HK1069790B - Trigger actuated pump sprayer - Google Patents

Description

Trigger actuated pump sprayer

Technical Field

The present invention relates to a trigger actuated pump sprayer.

Background

Trigger actuated pump sprayers are known for mounting to containers of chemical cleaners or the like for household use. Trigger actuated pump sprayers are typically grasped by an operator and actuated by pulling a trigger for reciprocally moving a pump piston to discharge a liquid product from a pump chamber through a discharge passage and a discharge orifice onto a target. The discharge orifice is typically formed in a nozzle cap that is mounted on the nozzle end of the discharge passage for rotation about a central axis of the nozzle cap. The nozzle cap may be snap-fit in place for manual rotation between open and closed positions in a non-axial movement manner, the nozzle cap including first and second pairs of flat outer surfaces that together define a nozzle cap body that is rectangular in cross-section. A rotating mechanism is designed in the pump body at the nozzle end, so that the discharge channel is in a closed position at two opposite rotating positions of the nozzle cover; and in the other two opposite rotational positions of the nozzle cap, the discharge passage is in one of the two open positions. The open positions are typically shown as "STREAM" and "SPRAY". Such a rotation mechanism is disclosed in U.S. Pat. No.4,706,888, which is incorporated herein by reference, which cooperates with a nozzle cap as previously described.

The flat outer surfaces of the walls of the nozzle cap are typically provided with indicia such as "OFF" on a first pair of opposing walls and indicia such as "STREAM" and "SPRAY" on a second pair of opposing walls for marking two OFF rotational positions and two on rotational positions of the nozzle cap. Such indicia may be provided during injection molding of the nozzle cap such that the indicia "OFF", "STREAM" and "SPRAY" are formed using the same thermoplastic material as the remainder of the nozzle cap, but the indicia project slightly from the outer surface of each flat wall of the nozzle cap. In this way, the indicia are formed as a relief on each of the four flat surfaces of the nozzle cap to make the indicia conspicuous and visible to the operator.

One advantage of the above-described prior art in the manufacture of nozzle caps is the low cost, so that the indicia can be formed in a single, simultaneous process step in the molding operation. However, the nozzle covers of the prior art also have disadvantages: the indicia or writing on the flat side wall of the nozzle cap is made of the same thermoplastic material as the remainder of the cap and therefore cannot be contrasted to enhance visibility of the indicia.

Furthermore, the thermoplastic material forming the indicia is often slippery when touched by a wet hand during use of the trigger sprayer. Because of the relatively small size of the nozzle cap (particularly for users with large hands), it is difficult for the user to firmly grip the nozzle cap while holding a pair of opposing sidewalls for rotation of the nozzle cap.

The above-mentioned marks such as "OFF", "STREAM" and "spread" are often replaced by marks in the form of international symbols, such as "OFF" by "X", STREAM by a number of dots or the like forming a narrower cone, and "spread" by a number of dots or the like forming a wider cone. Alternatively, foreign language or symbols may be provided as indicia applied to the nozzle cap of the trigger sprayer. Also, it is known to provide indicia on the nozzle cap by stamping, which may be in a color that contrasts with the nozzle cap itself, or to apply indicia to the flat smooth outer surface of each wall of the nozzle cap. The stamped indicia generally do not project above the flat smooth surface of the wall of the nozzle cap, but rather provide a clear indication to the user of the rotational position of the nozzle cap by contrast in color. However, such a method has a disadvantage in that the nozzle cover requires a two-process for manufacturing, which increases the cost in terms of manufacturing time and materials.

It would be desirable to be able to modify the nozzle cap to enhance the grippability of the walls of the nozzle cap; at the same time, it is desirable to improve the visibility of the indicia to enable high speed manufacturing while saving costs.

Disclosure of Invention

It is an object of the present invention to improve the manual rotation of the nozzle cap of a trigger actuated pump sprayer to make the sprayer easier to use and handle when manipulating the nozzle cap between the open and closed positions. The relief print applied on the outer surface of the flat wall of the cap, representing the marks relating to the open and closed positions of the cap, is modified so as to make the marks more visible and at the same time more pleasant to the touch, also being non-slip in case of wetting; while improving the grasping nozzle cap operation for rotating the nozzle cap between the open and closed positions. The above object is achieved by an operation using a single process in the nozzle manufacturing process, and enables low-cost and rapid manufacturing.

In achieving this general objective, a nozzle cap according to the present invention is manufactured using one of the well-known two-shot techniques of multi-material injection molding, wherein a preform is molded from a first thermoplastic material, then allowed to cool to ensure that it can act as a mold, and then an additional thermoplastic material is co-injected into the mold formed from the first material so that the two materials are securely fused together.

