Patent Publication Number: US-9884335-B2

Title: Hand held dispenser

Description:
The present invention refers to a manually operated pump for dispensing fluid substances, provided with a facilitated operation. 
     In particular, the present invention refers to a pump that can be associated with a container, in which the fluid substance to be dispensed is preserved. 
     Various types of manually operated pumps have been known for some time. 
     EP 0065 214 A2 describes a pump with particularly simple operation, obtained for being mounted very easily, with limited cost. 
     Such pump comprises a cup-shaped body that has, on its bottom, a hole and a boss connected to a drawing tube. The hole obtained on the bottom of the cup-shaped body is associated with a suction valve, which is obtained by a spherule housed in a suitable seat on said bottom. Such spherule is maintained in position by a system of flexible tabs for its insertion in the seat. 
     Within the cup-shaped body, a piston is situated that has a lip adapted to make a seal on the internal surface of the cup-shaped body. The piston has a step, against which a first end of a return spring is abutted. A second end of such spring is instead abutted against the bottom of the cup-shaped body in proximity to the suction valve. 
     An internally hollow stem extends from the piston, for actuating the pump. A second spherule is contained in the cavity of the stem, such spherule abutted against a suitable conical housing; such second spherule constitutes a delivery valve of the pump. Such second spherule is loaded by a main spring interposed between a perforated stop fit on the top of the stem and the spherule itself. 
     Positioned on the stem is a dispenser cap provided with a cavity for the outflow of the fluid and with a head adapted to be pressed in order to actuate the pump. 
     The cup-shaped body is suitably and sealingly associated with a ring nut dedicated to fixing the pump on a container that contains the fluid substance intended to be dispensed by the pump. 
     When the entire pump, suitably associated with a container and in use conditions, is placed in a reduced pressure environment, it has been shown that the delivery valve has some leaks, which are quite troubling. 
     In order to remedy such problem, it has been thought to increase the pressure generated by the spring on the sphere that forms the delivery valve. While this solved the problem of the leaks, it introduced a factor of considerable inconvenience for the user. 
     Indeed, by increasing the load of the delivery spring, the force necessary for the actuation of the pump (FTA—Force to actuate) is also considerably increased and in such conditions the dispenser button is too ‘hard’ to press for the dispensing. 
     Object of the present invention is to obtain a manually operated pump for dispensing fluid substances, which does not have leaks from the delivery valve and which at the same time results easy to actuate for a user (Low FTA). 
     These and other objects are achieved by obtaining a manually operated pump according to the technical teachings of the enclosed claims. 
     A further advantage of the present invention is to obtain a pump that can be easily and quickly assembled, without having to possess overly sophisticated mounted equipment. 
     Not least object of the present invention is to provide a pump that is reliable and durable in use as well as inexpensive to produce. 
    
    
     
       Further characteristics and advantages of the invention will be evident from the description of a preferred but not exclusive embodiment of the manually operated pump, illustrated as a non-limiting example in the enclosed drawings, in which: 
         FIG. 1  is an axial section view of the pump of the present innovation, when in a rest position (or upper end of travel); 
         FIG. 2  is a section view of the pump of  FIG. 1 , when it is in a lower end of travel position; 
         FIG. 3  is a cross section view, taken along the line  3 - 3  of  FIG. 1 ; 
         FIG. 4  is a section view of a detail of the pump of  FIGS. 1 and 2 ; 
         FIG. 5  shows a graph of the force to actuate a pump similar to that of  FIG. 1  but when the opening of the conical surface is equal to 15°; 
         FIG. 6  shows a graph of the force to actuate a pump similar to that of  FIG. 1  when the opening of the conical surface is equal to 17°; 
         FIG. 7  shows a graph of the force to actuate the pump of  FIG. 1 , provided with an opening of the conical surface equal to 20°; 
         FIG. 8  shows a graph of the force to actuate a pump similar to that of  FIG. 1  when the opening of the conical surface is equal to 22°; and 
         FIG. 9  shows a graph of the force to actuate a pump similar to that of  FIG. 1  when the opening of the conical surface is equal to 25°; 
         FIG. 10  shows a graph of the force to actuate the pump of  FIG. 1 , after the first actuation which is illustrated in the graph of  FIG. 7 . 
     
    
    
     With reference to the abovementioned figures, a manually operated pump is shown, indicated overall with the reference number  1 . 
     As can be immediately observed from the figures, the pump in question has a very simple structure, and is formed by a very limited number of suitably molded pieces. It can thus be easily assembled. 
     The manually operated pump  1  is intended to dispense a fluid substance contained inside a container  6  (only partially shown), to which said pump can be associated by means of a suitable bottom  2  (or ring nut), which will be described hereinbelow. 
