LJ ....... <....-; i .: E.e 6 'is made aware of

  2. The pump body by any suitable means is also provided with a ferrule 12 and 62 of the ferrule is 1t: r of ferrule 6_ at least next =

  1 - Jorn, in the middle of the 6th, is superior to the dia-

  The stem 3 at point P, but less than the diameter 10o plus / Sg. i.

  31. As well as the piston 2 and the ge 3 go up under the return spring 5 'L3 surdace, internal n-Zrieure 652b e ferrule 6 comes -.pp.-luer on the U arti '. taper 31 of the rod 3 and, under DTD: the wedge effect, due to the force of the spring 5, deviates radially

  In this case, with the shaft 3, the seal is excellent, and the piston has a second lip. 22 This second lip 22 may be identical or not to the first one, along the inner wall 11a towards the open outer end of the pump body 11. In the drawing, it is shown a little thinner and faster The distance d between the edge 62a of the end 62 is chosen slightly greater than the thickness of the edge of the lip 22, so that when the piston 2 goes back under the effect of the spring 5, the lip 22 comes to engage between the inner edge 62 of the ferrule and the inner wall 11a of the compression chamber, as shown on the right half of the figure. Advantageously, the lower end 62 of the shell has a section for example bevel, so as to be slightly spaced from the inner wall 11a of the compression chamber at this level. Instead of a bevel, 6 - one could provide a shoulder, a curve, etc. This produces a double seal. on the one hand between the conical portion 31 of the rod 3 and the outer part 62 of the ferrule and, on the other hand between the lip 22 and the edge 62 of the shell 6. When the device is in the state of rest , the spring 5 permanently maintain these contact surfaces against each other, and etanne5Ehê is ensured in a safe manner, without the use of jeopardically or mechanically fragile joints. This arrangement is opposed to the fluaze of the piston in the direction of loosening. The lip 22 of the piston is also elastically applied against the internal caroli 11a of the pump body, by the wedge effect of the conical surface 31,

  biased upwards by the spring 5.

  A first example of fixing the ferrule on the body

  pump is shown on the left half of the figure.

  The outer end 61 of the ferrule is formed with a circular flange 6! A which is placed on the outer end 12 of the pump body, which has an extra thickness 12a and a capsule 7 crimps the extra thickness 12a and the flange 61a with a seal 8. The capsule is also set on the neck of a can not shown on this

half of the figure.

  A second example of fixing the ferrule on the pump body is shown on the right half of the figure. The ferrule 6 is secured to a tube 9 placed outside the

  pump body 1, the tube and the ferrule being connected together

  by a portion 10 forming a circular channel 10a returned The tube 9 is formed with a circular protuberance 9a which engages under the extra thickness 12a of the pump body, so as to wedge the ferrule on the pump body, without any

other means such as a seal.

  For assembly, the piece (turret) formed by the ferrule 6, the tube 9 and the circular channel 10a is engaged on the open outer end 12 of the pump body, and the latching is obtained by a suitable pressure. The attachment of the pump to the can can be obtained simply ern providing a circular collar 91 external, at the bottom end of the tube 9, and this collar is crimped, with interposition of a seal 92, on the neck 93 of a can by means of a crimping flange-94. It can be seen that in this case, it suffices for a single washer 92 providing a static seal to mount the pump on the can. The device is safe, simple and economical. In addition to the seal at rest, the second lip 22 improves the quality of the suction during the ascent movement

of the piston.

  There is shown in 65 a passage groove for the equilibrium of the gas pressures. There may be one or more, distributed circumferentially, both in this embodiment and in that of the right half of the

Fig.

  If a seal 8 has been shown on the left part of the figure with a suitable shape of the upper part 61 of the shell 6, it is understood that one could provide another section of the ferrule for

to dispense with such a seal 8.

  It goes without saying that the described embodiments are only examples and that it would be possible to modify them, in particular by substitution of technical equivalents, without

  to get out of the scope of the invention.

Claims (6)

claims   1. Spray pump for mounting in the neck of a container such as a can, having a pump body (1)   internally defining a compression chamber cy-   lindrique (11) with an inner end inserted into the neck of the can, provided with a valve and an outer end   (12) open, emerging outside the can, a pis-   a tone (2) for sliding in the cylindrical chamber, with a sealing lip (21) facing the end; interior of the chamber and, with a piston rod (3) exiting through the open outer end of the pump body and a spring (5) disposed in the chamber between the piston and the inner end of said chamber, characterized in that that: 1) the piston rod (3) has in the vicinity of the piston (2) a conical portion (31) thicker; and, 2) the pump further comprises a tubular member (6) with an outer end (61) and an inner end (62) disposed between the piston rod and the pump body, said tubular member being secured to the body in the vicinity of the respective outer ends (12, 61) of this element and the pump body so that when the piston (2) with the rod (3) rises towards the outer end of the pump body, under the action of the return spring (5), the conical portion (31) of the rod (3) engages inside the tubular element (6), and comes into contact with the inner edge (62b) of the lower part of the tubular element (6), and ensures a sealing contact with elastic separation of the lower part (62b) of said tubular element (6). 2. Pump according to claim 1, characterized in that the piston (2) comprises a second sealing lip (22) orienti towards the outer end of the chamber, of dimension designed so that in the rest position of the piston ( 2), under the effect of the return spring (5), said second lip (22) is engaged 9 - between the lower end (62) of the tubular element (6) and the wall of the pump body (1 ) o 3. Pump according to claim 2, characterized in that the inner end (62) of the tubular element (6) is   formed with a beveled outer profile.   Pump according to one of claims 1 to 3, characterized   the tubular element (6) comprises, in the vicinity of its outer end (61), an external flange (61a), to allow its fixing by crimping on the end (12) of the pump body (1j   5. Pump according to one of claims 1 to 3, characterized   in that the tubular element X6) is connected to its end.   an outer tube (10) with an outer tube (9) in such a way that the outer end (12) of the pump body can be accommodated between the tubular element (6) and the outer tube (9), in the circular channel (10a).   6. Pump according to claim 5, characterized in that the outer tube (9) comprises an outer collar (91) to allow its attachment by crimping the neck of a can (93).