Furthermore, according to the invention, the second thermoplastic material may be of a different colour and/or more resilient than the first thermoplastic material, in order to improve the nozzle cap, reinforcing the indicia, so that it is more recognisable and/or less prone to slipping.

The second thermoplastic material, which is co-injected to form the indicia, may protrude from the outer surface of the flat wall of the nozzle cap, so formed as to enhance the tactile properties and to enhance the non-slip properties of the nozzle cap.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

Drawings

FIG. 1 is a perspective view of a nozzle cap for a trigger operated pump sprayer constructed in accordance with the present invention;

FIG. 2 is a view similar to FIG. 1 of the nozzle cap formed from the first thermoplastic material prior to co-injection molding of the second thermoplastic material with the first thermoplastic material;

FIG. 3 is a cross-sectional view taken substantially along line 3-3 of FIG. 1, illustrating the manner in which the first thermoplastic material and the second thermoplastic material are co-injected during manufacture of the nozzle cap of FIG. 1;

fig. 4 is a side view of a portion of a trigger operated pump sprayer including a nozzle cap constructed in accordance with the invention of fig. 1.

Detailed Description

Turning now to the drawings, in which like reference numerals represent similar and corresponding parts throughout the several views. A nozzle cap 10 constructed and manufactured in accordance with the present invention is particularly shown in fig. 1; also as shown in fig. 4, at the end of the discharge tube 12, the nozzle cap 10 is snap fit into place over the nozzle 11, wherein the discharge tube 12 defines a discharge passage 13 of a known trigger actuated pump sprayer, generally designated 14. The sprayer has a trigger 15, which trigger 15 is mounted to a pump body for actuating a pump piston (not shown) within a pump cylinder 16. The nozzle cap 10 has a rotation mechanism cooperating with the end of the plug 17, wherein the plug 17 is used to close and open the discharge channel when the nozzle cap is manually rotated. Such rotary mechanisms are well known and form no part of the present invention and are specifically disclosed in U.S. Pat. No.4,706,888, which is incorporated herein by reference. Further, the nozzle cover 10 is formed with a discharge hole 18, and the discharge hole 18 communicates with the discharge passage through the rotation mechanism.

The nozzle cap comprises a body 19 injection moulded from a first thermoplastic material, for example polypropylene which hardens substantially after moulding. The body 19 includes a first pair of opposed outer flat walls 21, 22 and a second pair of opposed outer flat walls 23, 24 which are interconnected as shown to form a body which is substantially rectangular in cross-section. These four walls support an inner barrel 25, the inner barrel 25 having an inner rim 26 (see fig. 4) that mates with the plug 17. The inner cylinder 25 is closed at its front end by a wall 27, the wall 27 having a discharge orifice 18 formed therein on the axis of the nozzle cap.

According to the invention, the nozzle cover is formed by a method of alternating molding of different materials, also referred to as double injection molding or multi-material injection molding process. The above process is disclosed in greater detail in U.S. patent No.5,439,124, the disclosure of which is incorporated herein by reference in its entirety.

The body 19 of the nozzle cap is injection molded from a first thermoplastic material and a preform is formed in each of the outer surfaces of the walls 21, 22, 23 and 24, respectively. Indicia, such as "OFF" and "STREAM" are formed on the preforms in walls 21 and 24. Although not shown in the figures, the wall 23 also has a preform shaped as a mark indicating the position "SPRAY"; the outer surface of the wall 22 is also formed with a preform portion in the shape of the "OFF" position indicia. Obviously, international labels can be used instead of the open and closed positions, for example "X" instead of "OFF", a narrower cone of dots or the like to denote "STREAM", and a wider cone of dots or the like to denote "spread". Furthermore, foreign language expressions or logos may be used, if appropriate.

