Viscous liquid dispenser

A viscous liquid dispenser is characterized by a yieldable lever arm pivotally connected within a casing. The lever arm carries a rigid dispensing block thereon. In response to the imposition of an actuating force to the lever arm, the arm pivots to bring the tip of the dispensing block into contact with a resilient flexible tube extending from a viscous liquid reservoir. The resilient tube is constricted between the tip of the dispensing block and a predetermined impact point located on a movable back-up block provided adjacent to the resilient tube and opposite from the dispensing block. The lever arm yieldably responds to the continued application of an actuating force to compress a portion of the resilient tube immediately below the constriction between the dispensing block and a predetermined dispensing surface disposed on the back-up block. The compressive force thereby imparted to the entrapped viscous liquid unseats a spring-biased long-throw ball check valve and to expel a predetermined quantity of viscous liquid from the resilient tube. Upon cessation of the actuating force, the yieldable lever arm and the resilient tube return to their unstressed states, and the ball check valve returns to its seat, the suction created thereby draws any remaining viscous liquid back into the lower portion of the resilient tube. The magnitude of the volume of viscous liquid dispensed by each actuation of the yieldable lever arm is able to be regulated by moving the back-up block with respect to the dispensing block.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to viscous liquid dispensers, and, in particular, to 
a viscous liquid dispenser having a yieldable dispensing lever arm and 
arrangement for varying the volume of viscous liquid expelled. 
2. Description of the Prior Art 
Devices for the dispensing of a viscous liquid or paste-like product are 
known in the art. These devices may, for example, use a roller moving over 
a resilient tube that is connected to a viscous liquid reservoir to expel 
viscous liquid from the tube. As the roller advances, the resilient tube 
is progressively compressed between the roller and a suitably disposed 
back-up block. Examples of such prior art devices are U.S. Pat. No. 
2,113,002, issued to Hefti, and U.S. Pat. No. 3,006,832, issued to 
Rosetti. 
Alternatively, other prior art dispensing devices may utilize contact 
members which are first moved to constrict a portion of a resilient tube. 
Then, the contact member is forced into compressive contact with the 
resilient tube to cause viscous liquid to be expelled therefrom. Examples 
of the latter type viscous liquid dispenser are U.S. Pat. No. 3,741,439, 
issued to Vehrs, and U.S. Pat. No. 3,870,201, issued to Asplund. It is 
usually a problem of prior art devices of any type to have an unsightly 
and unsanitary coagulated mass of viscous liquid remaining at the orifice 
of the resilient tube left from previous dispensations of viscous liquid 
therefrom. 
Both of the last-mentioned patents provide a contact member which is 
brought into compressive contact with a resilient tube extending from a 
viscous liquid reservoir to expell viscous liquid from the resilient tube. 
However, neither of these last-mentioned patents provide any mode of 
controlling the volume of liquid expelled during the actuation stroke of 
the apparatus. Also, neither of the last mentioned patents utilize a 
resiliently yieldable actuating lever arm to bring the compressing member 
into compressive contact with the resilient tube. Yet further, neither of 
these last-mentioned patents disclose suction means for drawing excess 
viscous liquid back into the resilient tube to prevent the coagulation of 
excess viscious liquid. 
It would be advantageous to provide a viscous liquid dispensing apparatus 
having a suitable mechanism provided therein for varying the magnitude of 
viscous liquid expelled during the actuation stroke thereof. It would be 
of further advantage to provide a viscous liquid dispensing device 
utilizing a yieldable dispensing lever arm, actuation of which initially 
contacts a portion of a rigid dispensing block into constricting contact 
with the resilient tube and further actuation thereof causes yieldable 
deformation of the lever arm to compress a portion of the resilient tube 
below the constriction between the dispensing block and a compression 
surface on an oppositely disposed back-up block. 
It is advantageous to provide a viscous liquid dispensing device including 
suitable suction means for drawing excess viscous liquid into the 
resilient tube to thereby prevent the unsightly and unsanitary coagulation 
of viscous liquid common in prior art dispensing apparatus. Thus, it is of 
further advantage to provide suction means in the form of a long-throw 
ball check valve such that cessation of an actuating force on the 
yieldable dispensing lever arm permits a spring bias element to overcome 
compressive forces within the viscous liquid to urge the ball to the 
closed position and to generate a suction force to draw viscous liquid 
into the downstream terminus of the resilient tube and thereby prevent 
dripping and coagulation of the viscous liquid product. 
