(1) Field of the Invention
The invention relates to an apparatus for automatically placing large plastic lids atop pail receptacles and a method for placing large plastic lids atop pail receptacles.
(2) Description of the Prior Art
Despensing and capping devices for a variety of containers are well known. For example, the milk industry has long utilized such devices for affixing bottle caps to bottles by equipment which dispenses one lid at a time and then affixes the lid over the bottle opening. Other areas of the food industry similarly have become proficient in capping a wide array of containers for perishable commodities. Different industries, such as the paint industry, have also developed methods for affixing lids to metal cans for paint, adhesives, petroleum products, joint compounds, and various materials.
In general, the lidding of conainers utilizes a magazine storage with means for advancing selective numbers of lids. Many forms of advancement are extant, and vertical, inclined, and horizonal magazine sections are utilized. Generally, however, such dispensing and capping equipment envisions smaller type lids such as those for necked-down bottles, medicine vials, wide-mouth jars for comestible contents, metal pails for petroleum and paint products, and various other typically circular containers. The food vending machine industry has solved problems of dispensing individually pre-packaged goods but has not had to deal with capping large receptacles. With the use of lids less than about six to eight inches in diameter, problems with non-uniformity and deformation are not encountered since the size tolerances and behavior of the material used is less variable. When large size receptacles, such as multiple-gallon pails, are lidded, magazine dispensation becomes difficult and the capping or placing onto the receptacle is manually performed.
Particularly large receptacles generally are covered with metal, or high density plastic, lids. One example of large metal lids would be in sealing large containers of asphalt emulsion, or tar, used in paving, roofing, and other construction-type industries. The inventor has particular concern for the utilization of high density plastic lids, specifically high density polyethylene. The prior art does not disclose a sufficiently adequate method or apparatus for both dispensing and placing such types of circular lids. A characteristic of high density polyethylene is that it tends to bow up in hot weather, which hinders automatic lidding operations. Additionally, the polyethylene type lid has been found to be supplied in non-uniform diameters, irregular rim sealing lips, and non-unifrom skirt lip dimensions. Such vagaries of dimension hamper lidding operations and implementation of an automatic method and apparatus for lidding large pail-type receptacles.
It has been discovered that additional problems relate to the sequence of filling and registering pail-type containers for subsequent lidding. This is problematic in that the spacing for larger containers, such as five gallon pails, may become random after proceeding along conventional conveyor belts, or the like, rather than neatly organized space-apart intervals as could be attained for example with small jars or cans. The problem is compounded when attempting to sequentially dispense one large lid at a time for affixation to the upper rims of the pails. The two steps of filling and lidding are desirably coordinated so that continuous operation is afforded.
(3) Objects of the Invention
It is accordingly a primary goal of this invention to provide a method and apparatus for automatically dispensing and lidding large pail-type receptacles with large diameter plastic lids.
It is moreover a critical object of the invention to provide such automatic placing when non-uniform plastic lids are used.
It is an allied goal of the invention to lid pail-type receptacles, having upper circular rim portions, with high density polyethylene lids having a peripheral skirt or lip portion.
It is an important goal of this invention to provide a method and apparatus which allows for dispensing and lidding pail-type receptacles one at a time wherein filled pail containers may be advanced after a filling operation through a lid placing operation without regard to spacing and without sacrificing a continuous operation.