The blank 28 forming the letter "OFF" in the outer surface of the wall 21 of the nozzle cap will be described as part of the two-shot moulding process for making the nozzle cap according to the invention, but it should be noted that the blank 29 in the outer surface of the wall 24 and the blanks (not shown) in the outer surfaces of the walls 22, 23 are both formed as "blanks" simultaneously in the manufacturing process. Thus, the body 19 is molded from a first thermoplastic material into a preform with the letters "OFF", "STREAM", "OFF" and "SPRAY", for example, formed in the walls 21, 24, 22 and 23. Thereafter, the preform is sufficiently cooled to ensure that its mechanical strength is stable enough to act as a mold. Thereafter, the mold for molding the preform is at least partially replaced and the final molding is completed by bi-injection molding the additional thermoplastic material or the second thermoplastic material so that the preform partially serves as the mold. During cooling, the two materials are welded together tightly. The second thermoplastic material may be a different color than the first thermoplastic material, or the second thermoplastic material may be an elastomeric material, or the second thermoplastic material may be not only a different color than the first thermoplastic material, but also an elastomeric material. The second thermoplastic material, shown as 31 in fig. 1 and 3, fills cavities 28, 29 for forming lettering in the outer surfaces of walls 21, 22, 23 and 24. The mold plates 32, 33 for forming the preform of the first thermoplastic material are schematically illustrated in fig. 3. The first thermoplastic material may be polypropylene molded into the cavity of a molding assembly, such as those shown at 32 and 33. The lettering 28 and 29 are formed by blocking a portion of the cavity by means of a movable blocking insert or the like, after which the preform of the first thermoplastic material is allowed to cool for a predetermined time. The insert is then removed, whereupon the cavity-type lettering 28 and 29 are formed; thereafter, a second thermoplastic material 31, such as an elastomeric thermoplastic material, is injected into the cavities forming the lettering parts 28 and 29. After cooling the interface of the first and second thermoplastic materials, the first and second thermoplastic materials are bonded together by fusing the melted portions thereof together to achieve a thorough, secure connection.

As shown in fig. 1 and 3, when the second thermoplastic material 31 is bi-injection molded into the cavities 28 and 29, the second thermoplastic material 31 fills the cavity formed by the illustrated lettering and may be flush with (and formed in) the outer surface of the wall of the preform portion; or the second thermoplastic material 31 extends slightly beyond the outer surface of the wall of the preform in which it is formed, for example, slightly outwardly of the outer surface 34 of the wall 21 of the nozzle cap (see fig. 3). In either case, whether flush or projecting outwardly, the second thermoplastic material 31, if elastomeric, provides the operator with a better tactile feel, i.e., softer to the touch; the second thermoplastic material 31 provides a non-slip surface when contacted by an operator for substantially preventing slippage of the operator's fingers on the nozzle cap when the nozzle cap is rotated, particularly when the fingers or nozzle cap are wet. When using a material 31 that is elastomeric and that protrudes, for example, outwardly from the outer surface 34 of the wall, the material is more tactile and softer to the touch, and thus has better anti-slip properties.

If the second material 31 is different in color from the first material forming the body 19 only, the contrasting color between the indicia and the nozzle cap body can be improved so that the indicia is clearly noticeable and easily identifiable even when used in dark areas; in addition to this, there is little, if any, slip resistance. In the above-mentioned case, the advantage of the double injection moulding in the manufacture of the nozzle cap according to the invention is that both the first material and the second material can be applied in a substantially single-step operation, without having to bring the nozzle cap, after having been completely cooled, to a stamping station where the outer wall is stamped with indicia, as described in the prior art.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. 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 (6)

1. A trigger actuated pump sprayer comprising a pump body having a discharge passage terminating in a nozzle at a forward end of the sprayer, a nozzle cap mounted on said nozzle for rotation about a central axis of said nozzle cap between open and closed positions, said nozzle cap having a discharge orifice at said central axis and first and second pairs of opposed flat side walls which together define a rectangular body, at least one of said side walls having indicia thereon for indicating a selected rotational position of said nozzle cap relative to said nozzle, said nozzle cap including a body structure of a first rigid, molded material portion defining each of said side walls and a discharge passage terminating in the discharge orifice, the indicia on said side walls being defined by recessed regions forming a mold, and the nozzle cap further includes a second portion of molded material that is overmolded with the first portion of molded material in the recessed area of the blank such that the first and second portions of molded material are fused together at their interface.

2. The pump sprayer according to claim 1, wherein the second portion of molded material projects outwardly beyond an outer surface of one of the side walls.

3. The pump sprayer according to claim 1, wherein each of said sidewalls has a respective said indicia for indicating a selective rotational position of said nozzle cap relative to said nozzle.

4. The pump sprayer according to claim 3, wherein the second portion of molded material in each preform projects outwardly beyond the outer surface of the respective sidewall.

5. The pump sprayer according to claim 2, wherein the first portion of molded material comprises a thermoplastic material and the second portion of molded material comprises a thermoplastic elastomer material to form a non-slip grip that can be grasped by the fingers of an operator of the sprayer.

6. The pump sprayer according to claim 4, wherein the first portion of molded material comprises a thermoplastic material and the second portion of molded material comprises a thermoplastic elastomer material to form a non-slip grip that can be grasped by the fingers of an operator of the sprayer.