SUMMARY OF THE INVENTION 
This invention relates to a viscous liquid dispensing apparatus having a 
viscous liquid reservoir suitably mounted within an appropriate housing or 
casing with a resilient tube attached thereto. Pivotally disposed within 
that casing is a yieldable lever actuating arm having a substantially 
rigid dispensing block mounted thereon. Movably disposed within the casing 
so as to bracket the resilient tube and oppositely face the dispensing 
block is a back-up block fabricated of a suitable, substantially rigid 
material. The yieldable lever arm responds to the imposition of an 
actuating force thereon by pivoting to bring the tip of the dispensing 
block into contact with a portion of the resilient tube to constrict the 
resilient tube between the dispensing block and the back up block and 
entrap a predetermined volume of viscous liquid downstream of the 
constriction. Continued application of an actuating force generates a 
rocking motion of the yieldable lever arm as the yieldable lever arm is 
deformed to bring the dispensing block into contact with the resilient 
tube and to compress a portion of the resilient tube immediately 
downstream of the constriction between the dispensing block and a 
compression surface disposed on the back-up block. Imposition of a 
compressive force on the entrapped viscous liquid by the cooperative 
action of the dispensing block and the back-up block overcomes the bias 
force of a spring bias element normally holding a long-throw ball check 
valve in the seated position. The long-throw ball check valve responds to 
the compressive force of the viscous liquid to unseat and thereby permit a 
predetermined volume of viscous liquid to be expelled from the downstream 
orifice of the resilient tube. 
Upon release of the actuating force, the yieldable lever arm is restored to 
its undeformed condition and the resilient tube returns to its natural 
condition to open the constriction and to draw another charge of viscous 
liquid from the reservoir into the resilient tube. Simultaneously, 
cessation of the actuating force permits the spring bias to overcome the 
compressive force within the viscous liquid to urge the long-throw ball 
check valve toward the seated position. Return of the long-throw ball 
check valve to the seated position generates a suction force which draws 
any viscous liquid present at the orifice of the resilient tube into the 
lower end of the tube to prevent unsightly accumulation and coagulation of 
the viscous liquid.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Throughout the following descriptions, similar reference numerals refer to 
similar elements in all figures of the drawings. 
Referring to FIGS. 1 and 2, a plan and sectional view of the viscous liquid 
dispensing device are shown embodying the teachings of this invention, the 
dispensing device being generally indicated by reference numeral 10. The 
viscous liquid dispensing device 10 generally includes a casing 12 having 
a back cover 14 of generally rectangular shape and a correspondingly 
shaped front cover 16. The front cover 16 has extending arms 18 which are 
pivotally connected to the lower portion of the back cover 14 to permit 
the front cover 16 to swing away therefrom. Suitable locking means 20 are 
provided to expedite the opening and closing of the dispensing device 
casing 12, the locking means 20 being any suitable key lock device or the 
like. 
The back cover 14 has first and second ledges 22A and 22B extending 
inwardly and substantially perpendicularly to the lengthwise dimension 
thereof. The ledges 22 are supported by perpendicularly extending support 
girders 24A and 24B. Disposed a predetermined distance below the ledges 
22, a partition 26, having a circular recess 28 therein, is provided. The 
curved underside 30 of the partition 26 slopes toward the back cover 14 
and defines a region 34 into which an operator's hand or force actuator 
may be inserted. 
A suitable viscous liquid reservoir 40 of any predetermined shape (although 
conveniently shown to be substantially rectangular in volume so as to be 
received within the casing 12) is provided and rests upon the ledges 22A 
and 22B within the casing 12. A resilient tube 42, fabricated from a 
suitable material such as neoprene rubber, although it is understood that 
any other suitable material may be used, is connected with its first end 
in fluid communication with the reservoir 42. The tube 42 extends axially 
through the interior of the casing 12 between the ledges 22 and the 
circular recess 28. The resilient tube 42 terminates in a second, 
downstream end 46, the end 46 being disposed just beneath the lower end of 
the circular recess 28 in the partition 26. Provided in the second end 46 
of the resilient tube 42 is an anti-drip, long-throw, ball-check valve 48, 
which is described in more detail herein. 
As seen in FIGS. 1 and 2, an actuating lever arrangement generally 
indicated at 52 is provided. The lever arrangement 52 includes an 
extending dispensing arm 54 fabricated of a suitable yieldable material 
such as nylon, although other suitably flexible materials may be used. The 
lever arm 54 is supported for movement within the casing 12 by first and 
second struts 56A and 56B, respectively, the struts 56 being pivotally 
mounted to the support girders 24 of the ledges 22A and 22B. As seen, the 
dispensing lever arm 54 carries a substantially rigid, non-resilient, 
dispensing block 58, the dispensing block 58 being located within the 
casing and occupying a portion of the space between the lower surface of 
the ledges 22 and the upper surface of the partition 26. The dispensing 
block 58 has a tip 59 provided thereon for a purpose which will be made 
clear herein. In the normal, non-dispensing position illustrated in FIGS. 
