Patent Application
20100111732
The present invention generally relates to reciprocating piston liquid pumps. More particularly, this invention relates to a reciprocating piston liquid pump that is actuated by a rotating actuator mechanism. The rotating actuator mechanism converts a linearly actuation motion in a horizontal plane to linear motion in an off-vertical plane to advance the piston of the piston pump and cause the piston pump to advance product.
Reciprocating piston liquid pumps are well known in the art, and are employed to pump and/or dispense various products. Many well known reciprocating piston liquid pumps are found in desktop dispensers wherein a dispensing spout is pressed down to dispense product onto a hand held under the dispensing spout. Soaps, lotions and sanitizers are among the most common products dispensed with such pumps.
These pumps are also employed in environments other than desktop dispensers. For instance, it is common to find a reciprocating piston liquid pump in a wall-mounted dispenser wherein a push bar is pressed to actuate the pump and dispense product onto a hand held under the push bar. In these dispensers, the push bar typically pivots at a pivot point and provides arms that operatively engage the reciprocating piston of the pump such that pressing on and releasing the push bar causes the reciprocating movement of the piston necessary for dispensing the product from a product container to which the pump is secured. Because the stroke length of the reciprocating piston is dictated by the distance the push bar arms move, the desired stroke length can be achieved either by designing the push bar to pivot through a necessary arc, or by sizing the arms to engage the pump at a significant distance fro the push bar, thus permitting a smaller arc. The arms extending from the push bar engage a linearly moving actuating carriage engaging the reciprocating piston, so, with longer arms, more linear motion is achieved with a smaller push bar arc. However, because lever arms are employed between the push bar and the actuation carriage, the mechanical advantage offered by the push bar must be significant enough that the user of the dispenser does not have to push too hard to dispense product. Thus, the push bar of the prior art is typically long in length and travels through a significant rotational arc. As a result, the dispenser can take up a larger footprint.
The present invention seeks to address the need in the art for actuating mechanisms for reciprocating piston liquid pumps for wall-mounted dispensers wherein the push bar dimensions are smaller and the arc length is decreased such that the wall-mounted dispenser can occupy a smaller footprint.
In general, this invention provides a reciprocating piston liquid pump and a piston driver mechanism. The reciprocating piston liquid pump includes a piston chamber and a piston reciprocating in the piston chamber from an unactuated position to an actuated position, with movement of the piston from the unactuated position to the actuated position causing the reciprocating piston liquid pump to advance product. The piston driver mechanism includes a first driver member having an axis and a sloped circumferential surface extending along its axis, and a second driver member having an axis and a sloped circumferential surface extending along its axis. The first and second driver members are aligned along their axes and mate at an unactuated position along at least a portion of their sloped circumferential surfaces such that rotation of one of the driver members about its axis relative to the other of the driver members causes the second driver member to advance away from the first driver member toward and actuated position along its axis through the interaction of the sloped circumferential surfaces. This movement also causes movement of the piston to its actuated position, thus advancing product.
In
In this embodiment, an over cap 22 engages the neck 20 at mating threads, and a reciprocating piston liquid pump 24 extends through the over cap 22 to close off the open top provided by the neck 20. The reciprocating piston liquid pump 24 includes a reciprocating piston member 26 having an outlet passage 28, and the reciprocating piston member 26 is moved against the bias of a spring 29 to dispense the liquid S retained in the container 12. More particularly, the reciprocating piston member 26 interacts with both a liquid chamber 30 and an air chamber 32 such that, as the reciprocating piston member 26 is moved against the bias of the spring 29, both liquid S and air G are advanced into and through the outlet passage 28 in order to create a foam product. Reciprocating piston pumps of this type are well known, and the particular structure to be employed for a reciprocating piston liquid pump 24 is not material to this invention. Indeed, the main structures of a prior art reciprocating piston liquid pump and container could be employed, to be modified to include the piston driver mechanism in accordance with this invention. The reciprocating piston liquid pump 24 is provided with appropriate valves and, preferably, a screen bounded mixing cartridge, as known, such that liquid S is dispensed as foam at outlet 34 of the outlet passage 28 when the reciprocating piston 26 is forced upwardly in the direction of arrow A. Although the present invention shows a foam pump, it should be appreciated that a common, non-foam reciprocating piston liquid pump could also be modified with the piston driver mechanism in accordance with this invention.
The body member 36 of the reciprocating piston liquid pump 24 provides the liquid chamber 30 and the air chamber 32 with which the reciprocating piston 26 interacts to advance and dispense foam. This body member 36 is secured to the top of the neck 20 of the container 12 by a flange 38, which is wedged against the open top of the neck 20 by the over cap 22. The over cap 22 includes a drive member cap 40 extending axial from the container cap portion 42 to extend alongside and at least partially surround the reciprocating piston 26. A resistance flange 44 extends radially inwardly from the drive member cap 40 to lie in close proximity to the dispensing spout 46 extending from the piston portion 26. An annular gap 48 is formed between the over cap 22 and the reciprocating piston 26 and dispensing spout 46 and the driver mechanism 49 of the pump and driver mechanism 10 is positioned therein.