     The pump comprises a cup-shaped body  3  provided on its bottom  3 A with an opening  4  associable in a known manner with a drawing tube  5  inside said container  6 . 
     From the bottom of the cup-shaped body, an internally hollow cylindrical element  7  departs in the direction opposite the tube; such cylindrical element  7  has at its top a first seat  9  shaped substantially frustoconically (converging towards the opening  4 , and hence towards the bottom of the cup-shaped body), in which a spherule  8  is housed. The first spherule  8  and its first seat  9  form a suction valve of the pump  1 . 
     Inside the cup-shaped body  3 , a sealing piston  11  is slidable (on the internal surface  3 B of the cup-shaped body), in opposition to a return spring  10  only partially shown and interposed between the piston and the bottom of the cup-shaped body. From the piston  11 , a hollow stem  12  is extended, one end  12 B thereof projecting towards the exterior of the cup-shaped body, through the ring nut or bottom  2 . 
     In the present embodiment, the stem and the piston are obtained in a single piece, via molding of plastic material, preferably made of PE. The piston is advantageously provided with a single sealing lip. 
     The cavity of the stem is connected with a compression chamber  15  of the pump which is defined by the part of the piston  11  directed towards the bottom of the cup-shaped body  3 , and by the cup-shaped body  3  itself. 
     The hollow stem  12 , at a portion  13  thereof of connection with the piston  11 , has a second seat  14  obtained by a wall  140  defining on the lower part an opening  20 . Such wall  140  is projecting towards the compression chamber  15  and defines a substantially frustoconical surface  14 A, converging towards said compression chamber, against which a movable element  16  is abutted. Preferably the frustoconical surface has an opening comprised between 17° and 22°, preferably 20°. 
     The second seat  14  and the movable element  16 , sealingly cooperating, act as a delivery valve of the pump. 
     It should be noted that the movable element  16  is loaded by a spring  18  placed in the cavity of the stem  12  and which has a first end abutted thereon, and another end abutted against a surface suitably provided on a dispenser button  19  fit on the end  12 B of the stem  12 . The dispenser button preferably has an insert  21  that acts as a spray nozzle. 
     The movable element  16  is better illustrated in  FIG. 4 , where all of its particular features can be appreciated. It is preferably obtained via molding of plastic material (e.g. polyethylene resin sold by DOW Chemicals with the commercial name DOWLEX 2552E, or with a plastic material with a Shore D hardness comprised between 46 and 50, preferably 48, measured according to ASTM D2240) in a single piece. As can be observed, the element  16  has an external surface substantially formed by two frustoconical parts  16 A joined at a transverse plane of symmetry X of the element. The symmetry is not perfect, given that—as can be seen from the section—the element  16  has a central lightening  16 C actually constituted by a blind hole obtained via molding. 
     The hole is particularly useful for preventing risks of suction during the steps of molding the movable element. 
     The frustoconical parts at the ends of the movable element  16  are tapered and have a step  16 B of passage between the tapered portion and the frustoconical part. 
     The step is quite useful since—when the movable element is raised even only slightly during dispensing—the dispensing opening results quite wide and allows a considerable flow of product to be dispensed. 
     The angle γ or opening (represented in the figure) which defines the conical surfaces, for the purposes of the invention is comprised between 17° and 22°, preferably 20° (deg). It has in fact been verified that this interval of opening angles results optimal for the operation of the pump, as will be described hereinbelow with the aid of the graphs of  FIG. 5-9 . 
     It should be observed that for such opening angles, the presence of the step  16 B is extremely important. Indeed, without the step, the smaller the opening angle of the ‘cone’, the smaller the opening for the fluid given the same ‘lift’ of the movable element. The presence of the abovementioned step provides a passage opening (between the seat of the delivery valve and the movable element) which is wide even in the case of opening angles of the conical surfaces that are rather small, like those described. 
     The ‘functional symmetry’ of the element  16  is very important for the mounting. Indeed, it does not require being oriented when it is positioned in the seat  14  before the delivery spring  18 , nor does it matter if it falls in the stem  12  with the opening of the lightening hole upward or downward. With the term ‘functional symmetry’ in the present text, it is intended the symmetry of those conical surfaces intended to make the seal in the seat. 
     The dispenser button  19  has a normal sealing coupling by interference, preferably with the external surface of the stem  12 . It is also provided with a spray nozzle. 
     As can be seen from the drawings, a gasket  22  is fixed on the external surface of the stem  12 , at the piston  11 . Such gasket is positioned on an enlargement or annular groove  23  suitable obtained on the surface of the stem. 
