CA2947538A1 - Battery protection pouch, herein referred to as "bpp kit" - Google Patents

Description

Subject of matter of the invention:
The invention consists of a protective application for cordless power tools.
It employs a flexible outer cover as a means to shield the device from the elements, as well as preventing accidental ejection of the battery pack during use. A retractable safety strap is incorporated into the protective sheath (or tool handle) to help mitigate accidents caused by the operator losing control of the power tool.
Here called:
Battery Protection Pouch, herein referred to as "BPP kit".
Scope of Invention:
The invention generally relates to cordless power tool applications, in particular those employing a removable battery-pack housing for its operation.
Background of the invention:
The purpose of developing such a device was realized through personal work-site experience, where many such tools are commonly utilized. Construction environments are uniquely challenging in that they scarcely provide the luxury of immediate access to existing formalized power grids. The flexibility of using portable power tools comes at the expense of a limited power supply.
Additional difficulties include harsh work environments, where exposure to the elements can significantly impact work progress and efficiency. Battery efficiency suffers significantly in conditions of extreme hot or cold and moisture.
Work-site injuries caused by fallout are common, costly and largely avoidable.
The vast majority of power tools manufactured today are constructed from plastics, which over time can weaken from the friction of frequent engagement and disengagement of the battery housing from the unit. Replaceable battery packs need to be secured against accidental disengagement from the mechanical part of a cordless tool assembly. Additionally, the incorporation of a safety strap can significantly reduce the chance of injury to others and damage to the operating unit and its battery pack.
Introduction:
The primary function and design of this invention is to improve work safety and to augment the efficiency of battery cells by providing a necessary moisture barrier to protect against an extreme range of environmental and climatic elements. The battery housing itself, traditionally constructed from a rugged synthetic material, offers only basic shelter to the battery cell assembly. Past inventions concentrated their efforts on inner parts, mainly electronic improvements and more efficient venting.

The combined battery weathering pouch (BPP device) serves following role:
1) Protecting the battery pack from accidental disengagement from the mechanical portion of the tool (i.e. fall out causing lethal harm to bystanders).

2) To protect the battery pack (cells) from out of tolerance low-temperature operating conditions.
This is of particular importance in high elevation construction applications because of the harsh working environment. Examples include: shipyards, high-rise buildings, communication masts or towers, power line maintenance, general outdoor works etc.

3) Winter or off season battery storage; where its use may vary from industrial to residential applications.

4) Environmental benefits include: decreased recycling and disposal time, and extending the operating time and life span of battery cells.
The present invention provides a method to prolong battery cell life span and duration, while at same time combining practical remedies in overall safety enhancement for the user and bystanders.
Other aspects associated with this invention pertain to the end user and the proprietary battery (pack) manufacturer. In most cases the manufacturer warranty limits the use of battery packs to ambient room temperature. More frequent recharging depletes the battery cell lifespan, and thus efficiency.
With the implementation of this invention, both the end user and the battery pack manufacturer become beneficiaries. The BPP kit serves as a marked improvement in the standard of safety regarding the application of cordless power tools. In work site scenarios, a battery pack may accidentally disengage from the mechanical portion of the tool for a number of reasons: the battery was improperly installed, the guide tracks or clips have become worn or damaged, significant vibration (impact drill), angle and grip of device by the user in conjunction with the previously mentioned factors.
The free-fall of a battery pack from a high elevation, regardless of its actual size or weight can cause serious injury or death. Accidental damage to a battery pack is not covered under standard warranty policies. In most cases the manufacturer's limited warranty applies to typical but not extreme working conditions.
Safety issue:
Presented invention decreases overall chance of accidental disengaging of a battery pack (sliding off) caused perhaps by not intentional movement of a tool operator or due to its prolonged use. Wear and tear of its guiding trucks, connecting channels becomes more imminent, as plastic material wears faster compare to all metal made parts and recharging cycles must be increased as the battery becomes weak.
Overall combination of poor workmanship, poor maintenance habits and poor workers safety training becomes an immediate threat of harm, which varies depending on the context in which the cordless tool is implemented but not limited to an extreme condition of work place, confined spaces or high elevation works type and on.
Based on the aforementioned, the invention strives to make improvements to protect the battery pack, its electronic parts in conjunction with the cordless tool housing, the user and possible bystanders. This is achieved through the very simple and economical design of the BPP.

