JPH0216454B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to dispensers, and more particularly to handheld dispensing devices capable of repeatedly dispensing precise amounts of liquid.

Various types of devices have been devised in the past for repeatedly dispensing precise amounts of liquid. Many forms of hand-held droppers can accomplish this task. However, in many cases it is necessary to refill the dropper after each use or to provide a number of different stopping positions for the plunger of the dropper.
This latter method requires special adjustments by the user and generally yields only a very limited number of samples for each full stroke of the plunger.

In response to the need for repeatable liquid delivery devices capable of dispensing large numbers of samples without refilling, various types of plunger bottle dispensers have been devised. For example, there are those disclosed in US Pat. No. 3,191,807, US Pat. No. 3,430,813, US Pat. Typically, these devices include a plunger and a first check valve that allows liquid to flow back when the plunger is released (i.e., returned under the action of a bias spring). Let it flow into the chamber. A second check valve allows liquid to drain when the plunger is depressed. The relatively large capacity bottle then acts as a source of liquid from which liquid is drawn by the first check valve. Although this type of bottle dispenser device has been found to work satisfactorily in some applications, there are some inconveniences associated with the size and volume of the bottle;
You will also need to frequently bring test tubes or other containers near where the bottle is located.

In the device for pipetting and/or diluting disclosed in my U.S. Pat. No. 4,046,291, the source of liquid reagent is integral to the device itself, i.e., the source of reagent is It is contained within an enclosed enclosure defining a rear chamber surrounding the plunger. The plunger has a communication passageway between this rear chamber and a front chamber forward of the plunger. A one-way valve is provided in this communication passage to restrict flow so that only flow from the rear chamber toward the front chamber occurs. Releasing the plunger draws liquid reagent into the front chamber and expelling it when the plunger is depressed. Each time the plunger is released, a portion of reagent is drawn into the front chamber for the next delivery.

The object of the present invention is to
The object of the present invention is to provide an improved dispensing device of the type disclosed in US Pat. No. 4,046,291. In particular, it is an object of the present invention to be able to reproducibly deliver precise quantities of liquid reagents, to be easy to have a large source of such reagents, and without requiring particular manual dexterity. To provide a handheld dispenser that is easy to handle and use.

The improved dispensing device of the present invention has a tubular body with front and rear ends, the body having a central bore and the front end narrowing to form a tip. A piston can slide within this central bore, and the bore cavity in the body forward of the piston defines a front chamber.
An enclosure mounted with and movable with the piston defines a rear chamber. The rear chamber, preferably a bottle, is removably mounted to the rear of the piston. The piston has a communication passageway between the front chamber and the rear chamber. The first one-way valve device inhibits flow in the communication passageway so that only flow from the rear chamber toward the front chamber occurs. The second one-way valve arrangement also inhibits flow between the front chamber and the tip so that only flow from the front chamber toward the tip occurs.

In a preferred embodiment of the invention, a tubular sleeve is connected at its rear end to the rear of said piston. The sleeve is configured to slide over the outer surface of the body. In this embodiment, the tip preferably engages the container into which liquid is to be injected, so that when the sleeve and the piston connected thereto are moved by hand in the direction of the container, the tip is inserted into the container. Allows to be supported in the mouth.

The structure of the invention is particularly easy to load, eg to attach bottles with screws. Also, the dispensing operation is easily performed by grasping the sleeve with the hand and pushing down. No thumb action on the plunger is required. The tip serves both to engage the receiving container and to center the dispensing tip in the mouth of the receiving container.

Other features and advantages of the invention will become more apparent from the following detailed description with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, one embodiment of a dispensing device 10 according to the present invention is shown. The tubular body 20 tapers at its front end to form a dispensing tip 21. In the example diagram of FIG. 1,
The piston is shown in its normal retracted position, and in the exemplary view of FIG. 2, the piston is shown in its depressed position. The drilling cavity in front of the piston 30 is called the front chamber 11. There is an annular connecting piece 40 mounted behind the piston 30 or formed integrally with the piston. The connecting piece 40 has an inner thread 41 at its rear inner end and an outer thread 42 at its front outer end. The rear thread 41 of the connecting piece 40 receives the external thread 111 of the opening 112 of the vial 110 containing the reagent, which acts as a rear chamber. gasket 4
3 acts as a suitable seal. bottle 110
has one small air intake vent valve 115;
This is a resilient lip valve in this embodiment. The cylindrical sleeve 50 has an internal thread 51 at its rear end and an internal thread 52 at its front end. Since the rear inner thread 51 engages with the front thread 42 of the connecting piece 40,
Sleeve 50 is securely coupled to piston 30 and is movable therewith. Front internal threads 52 of sleeve 50 engage external threads 61 of adjustable stop ring 60. By threading the adjustable stop ring 60, the volume of the front chamber 11, ie, the amount of fluid dispensed at one time, is adjusted.