     Such gasket  22 —which according to its height also allows an adjustment of the piston travel, and thus of the volume of the compression chamber—when the pump is in a rest position (represented in  FIG. 1 ) is in abutment against the bottom  2  (or ring nut). The bottom has a hole  2 A through which the stem  12  passes and a neck  2 B seamed in  2 C to an annular abutment  26  obtained at a free end of said cup-shaped body  3 . 
     It should be noted that the annular abutment  26  has a notch  26 A adapted to allow the passage of the air from the outside to the inside of the container (venting), at least when said gasket is detached from said bottom (i.e. during the travel of the piston). 
     Advantageously the bottom or ring nut  2  is simply formed by a thin plate of metal material, preferably aluminum, suitably shaped and folded during mounting in order to lock the pump  1  to the container  6 . 
     As can be seen in  FIG. 1 , the ring nut or bottom (which in such representation is not yet locked to the container  6 ) has a cylindrical portion that surrounds the neck  6 A of the container and which once suitably deformed, engages as an undercut on the neck of the bottle. 
     Between the container  6  and the ring nut  2  or bottom, a conventional sealing gasket  27  is suitably inserted. 
     As can be clearly seen in  FIG. 1 , which represents the pump in rest position, the second seat  14  and the movable element  16  are configured in a manner such that, when the element  16  is in closure position, it partially projects from the second seat  14  itself towards the bottom of the cup-shaped body (inside the compression chamber). Advantageously, in the represented embodiment, it is the tapered end portion of the movable element that projects from the seat  14 . 
     When the piston is at the end of travel (see  FIG. 2 ), the movable element  16  (and specifically a portion thereof projecting from the second seat  14 , which substantially corresponds with the tapered portion) comes into contact with the spherule and is lifted in opposition to the main spring  18 . In this manner, the opening of the delivery valve is caused. 
     This allows the outlet, towards the nozzle, of the compressed air present in the compression chamber with the initial actuations of the pump, thus allowing a facilitated priming of the pump itself. 
     It should be observed that in this embodiment, the end stop of the piston is determined by the contact between the button and the bottom—while the cylindrical element  7  in which the seat of the suction valve is obtained, and the wall  140  that defines the seat of the delivery valve, given that they are rather delicate elements, never come into contact with each other. 
     This characteristic is extremely important since the end stop of the piston is achieved between two structurally rigid elements, and hence the lip  11 A of the piston—an extremely delicate part—never comes into contact with the bottom surface of the cup-shaped body (i.e. of the step  3 D), thus preventing deformations. 
     Preferably, in such embodiment, the first seat  9  is in a raised position with respect to the bottom of the cup-shaped body and projecting towards the delivery valve  14 / 16 . The seat  14  of the delivery valve is instead in a more raised position with respect to the sealing lip  11 A of the piston. 
     From that described above, the operation of the invention appears evident for the man skilled in the art and there is no need to discuss it further since the pump is represented in  FIG. 1  in a rest position and in  FIG. 2  in an end of travel position. 
     It should only be observed that during the travel of the piston, the gasket  22  is detached from the ring nut or bottom, thus allowing the outside air to enter within the container (venting), first through an annular slit that is created between the bottom (or ring nut) and the stem, continuing through the notch  26 A obtained in the annular abutment of the cup-shaped body  3 . 
     In addition, the above-described pump is extremely inexpensive since it is obtained with a very limited number of suitably molded pieces. The suitably molded pieces (cup, stem/piston and movable element  16 ) are all easily obtained via molding of plastic material, while all the other components are standard and commonly used on pumps. They are thus normally present on the market and easy to find. 
     Furthermore, the assembly of the pump results extremely simple, as is inferred from the mounting procedure described hereinbelow. 
     First of all, arranged on the work holders are the gasket  27  and subsequently the cup-shaped body  3 , which when inserted in the gasket slightly deforms it in a manner such that the same remains constrained thereto. 
     The sphere is then positioned in the first seat  9 , and subsequently the return spring  10  is positioned inside the cup-shaped body. It should be observed that the spring, simply cast in the cup-shaped body, is automatically positioned around the boss  7  that projects from the bottom of the cup-shaped body  3 . 
     Then, the piston/stem is inserted in the cup-shaped body and the gasket  22  is fit on the stem. 
     At this point, the movable element  16  is placed in the stem. It is automatically oriented and by virtue of its “functional symmetry” it does not matter if the opening of the lightening hole is directed upward or downward. In addition, the keg-shaped form, with the conical surfaces, renders the correct positioning in the seat  14  practically automatic. The main spring  18  is subsequently inserted. The gasket is positioned and the bottom  2  is fit on the cup-shaped body, and the seam  2   c  is executed. 
