Abstract:
A dispenser for viscous materials such as toothpaste is disclosed. The dispenser comprises an elongated container having a spout at its upper end and a rockable finger actuator operable to dispense contents when depressed. The actuator is connected to an elongated operating rod which is coupled to a follower by means of a spray clutch which causes the follower to move upwardly in the container in increments in response to rocking motion of the actuator. The lower end of the operating rod is connected to a base member having a resilient portion and a peripheral recess which receives the lower end of the container. The resilient portion of the base member pulls the operating rod downwardly for repositioning the same after each stroke of the actuator, and the operating rod pulls upwardly on the base member to securely mount the same to the container.

Description:
FIELD OF THE INVENTION 
     The present invention relates to dispensers for viscous materials, and more particularly, the present invention relates to a viscous material dispenser of the type having a container in which a follower is displaced axially toward a spout by an operating rod connected to an actuator. 
     BACKGROUND OF THE INVENTION 
     Various types of viscous material dispensers are known. Examples of such dispensers may be found in the following U.S. Pat. Nos.: 949,545; 1,212,010; 1,244,324; 1,668,511; 1,921,912; 2,151,684; 2,243,774; 2,557,952; 2,604,858; 2,732,101; 3,088,636; 3,215,320; 3,255,935; 3,361,305; 3,768,705; 4,154,371; 4,301,948; 4,413,759; 4,421,255; 4,437,584; 4,437,591; and 4,461,403. While the patented dispensers may function satisfactorily for their intended purposes, there is a need for a viscous material dispenser which is reliable in operation, which has a minimum of parts, and which is inexpensive to manufacture. 
     OBJECTS OF THE INVENTION 
     With the foregoing in mind, a primary object of the present invention is to provide a novel viscous material dispenser which overcomes the limitations of known viscous material dispensers. 
     Another object of the present invention is to provide an improved viscous material dispenser which is reliable in operation. 
     A further object of the present invention is to provide a unique viscous material dispenser which can be manufactured and filled economically utilizing a high-speed mass production equipment. 
     SUMMARY OF THE INVENTION 
     More specifically, the present invention provides an improved dispenser which is particularly suited for use in dispensing viscous materials, such as toothpaste. The dispenser comprises an elongated container having an upper end with a spout and a finger-actuated rocker arm actuator. An elongated operating rod is connected at its upper end to the actuator and depends therefrom axially inside the container where it is connected by a sprag clutch assembly to a follower. Rocking motion of the actuator causes the operating rod to reciprocate for advancing the follower upwardly in the container for dispensing contents from the spout. A base member has a resilient portion extending across the lower end of the container and engaging the lower end of the operating rod for biasing the same downwardly to reposition it relative to the follower after each dispensing stroke. A recess in the base member receives the lower end of the container and cooperates with the operating rod to securely mount the base member to the container. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, features and advantages of the present invention should become apparent from the following description when taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a longitudinal sectional view of a viscous material dispenser embodying the present invention; 
     FIG. 2 is a sectional view taken on line 2--2 of FIG. 1; 
     FIG. 3 is a sectional view taken on line 3--3 of FIG. 1; and 
     FIG. 4 is a sectional view taken on line 4--4 of FIG. 1. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, FIG. 1 illustrates a dispenser 10 which embodies the present invention. The dispenser 10 is particularly suited for use in dispensing viscous materials such as toothpaste, shampoo, grease, etc. Accordingly, while reference hereinafter will be made to toothpaste, it should be understood that the dispenser of the present invention can be used to dispense a variety of products. 
     As best seen in FIG. 1, the dispenser 10 comprises an elongated tubular container 1 having an upper end 11a with a transverse end wall 12 and a lower end 11b. The lower end 11b terminates in a circular edge defining an opening through which the container 11 is filled when inverted. A dispensing spout 13 is formed integral with the upper end wall 12 of the container 11 and projects upwardly therefrom to one side of its longitudinal axis. An annular rib 15 on the end wall 12 cooperates with a complementary rib 16 on a cap 14 to hold the cap 14 in place on top of the container 11 in the manner illustrated in FIG. 1. 