Referring to
The first driver member 50 and the second driver member 52 are axially aligned to mate in the unactuated position along at least a portion of their respective sloped circumferential surfaces, with the first sloped circumferential surface 60 of the first drive member 50 mating with the first sloped circumferential surface 78 of the second drive member 52, and the second sloped circumferential surface 66 of the first drive member 50 mating with the second sloped circumferential surface 84 of the second drive member 52. In the embodiment shown, the first and second drive members 50, 52 mate circumferentially along their respective first axial extensions 56, 74 and second axial extensions 58, 76 and each sloped circumferential surface 60, 66, 78, 84 has a similar slope such that they together form a completed tubular construct. However, the first and second drive members 50, 52 need not nest together in such an intimate fashion, it being sufficient that they at least mate along a portion of their respective sloped circumferential surfaces. This will be appreciated as the functioning of the driver mechanism 49 is disclosed.
In the unactuated position shown in
As the first drive arm 90 and second drive arm 94 are pushed, they rotate about their axes, and this causes the second driver member 52 to advance away from the first driver member 50, which is held in place due to the interaction of the contact surface 51 with the resistance flange 44 of the over cap 22. The advancement of the second driver member 52 causes the reciprocating piston 26 to be moved against the bias of a spring 29 to advance and/or dispense the liquid S retained in the container 12. The first and second arm apertures 92 and 96 are sized appropriately to permit radial movement of the first drive arm 90 and to permit radial and axial movement of the second drive arm 94. Once pressure is released from the first and second drive arms 90, 94, the spring 29 will return the pump and driver mechanism 10 to the unactuated position, ready for another actuation. In a wall-mounted dispenser embodiment, the pump and driver mechanism 10 would be included as part of a refill unit including the container of liquid S and this refill unit would be held by a wall-mounted dispenser housing. The refill unit would mount inside of the housing such that the common push bar would engage the first and second drive arms 90, 94 to push them linearly when the push bar is pivoted to dispense product as is common in wall-mounted dispensers. As an alternative, the first and second drive arms 90, 94 can be pushed by electronic elements actuated by a touchless sensor as is commonly employed in certain wall-mounted dispensers.
It will be appreciated that first and second driver arms 90, 94 are not required, inasmuch as it would be possible to provide only one drive arm. With only one drive arm being linearly actuated, the sloped circumferential surfaces of the first and second drive members would still advance away from each other as seen in
Referring now to
Thus, an over cap 122 engages a neck 120 at mating threads, and a reciprocating piston liquid pump 124 extends through the cap 122 to close off the open top provided by the neck 120. The reciprocating piston liquid pump 124 includes a reciprocating piston member 126 having an outlet passage 128, and the reciprocating piston member 126 is moved against the bias of a spring 129 to dispense the liquid S retained in the container 112. More particularly, the reciprocating piston member 126 interacts with both a liquid chamber 130 and an air chamber 132 such that, as the reciprocating piston member 126 is moved against the bias of the spring 129, both liquid S and air are advanced into and through the outlet passage 128 in order to create a foam product. Although the present invention shows a foam pump, it should be appreciated that a common, non-foam reciprocating piston liquid pump could also be modified with the piston driver mechanism in accordance with this invention.
The body member 136 of the reciprocating piston liquid pump 124 provides the liquid chamber 130 and the air chamber 132 with which the reciprocating piston 126 interacts to advance and dispense foam. This body member 136 is secured to the top of the neck 120 of the container 112 by a flange 138, which is wedged against the open top of the neck 120 by the over cap 122. The over cap 122 includes a drive member cap 140 extending axial from the container cap portion 142 to extend alongside and at least partially surround the reciprocating piston 126. A resistance flange 144 extends radially inwardly from the drive member cap 140 to lie in close proximity to the dispensing spout 146 extending from the piston portion 126. An annular gap 148 is formed between the over cap 122 and the reciprocating piston 126 and dispensing spout 146 and the driver mechanism 149 of the pump and driver mechanism 110 is positioned therein.
The driver mechanism 149 is substantially identical to the driver mechanism 49 disclosed above with respects to
As seen in
In light of the foregoing, it should be appreciated that the present invention advances the art by providing a reciprocating piston liquid pump and piston driver mechanism particularly useful for providing wall-mounted dispensers having push bars that take up a smaller footprint. However, this invention is not limited to wall-mounted dispensers employing push bars. The scope of this invention will be defined by the following claims.