     Finally, the dispenser button  19  is fit on the stem, and the drawing tube  5  is inserted in the suitable seat. 
     As can be seen from the above-described operations, the mounting of the described pump is extremely simple. The considerable advantage obtained by the use of a spherule and an automatically orientable movable element, in place of other valve means, lies in the obtainment of an even quicker mounting, which decreases the cost of the pump. 
     Finally, it should be noted that such pump is extremely reliable. 
     The particular trigger mechanism which provides for the contact between the movable element  16  and the sphere of the suction valve is very effective and quite reliable. 
     In addition, the expulsion of air and a negligible amount of product at the end of travel occurs in the natural direction of dispensing of the substance contained in the container, thus preventing the onset of any type of problem. 
     Furthermore, as can be observed in the drawings, the return spring results perfectly centered on the lower part by the boss  7  and on the upper part by the projecting portion inside the chamber  15  of the seat  14  of the delivery valve. This ensures that, during the use of the pump, the spring always remains perfectly centered and in position, increasing the overall reliability of the pump. 
     It should also be observed that in the present pump, the spherule of the suction valve in its operating movement is confined laterally by the return spring, on the upper part by the lower portion of the seat of the delivery valve, and on the lower part by the seat of the suction valve. Other projections, bosses, tabs and the like would therefore not be necessary in order to maintain the sphere in position, with savings on the molding costs of the cup-shaped body. Advantageously, however, for safety purposes, small projections  9 A are still obtained in the seat  9  of the suction valve. Such projections are deformed upon the insertion of the sphere in its seat, and here they confine the sphere during the suction action, hence allowing the passage of the product flow that fills the compression chamber. 
     With reference to the particular configuration of the movable element  16  of the delivery valve, it should be noted that the opening angle γ of the conical surface (which is actually the angle formed by the intersection of two lines A and B parallel to or abutted against the external surface of the valve element  16 , belong to and intersect on a plain that contains the axis C of the valve element) allows the valve element  16  to ‘be fit’ in its seat  14 , which preferably has a form similar (corresponding) to the conical form of the element  16 . 
     The conical joint, which is achieved as the main spring  18  presses against the element  16 , also as a function of time, provides a perfect seal of the valve that it does not lose even when facing severe reduced pressure tests. 
     In addition, the presence of the blind hole in the movable element facilitates a very slight deformation of the conical walls of the movable element itself, when it is inserted in the seat, improving even more the ‘joining’ capacity. 
     Given the presence of the joint made between two conical surfaces, unlike that which occurs for conventional ball valves, it is not necessary to equip the pump with a spring with very high elastic constant; this fully benefits the ‘ease’ of actuating the button, which is clear after having overcome a first force peak necessary for decoupling the joint. 
     As can be seen in the graph  10 , which shows the force to actuate for the subsequent dispensing, such peak is much lower, once the pump has been actuated for the first time. 
     The advantage that is obtained in the use of the conical coupling between the valve element  16  and the seat  14  is clear from the analysis of the graph present in  FIG. 7 , referred to an opening of the cone of 20°. 
     As is seen during the first dispensing of the pump (after the same has been left to rest for a period of time), it is necessary to exert a force with a peak of about 2.5 kgf, but which then quickly descends to a value that remains around 1.5 kgf (an entirely acceptable value that provides an easy-to-move sensation). 
     In order to verify the optimal opening of the conical surface, many tests were performed that showed that an opening of the conical surface of the movable element  16  which is comprised between 17° ( FIG. 6 ) and 22° ( FIG. 8 ) is the best, with an optimal value of 20° ( FIG. 7 ). Indeed, it is seen that within these intervals, the peak value determined by the fitting of the movable element in the seat is around 2.5 kgf, which is an acceptable value (the force decreases with the increase of the opening angle). 
     It is instead seen that for greater opening values (such as 25° of  FIG. 9 ), the fitting effect is not very accentuated and practically useless, while for overly-low opening values (such as the 15° of  FIG. 5 ) the movable element is fit too well, requiring a force greater than 3 kgf for the initial actuation (which is not tolerable). 
     It has thus been verified that a coupling obtained with a movable element provided with a conical surface with opening ranging from 22° to 17°, with an optimal opening at 20°, provides an optimal compromise between vacuum sealing and ease of actuation of the pump. 
     Of course, in the above-described embodiments, also the seat in which the movable element makes a seal can be provided with a conical surface for the coupling with the surface of the movable element; in such case, the opening of such surface will be equal to that of the movable element or only slightly wider. 
     Various embodiments of the invention have been described, but other embodiments can be conceived by exploiting the same innovative concept.