The piston 30 has a communication passage 31 between the mouth of the bottle 110 and the front chamber 11. One-way valve 35 is located at the front end of piston communication passage 31 to restrict fluid flow within the passage in the direction from bottle 110 into front chamber 11 . In this embodiment, the one-way valve 35 is a resilient lip valve and is held in position by an annulus 36 that is press fit into a recess in the front of the piston 30.

Another one-way valve 25 is mounted immediately forward of the front chamber 11 and allows liquid flow only in the direction from the front chamber 11 to the tip 21 and the outside environment. In this embodiment, this one-way valve 25
is a sleeve type check valve, and it has a valve body 2.
6, the central hole 27 of which has a small side hole 2
Connects to 8. A flexible sleeve 29, typically made of rubber, encloses the valve body 26. Main body 2
The part of the sleeve surrounding the top of 6 acts as a seal. The liquid in the front chamber 11 can be forced into the tip 21 through the perforations 27, side holes 28, and further through the lower part of the sleeve 29, which is slightly expanded outwards. However, fluid within the chip cannot flow back into chamber 11. After all, sleeve 2
9 is in close contact with the main body 26 in this case.

A coil spring 70 surrounds the piston 30. This spring is restrained at its upper end by the connecting piece 40 and at its lower end by a rim 81 projecting outward from the ring body 80. Ring body 80
is fixed to the rear end of the main body 20. The annulus 80 also has an inwardly extending rim 82 under which a grommet 83 is held that connects the piston 30.
and the tubular body 20 are sealed. spring 70
normally forces the piston 30 rearwardly against the body 20, thereby raising the piston 30 to a "release" position at the top of its stroke. The upper limit of the piston determines the volume of liquid delivered from the front chamber 11 when the piston is subsequently depressed, and it is the adjustable stop that abuts the rim 81 at the top of the piston stroke.・Ring 60
determined by the position of

In the embodiment of FIGS. 1 and 2, the outer surface of the tip 21 is made large enough at its end 200 to fit into the mouth of a test tube 300 or other container into which a quantity of reagent is to be dispensed. Make it engage. An alternative chip 210 is illustrated in FIG. These chips may be formed integrally with the device (eg, FIG. 3), or even as a separate unit that is coupled to the tip of a conventional device.

To illustrate the operation of the dispensing device of the invention, consider that the piston 30 is at the top of its stroke (in the released position) and that the front chamber 11 is filled with the liquid to be dispensed. The user places the tip of the device against the mouth of a test tube 300 into which a certain amount of reagent is to be delivered. The sleeve 50 of the device is grasped and pushed downward to cause a forward stroke of the piston connected to the sleeve. Thereby, the reagent in the front chamber is dispensed into the receiving test tube 300.
One-way valve 35 prevents backflow to the liquid source. Second
The figure shows the depressed position of the piston,
Spring 70 is compressed. Upon releasing the hand force at the bottom of the stroke, the spring returns the piston 30 and sleeve 50 to their normal released position at the top of the stroke. As the piston returns to the top of its stroke, due to atmospheric pressure, fluid is forced from within the bottle through the communicating passage 31 in the piston 30 and through the one-way valve 35 into the front chamber 1.
Drawn into 1. During this operation, a displacement amount of air enters through the vent valve 115 of the bottle 110. A one-way valve 25 in the tip 21 prevents air from entering the front chamber from the tip.

