1. Field of the Invention
The present invention relates generally to container cap removers, and particularly to a gripper device which is formed of a generally solid body of rubber-like resilient material and has one or more recesses for snuggly fitting container caps within given size ranges.
2. Description of the Known Art
Hand held devices for removing twist off screw caps from containers are known generally. Some of the known devices are formed so as to engage the outer periphery of a container cap at discrete point locations with a corresponding number of blades or metal edges which are contained within a hard plastics shell. An example of such cap opening device is disclosed in U.S Pat. No. 3,730,025 issued May 1, 1973. The device of the '025 patent comprises a disc-shaped plastics shell having a conical socket, and typically four metal blades having edges which are stepped and project slightly from the wall of the recess at evenly spaced locations on the periphery of the recess wall. In order to remove a tightly closed bottle cap, the user places the shell of the device down over the cap so as to cause each of the blades to engage the cap firmly at a certain step, and then twists the shell while holding the bottle with the other hand.
It will be appreciated that since the device engages the bottle cap at only four individual point locations on the cap periphery, and only those cap sizes which correspond to the steps formed on the blades can be opened with the device, it has certain disadvantages. First, since a substantial force is imparted from each of the blades to the bottle cap at the points of engagement, gouging of the cap is bound to occur. Such result may not be desirable in cases where the contents of a container are not consumed all at one time and the container is ordinarily openly displayed, e.g., medicine containers, spice jars, perfume bottles and the like.
Second, if a cap to be opened does not fit snuggly in the blade steps due to the size or shape of the cap, the device becomes virtually unusable and the blades may even be damaged if the user exerts enough force while trying to open a cap which is improperly seated in the blades.
A cap gripping device is also known from U.S. Pat. No. 3,604,290 issued Sept. 14, 1971. The device of the '290 patent also includes a body member of rigid plastics material in a frustoconical shape. A correspondingly shaped recess in the shell is lined with a gripping member of resilient material the inner surface of which is slotted by a series of tapered grooves. The device is used substantially in the same way as the gripper of the '025 patent described above, and also requires the exertion of some downward force to maintain frictional engagement with a cap to be removed, while the user twists the device with one hand.
Other known screw cap removers are in the form of a sheet of resilient material such as vinyl rubber, and operate merely by allowing a part of the sheet to be wrapped about the periphery of the cap while the user holds the sheet and attempts to twist the cap through frictional engagement between the sheet and the cap. Two examples of such cap removers are disclosed in U.S. Pat. Nos. 4,090,419 issued May 23, 1978, and U.S. Pat. No. 2,880,633 issued Apr. 7, 1959.
A vinyl sheet rubber jar and cap remover is also disclosed in U.S. Pat. No. 2,985,044 issued May 23, 1961. The cap remover of the '044 patent comprises a number of superimposed concentric circular ring-like portions of various diameters, each ring portion presenting a vertical inner face wall. In use, a container cap having a diameter which most closely approximates one of the concentric portions is received in that portion, and the corresponding inner face wall is pressed against the periphery of the cap when the user grips the exterior face of the selected circular portion and squeezes the wall of that portion against the cap while attempting to twist the cap off of the container. It will be appreciated, however, that the cap remover of the '044 patent has the disadvantage that it does not accommodate an infinite number of cap diameters within a given range, and the inner face wall of a non-accommodating ring-like portion will not firmly grip the periphery of an odd cap. Accordingly, when a twist force is exerted by the user under such loose-fit condition, the selected portion deforms from its preformed circular shape so that much of the cap periphery is not subjected to any rotational or twisting force while the user grips the exterior face of the selected portion. Further, even if the diameter of one of the ring-like portions was such as to provide a close fit on a container cap, the user would have to apply substantially the same force to the exterior face of the portion to remove the cap as would be required if the user attempted to remove the cap directly by hand. Such result follows since the walls of the ring-like portions are relatively thin, viz.,about 1/8 inch.
Until now, there has not been known a gripper device for container caps which device can accommodate effectively a large variety of caps having various sizes and shapes while affording the user at least some mechanical advantage during a cap removal operation. Further, there has not been known a container cap remover which requires only a minimum degree of manual exertion when used to remove extremely tight container caps and particularly small-sized odd shaped caps such as used on tubes containing glue.