     The container 11 is adapted to contain toothpaste T and to dispense the same from the spout 13 after the cap 14 has been removed. To this end, a follower 17 is mounted in the container 11 for movement axially therein to pressurize the toothpaste T. The follower 17 has a peripheral skirt 17a which engages the inner periphery of the container 11. The skirt 17a slidably engages the inside of the container 11 in a fluid tight manner to prevent the contents thereof from leaking. 
     The follower 17 is displaced upwardly in the container 11 by means of an operating rod 18. As best seen in FIG. 1, the operating rod 18 extends axially inside the container 11 for substantially its entire length. The operating rod 18 has a lower end 18a located adjacent to the bottom of the container 11, an upper end 18b located adjacent to the top of the container 11, and a series of annular ribs 18c spaced apart in increments along substantially its entire length. 
     The operating rod 18 is connected to the follower 17 by means which causes the follower 17 to move unidirectionally upward when the rod 18 is displaced upwardly. To this end, a metal-stamped sprag clutch assembly 19 having a series of flexible fingers 19a, 19b engages the operating rod 18 between the ribs 18c as shown in FIGS. 1 and 3 to grip the rod 18 in a downward direction so that when the rod 18 moves upwardly, it causes the follower to move upwardly with it. The sprag clutch assembly 19 permits the rod 18 to move downwardly relative to the follower 17 in a well known manner. 
     To displace the operating rod 18 upwardly, the upper end 18b of the operating rod 18 is connected by means of a flexible strap, or hinge, 20 to a rocker arm finger actuator 21 mounted in a trunnion 22 formed on the end wall 12 of the container 11. The strap 20 is molded integral with the rod 18 and the finger actuator 21 of the same plastic material. Pivotal movement, or depression, of the finger actuator 21 clockwise in the direction indicated by the arrow in FIG. 1 causes the operating rod 18 to move upwardly in the container 11, and this advances the follower 17 upwardly and applies pressure to the toothpaste T for causing it to flow out the spout 13. 
     A prior art dispenser of the type just described is disclosed in U.S. Pat. No. 4,437,591, the disclosure of which is incorporated by reference herein. In the patented dispenser, a spring element is provided for pivoting the finger actuator in the counterclockwise direction for urging the operating rod downwardly relative to the follower at the completion of a dispensing stroke to reposition the rod with respect to the follower and to ready the same for the next dispensing stroke. In this dispenser, the spring element is formed integral with the finger actuator and engages the upper end wall of the container for effecting the desired counterclockwise pivotal movement of the finger actuator. With this container, however, it has been necessary for the hinge to be fabricated of a special plastic material capable of sustaining the alternate tension and compression loads on the operating rod. While the operating rod itself can be fabricated of a low cost plastic, it has been necessary to fabricate the plastic material of the hinge of a more expensive grade of plastic, and this necessitates a more complex molding operation. Furthermore, in such containers, the hinge has been a source of failure of the product because of the repeated stressing of the hinge axially in opposite directions while undergoing flexure. 
     The present invention overcomes the aforementioned limitations of a known prior art container of the type described and provides a dispenser which is durable and yet which can be manufactured economically. To this end, a means is provided for maintaining downward tension on the operating rod so that the hinge is maintained in tension at all times. This is accomplished in the present invention by providing a base member 25 which functions both as a container base and as an operating rod biasing means. 
     To this end, and as best seen in FIG. 1, the base member 25 has a resilient wall portion 26 extending transversely across the lower end 11b of the container 11 and a peripheral recess 27 which receives and engages the lower end 11b of the container 11. The base member 25 has an outwardly extending and downwardly depending flared portion 28 with a lower edge 28&#39; adapted to engage a support surface to support the container 11 upright. Preferably, the flared portion 28 has one or more straight sides 28a, 28b (FIGS. 2 and 4) to prevent the container 11 from rolling when laid on its side. 
     The base member 25 operatively engages the operating rod 18. For this purpose, the resilient wall portion 26 of the base member 25 has a central aperture 26a through which the lower end 18a of the operating rod 18 depends. The lower end 18a of the operating rod has an integral barbed head 18c having an annular shoulder 18&#39;  which engages the underside of the resilient wall portion 26 of the base member 25, and the head 18c is tapered in the manner illustrated. Thus, the base member 25 can be mounted on the lower end 11b of the container 11 and connected to the operating rod 18 simply by pushing the base member 25 axially with respect to the container 11 until the operating rod head 18c passes through the aperture 26a and the shoulder 18&#39; engages the underside of the resilient wall 26. 