Referring to FIG. 4, another embodiment of the invention is shown, which operates in a similar manner to the previous embodiment, but with some structural differences.
In the embodiment of FIG. 4, the piston 30 includes a relatively narrow diameter rod portion 430A and a relatively large head 430B, the head containing a lip valve 35 on one side. In this embodiment, the outer sleeve 450 also moves with the bottle 410 and the piston 430, with the sleeve 450 extending inwardly at its front end to direct the upward stroke of the sleeve (and thus the upward stroke of the piston). forming a limiting device. The spacer element 405 is
There are optional dimensions that can be used to adjust the upper limit of stroke in this embodiment.

In the embodiment of FIG. 4, bottle 410 is mated with bottle cap 406 and bottle cap 406
is held against the rear edge of the sleeve 450 by a threaded cap retaining element 407. The top of the piston rod 30 is press fit into an adjustment screw 408, which
Fits into cap holder 407. Adjustment screw 40
The top of 8 includes a diametrical slot (not shown) into which a screwdriver can be inserted for adjustment. An O-ring 409 is provided to seal between the adjustment screw 408 and the cap retainer 407. A seal 491 is provided at the mouth of the bottle 410. The spring 470 is connected to the piston rod 43
0A, washer 492 and adjustment screw 408
is held between.

In the embodiment of FIG. 4, ventilation is provided by a small tube 495 which can have a small one-way lip valve 496 at its exposed end. Therefore, in the embodiment of FIG. 4, there is no need for the bottle itself to have a vent valve. In addition, the operation of refilling the liquid into the bottle is performed with the entire device in an inverted position.
Of course, this can be done by removing the bottle.

The manner in which the structural elements described above are formed is
There are various types. The embodiments of FIGS. 1 and 4 consist essentially of molded or machined plastic parts (apart from resilient valve materials, springs and sealing materials, etc.), but are made of stainless steel or other materials. Other suitable materials can also be used.

Although the invention has been described with respect to specific embodiments, many modifications that are within the spirit and scope of the invention will occur to those skilled in the art.
For example, although representative tip shapes have been disclosed, it will be appreciated that other tip shapes suitable for engaging the mouth of the receiving container may be used.

[Brief explanation of drawings]

1 is a vertical cross-sectional view of a dispensing device according to one embodiment of the invention, showing the piston in the released or returned position; FIG. 2 is a cross-sectional view similar to FIG. 1, but with the piston depressed; shown in the indicated position,
FIG. 3 illustrates a modified tip of the present dispensing device, and FIG. 4 is a vertical sectional view of a dispensing device according to another embodiment of the invention. 10... Distribution device, 11... Front chamber, 2
0... Tubular body, 21... Distribution tip, 25... One-way valve, 26... Valve body, 27... Center perforation, 28...
... Side hole, 29 ... Flexible sleeve, 30 ... Piston, 31 ... Communication passage, 35 ... One-way valve, 36
... Ring body, 40 ... Annular connecting piece, 41 ... Inner thread, 42 ... Outer thread, 43 ... Gasket, 50 ... Cylindrical sleeve, 51, 52 ... Inner thread, 60 ... Adjustable stop ring, 6
1...Outside thread, 70...Coil spring, 80...
... ring body, 81 ... outer rim, 82 ... inner rim,
83... Grommet, 110... Bottle (rear chamber), 111... Screw thread, 112... Bottle mouth,
115... Air intake vent valve, 200... Chip end, 300... Test tube.

Claims (1)

[Claims] 1 a tubular body 20 having a front end and a rear end and having a central bore with a tapered tip to form a tip 21; a piston 30 capable of sliding within said bore; a piston 30 whose perforation cavity in the body at the front defines a front chamber 11; a removable body mounted with and movable with said piston and defining a rear chamber; a sealed bottle 110, the piston having a communication passageway 31 between the rear chamber and the front chamber, the communication passage being such that only flow from the rear chamber towards the front chamber occurs. a first one-way valve device 35 that suppresses the flow in the passage;
a second one-way valve device 25 coupled to the piston and configured to restrict flow between the front chamber and the tip so that only flow from the front chamber toward the tip occurs; a cylindrical sleeve 50 configured to slide over an outer surface of the tubular body; and a spring 70 disposed between the piston and the body to urge the piston rearwardly relative to the tubular body. a stop ring 60 adjustably mounted between the cylindrical sleeve and the tubular body to determine the volume of the front chamber.