1 and 2, the dispensing block 58 is canted so that the substantially flat 
dispensing surface 60 thereon is inclined with an axis 62 extending in the 
downstream direction through the resilient tube 42. The free end 64 of the 
yieldable extending dispensing arm 54 of the lever arrangement 52 is 
disposed within the region 34 and is accessible to receive an operator's 
fingers or to receive an actuating force imparted thereto. 
Movably mounted on the interior surface of the front cover 16 of the casing 
12 is a substantially rigid, non-resilient, back-up block 66. In the 
assembled relationship illustrated in FIGS. 1 and 2, the back-up block 66 
is disposed to occupy a portion of the volume between the lower surface of 
the ledges 22 and the upper surface of the partition 26 and has a 
transverse width of sufficient magnitude to encompass the transverse width 
of the resilient tube 42. When assembled, the back-up block 66 is located 
opposite from the dispensing block 58 and presents a compression surface 
68 facing the dispensing surface 60 of the dispensing block 58. As is made 
more clear herein, the cooperative association of the dispensing surface 
60 and a predetermined portion of the compression surface 68 compresses 
the resilient tube 42 therebetween (upon activation of the lever 
arrangement 52) to cause a measured amount of viscous liquid to be 
expelled from the second end 46 of the resilient tube 42. Movement of the 
back up block 66 within the casing 12 has the effect of varying the 
magnitude of the compression surface 68 on the back up block 66 that 
cooperates with the dispensing surface 60 on the dispensing block 58 to 
thereby vary the amount of viscous liquid expelled at each operation of 
the lever arrangement 52. 
Means are provided to permit relocating movement of the back-up block 66 
within the casing 12. As an example, the interior of the front cover 16 is 
provided within runners 70A and 70B. The runners have a plurality of sets 
of slots 71A-71C therein which receive flanges 72 disposed on the back-up 
block 66. By inserting the flanges 72 into a predetermined one of the sets 
of slots 71, the degree of cooperative association between the dispensing 
surface 60 on the dispensing block 58 and the compression surface 68 on 
the back-up block 66 may be varied, to variably control the amount of 
viscous liquid expelled. Of course, it is understood that any suitable 
method of varying the location of the back-up block 66 with respect to the 
casing 12 and with respect to the dispensing block 58 is within the 
contemplation of this invention. 
The front cover 16 may conveniently be provided with a port 73 which 
permits an outside observer to monitor the progressive decrease in level 
of viscous liquid within the reservoir 40 as the device 10 is operated. 
When the level of viscous liquid within the reservoir 40 indicates that a 
refill is required, the locking means 20 may be actuated to permit the 
front cover 16 to pivot away from the back cover 14 to provide access to 
the reservoir 40. The reservoir 40 may have an opening provided therein to 
permit refilling thereof, or, in the alternative, a unitized viscous 
liquid reservoir, complete with an integral resilient tube 42, may be 
provided for simple and efficient insertion onto the ledges 22 within the 
casing 12. While the interior of the front cover 16 is thus exposed, any 
necessary or desired adjustments to the movable back-up block 66 may be 
effected. Closure of the locking means 20 again provides an integral 
housing for the reservoir 40. 
Referring now to FIGS. 3 through 6, sectional views of the dispensing 
device 10 embodying the teachings of this invention are shown which 
diagrammatically illustrate the principles of operation thereof. 
However, before discussing the operative mode of a dispensing device 10 
embodying the teachings of this invention, attention is directed to FIG. 3 
to the second, downstream, end 46 of the resilient tube 40, wherein the 
long-throw ball-check valve 48 is suitably mounted. The ball-check valve 
48 includes an elongated valve housing 76 having a first inlet orifice 78 
and a second, downstream, or outlet, orifice 80. An elongated valve 
chamber 82 has a distended portion 84 which creates a holding space on the 
interior of the housing 76. A ball element 86 is biased toward the closed, 
or seated, position, illustrated in FIG. 3, by a biasing element, such as 
a coil spring 88, mounted on a spring retainer adjacent the outlet orifice 
80. 
The apparatus 10 embodying the teachings of this invention, while in the 
normally unactuated state shown in FIG. 2, is arranged such that viscous 
liquid from the reservoir 40 is drained by force of gravity into the 
resilient tube 42 and completely fills the volume of the tube up to and 
including the point in the resilient tube immediately upstream of the 
ball-check valve 48. In operation, actuation of the extending arm 54 of 
the lever 52 in a direction indicated by arrow 92, in FIGS. 3 through 5, 
causes the lever arrangement 52, and particularly the yieldable extending 
dispensing arm 54 thereof, to pivot in the direction of arrow 93 about the 
attachment between the struts 56 and the girders 24 to move the tip 59 of 
the dispensing block 58 into contact with the exterior of the resilient 
tube 42. 
