Prior art power packs for video equipment comprise a variety of lead acid batteries. The power provided by these power' packs are directly proportional to the size and weight of the power packs. Power packs having sufficient constant power output to operate a video camera for a reasonable length of time are burdensomely heavy. Even with the additional weight and size, these power packs do not satisfy the needs of most amateur and professional video enthusiasts.
A major problem for video equipment manufacturers is the packaging of the power packs. Prior art assemblies include a great amount of wasted space and further, there is a great concern among manufacturers that the packaging of the power packs should withstand the stresses encountered during use. Video power assemblies must be able to withstand a great deal of abuse during use.
This invention provides a power cell casing or packaging assembly which is compact yet provides structural support for a plurality of power cells contained therein. Unlike prior art shrink wrapped assemblies wherein a plastic casing is shrink wrapped around a plurality of power cells, this invention provides rigid internal support which shields the power cells from the external environment.
Power pack assemblies including rechargeable cells, such as nickel cadmium cells, have been found to provide greater power consistently over a significantly longer time span as compared to prior lead acid cell assemblies. The rechargeable cells are therefore quite economical. Optimally, naked nickel cadmium cells having an exposed charged pole and like charged cylindrical portion and an oppositely charged second pole are used. The use of such naked nickel cadmium cells present several problems. The cells are connected electrically in series. It would be quite awkward to have a single row or a stack of D size nickel cadmium cells, especially when power cell packs may require ten D size nickel cadmium cells. Hence, the cells must be arranged in a series of stacks having optimally two power cells in a stack and the charged cylindrical casings of adjacent stacks must be separated and insulated from each other. Secondly, the exposed oppositely charged poles of adjacent stacks must be electrically connected but the means connecting the cells, such as a conductive strip or wire, extending from a charged pole must be separated and insulated from the oppositely charged casing of the same cell, the casing usually extending over the charged pole and insulated from the pole internally. External insulation is required between the charged casing and the conductive connector. Thirdly, the charged naked cells must be insulated from the external environment while being encapsulated in a protected container. This invention provides a casing for insulating the naked nickel cadmium power cells internally and externally while further providing structural rigidity internally and protection from external abuse. Finally, this invention provides a novel process for manufacturing the power cell assembly wherein the power cells are lined and connected in series within the casing itself. In other words, the casing is an assembly tool in which the power cells are electrically connected.
USPTO Backgrounds
USPTO Backgrounds