     The base member 25 positively biases the operating rod 18 downwardly. To this end, the resilient wall 26 has a concave, or dished, configuration, such as illustrated, and it deflects upwardly in response to upward movement of the operating rod 18 when the finger actuator 21 is pivoted clockwise in the direction indicated by the arrow. 
     In the illustrated embodiment, a stop surface 22a is provided adjacent to the spout 13 for engaging the finger actuator 21 to limit its pivotal movement in the counterclockwise direction. Thus, the stop 22a and trunnion 22 cooperate with the resilient wall portion 26 of the base member 25 to maintain tension on the operating rod 18 and its strap 20. 
     The cap 14 aids in the assembly of the dispenser 10 by stabilizing the position of the operating rod 18. To this end, the inside of the cap 14 is provided with a series of centrally located gussets 14a, 14b which depend from its end wall 14c and engage the topside of the finger actuator 21 in alignment with the strap 20 and operating rod 18 when the cap 14 is mounted on the container 11. The cap 14, and its gussets 14a, 14b, prevent the operating rod 18 from moving axially in the container 11 when the follower 17 is engaged with the operating rod 18 and the base member 25 is assembled onto the lower end 11b of the container 11 after the container 11 has been filled with toothpaste T. After engagement of the operating rod 18 and base wall 26 in the manner illustrated, the flexible wall portion 26 of the base member 25 applies a slight amount of tension to the operating rod 18, and thereby to the strap 20, for causing the finger actuator 21 to normally assume the home, or inactive, position illustrated in FIG. 1. 
     In use, the gap 14 is removed from the container 11 and the dispensing spout 13 positioned in dispensing relation with respect to the bristles of a toothbrush. A person then engages a thumb or finger with the finger actuator 21 and pivots the same clockwise in the direction of the arrow in FIG. 1. As the actuator 21 moves clockwise, it pulls upwardly on the strap 20 while flexing the same, and the strap 20, in turn, pulls upwardly on the operating rod 18. By virtue of the sprag clutch assembly 19 interconnecting the follower 17 with the operating rod 18, the follower 17 is pulled upwardly in the container 11 along with the operating rod 18. 
     As the follower 17 moves upwardly, it pressurizes the toothpaste T in the container 11, and this causes the toothpaste to flow out the spout 13. At the same time, the resilient flexible wall 26 of the base member 25 flexes upwardly by virtue of its interconnection with the lower end 18a of the operating rod 18 and the bottom of the container 11 continuing to maintain tension on the operating rod 18. When pressure is released from the finger actuator 21, however, the resilient wall 26 flexes downwardly toward the position illustrated in FIG. 1, enabling the sprag clutch 19 to permit the operating rod 18 to move downwardly with respect to the follower 17. The resilient wall 26 continues to pull the operating rod 18 downwardly until the finger actuator 21 engages its stop 22a. Thus, the finger actuator 21 is returned to its home position, and the follower 17 is reengaged with the operating rod 19 at a higher position to ready the dispenser 10 for the next dispensing stroke. 
     The container 10 may be stored upright in the manner illustrated in FIG. 1, or it may be laid down on its side without rolling as a result of the flat surfaces provided on the base member 25. 
     The aforedescribed structure has a number of advantages. First of all, the resilient wall portion 26 of the base member 25 exerts a relatively strong pull on the operating rod 18 to insure that it maintains the operating rod 18 under tension and causes it to reengage the follower at new location to be ready for the next dispensing stroke. Since the strap 20 does not undergo compressive stresses in use, it is fatigue resistant and therefore resistant to failure. Thus, the operating rod 18 and its strap 20, can be molded of the same low cost plastic in a straightforward molding procedure. The novel base member 25 provides, not only a means for biasing the operating rod 18 downwardly, but also a closure for the lower end of the container to prevent foreign matter from entering the same. Furthermore, the design of the base member 20 is such as to be capable of being molded in one piece and assembled readily with the container 11 simply by pushing the same together. Accordingly, the dispenser 10 of the present invention is not only economical to manufacture, but it is also durable and reliable in use. 
     While a preferred embodiment of the present invention has been described in detail, various modifications, alterations and changes may be made without departing from the spirit and scope of the present invention as defined in the appended claims.