As seen in FIG. 4, when the yieldable extending arm 54 has pivotally moved 
from its initial position (shown in dot-dash lines) to the position shown 
in solid lines, the resilient tube 42 is constricted between the tip 59 of 
the dispensing block 58 and a predetermined impact point 94 disposed on 
the compression surface 68 of the back-up block 66. It is appreciated that 
both the magnitude of the compression surface 68 on the back-up block 66 
and the location of the impact point 94 on the compression surface 68 vary 
depending upon the location of the back-up 66 with respect to the casing 
12. 
Constriction of the resilient tube between the tip 59 of the dispensing 
block 58 and the impact point 94 on the compression surface 68 of the 
back-up block 66 entraps a predetermined volume 95 of viscous liquid 
downstream of the constriction within the resilient tube 42. As seen in 
FIG. 5, continued application of the actuating force in the direction 
indicated by arrow 92 causes the yieldable extending arm 54 to deform in 
response thereto and generate a "rocking" action about the constriction 
point to bring the dispensing surface 60 of the dispensing block 58 into 
contact with a predetermined portion of the exterior of the resilient tube 
42. Continued application of the actuating force thereby causes 
compressive contact to be generated on the exterior of the resilient tube 
42 downstream of the impact point 94 between a portion of the dispensing 
surface 60 on the dispensing block 58 on one side of the tube 42 and a 
predetermined portion of the compression surface 68 provided on the 
back-up block 66 on the opposite side of the tube 42. The portion of the 
compression surface 68 in contact with the tube 42 is, of course, 
controlled by the location of the back-up block 66 within the casing 12. 
It may be appreciated that the magnitude of the overlap of the surfaces 60 
and 68 between which the exterior of the resilient tube 42 is compressed 
is functionally related to, and regulates, the magnitude of compressive 
force imposed upon the entrapped viscous liquid 95 within the resilient 
tube 42 downstream of the constriction. 
As seen in FIG. 5, imposition of a compressive force on the entrapped 
viscous liquid overcomes the spring bias imposed on the ball element 86 to 
move the ball element from its seated position about the inlet orifice 78 
and to permit viscous liquid to flow therethrough. The viscous liquid 
flows into the holding space 84 and through the outlet orifice 80, as 
indicated by the arrow 96, to expel a predetermined, measured, volume of 
viscous liquid from the resilient tube 42. 
Referring to FIG. 6, cessation of the actuating force on the yieldable 
extending arm 54 permits the arm 54 to rock back and return to its normal, 
non-deformed position, as indicated by the arrow 97, and to cease the 
generation of the compressive force on the viscous liquid within the 
resilient tube 42. Therefore, the force of the spring bias 88 becomes 
dominant and forcefully throws the ball element 86 against its seat about 
the inlet orifice 78. Further, as the resilient tube 42 assumes its 
non-deformed state, the lever arrangement 52 is further impelled to its 
initial position (FIG. 2). 
It may be appreciated by those skilled in the art that the rapid return of 
the ball element 86 to its seat adjacent the inlet orifice 78 within the 
valve housing 76 generates a suction force which draws any viscous liquid 
that remains within the outlet orifice 80 or immediately adjacent the 
exterior thereof into the distended volume 84 disposed within the valve 
housing 76, as indicated by the arrow 98. Therefore, unsightly and 
unsanitary coagulation and accumulation of viscous liquid about the 
exterior of the dispensing valve, which usually plagues prior art 
dispensing devices, is effectively prohibited by a dispensing device 
embodying teachings of this invention. It may further be appreciated that 
the utilization of a yieldable material to fabricate the extending arm 54 
replaces and overcomes the need for any mechanical biasing elements to 
return the actuating arm to its initial position. 
It may also be appreciated that an apparatus embodying the teachings of 
this invention provides an adjustable control for regulating the magnitude 
and volume of viscous liquid expelled from the resilient tube 42. By 
orienting and displacing the back-up block 66 with respect to the front 
cover 16, the location of the impact point 94 and the magnitude of the 
compression surface 68 on the back-up block 66 is varied. Thus, when the 
compression surface 68 on the back-up block 66 cooperates with the 
dispensing surface 60 on the dispensing block 58 to firstly constrict the 
tube 42 and secondly to impose a compressive force on the entrapped 
viscous liquid therein, the magnitude of the force imposed upon the 
entrapped viscous liquid is functionally dependent upon the magnitudes of 
the cooperating surfaces. Therefore, by varying the location of the 
back-up block 66 within the casing 12, more or less compressive force is 
imposed upon entrapped viscous liquid and accordingly, a greater or lesser 
volume of viscous liquid is expelled through the ball-check valve 48. It 
is also appreciated by those skilled in this art that a viscous liquid 
dispensing device embodying the teachings of this invention is operable to 
prevent unsightly dripping and coagulation of viscous liquid through the 
means suction force generated by the long-throw ball-check valve as that 
valve reseats itself at the termination of a dispensing stroke.