The invention provides flexible insulation and shock-buffering protection for the battery pack;
effectively eliminating the potential for dangerous projectiles of debris should the unit be dropped from a significant height onto a hard surface. The battery protection pouch will contain any shattered pieces from being launched outward from the point of impact.
The following illustrations demonstrate common worksite situations where extra caution must be exercised in regard to safety:
Figure 1 - Typical safety technique implemented on work sites. A single strap secures a cordless impact drill from its handle.
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The same cordless drill secured with a safety strap, but implementing the BPP
kit - securing against accidental disengagement of the 36V battery pack.
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Larger capacity battery packs such as those of the 24 volt and 36 volt configuration weigh significantly more than a standard cordless drill battery pack and are at a greater risk of accidental disengagement due to the greater stress on the locking point. A cordless battery pack may disengage from the operating mechanical tool for a variety of reasons such as, but not limited to:
vibration, angle of operation and loss of control due to human error.
In Canada alone, construction safety rules prescribes working remedies to a given work scenario, here said: must use a safety strap fall arrest while operating a cordless tool on higher elevation more than 10 feet. This safety rule is written in conjunction of a standard fall arrest system implemented by an individual workman, regardless if operating on a concrete surface, scaffold or lifting platform.
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1 , The BPP addresses these issues and adds a preventative level of safety to cordless tool applications.
The Velcro straps implemented into the BPP device serve as a safety feature in order to hold the battery pack firmly in place, preventing its accidental disengagement.
It is a common occurrence on work sites for a battery pack to disengage and drop from the mechanical unit due to vibration or weakened guide tracks or clipping brackets.

Figure 3 ¨ A compact cordless impact tool, secured with a fall-arrest strap and the BPP kit.
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Distinct features and innovations No previous constructions of a cordless battery pack outer shell assembly to date have addressed safety, performance and efficiency the way the BPP does. In general, battery cells are protected by a custom fitted plastic composite material. The container (battery case) is vented through vent holes to allow the gases that form within the cells to escape.
The presented invention serves a dual purpose. First, to secure the removable battery pack to the mechanical assembly of the tool, and secondly to utilize the flow of hot air being vented out by the electric motor during its operation to aid the battery pack in maintaining an optimal operating temperature range. In simple terms, heat generated inside the tool (body of the tool; the shell) from its operation that would otherwise be channeled out and away from the unit is instead captured and used to buffer battery cell temperature.
By withholding and recycling even a small amount of hot airflow the BPP
invention improves the overall productivity of a cordless tool battery pack (particularly in conditions of extreme cold). This feature has not been seen or implemented in past inventions by cordless tool manufacturers.

References of relevant patent applications that pertain to "battery cooling systems"
This problem has been mentioned and addressed in US Patent nr 7733054 B2 classified under Thermal Management Systems for Battery Pack. In regards to its early publication: US
Patent 20030027037A1 the problem of venting (out) batteries is described as following:
õ the present invention relates to battery cooling systems and, more specifically, to systems for cooling batteries for cordless power tools". In addition Section 0004 of that application states the following:
"...the heat created during discharge of the batteries as well as charging of the batteries which, in turn, leads to increased temperatures, may have a severe effect on the life expectancy and performance of the batteries. In order for batteries to properly charge, the batteries must be below a desired threshold temperature and the differential temperature between the cells in the battery pack should be minimized.
Likewise, if the batteries become too hot during use, battery life will be cut short. Also, if a battery is below a certain threshold temperature, it will be too cold to charge and must be warmed before charging. Thus, it is desirous to maintain batteries within a desired temperature range for optimum performance as well as optimum charging."
That is a fair and true statement.
However technical abbreviation of Thermal Management has other meaning:
conserving the energy.
Thermal Management by definition is implicit in the conservation of energy. In this particular application, this can be achieved by redirecting and reusing the hot air and gases generated by a cordless power tool's electric motor and its battery cells to maximize operating temperature efficiency.
In this way the BPP kit invention enhances energy conservation.
New features compared to some previously registered invention (a specific reference made):
It is well established that NiCad type batteries contain toxic metals, and a common problem when heated (eg. recharging battery cells) is that gases generated must be vented out to prevent possible pressure buildup inside the battery pack housing.
Therefore, specially designed venting holes are implemented (US patent reference Nr. 7733054) to eliminate or minimize such scenarios (volatile gas buildup).
The BPP device has been designed and constructed to withhold an excess of heat generated within a certain area of the cordless tool to keep the battery pack warm as long as possible and to prevent its rapid discharge to the outside environment. To elaborate, the design of this invention allows for the discharging gases generated by the unit to circulate freely around the battery casing, and finally escaping (at a much slower rate) without risk of causing an explosion or fire because the BPP device is not an air-tight constructed apparatus.

Additional considerations:
The venting ports mentioned as per patent registry references: 7733054 -20030027037A1 here state that by creating a direct airflow and allowing the discharge of heated gases to escape the cordless tool casing assembly and further throughout battery housing enables a cooling action.
This is truly beneficial in summertime use, or in dry shop or factory environments. However, it has been established that the same venting holes have a negative benefit in cold, damp climates where rainfall and snowfall are typical. The exhaust or venting ports allowing heated gases to be discharged from the battery inner housing have one major disadvantage:
Through these constructed vents, moisture or condensation may penetrate the battery pack cells causing premature damage. If a cordless tool has been steadily exposed to rain or snow, these venting outlets can allow moisture to penetrate inside the battery housing, consequently causing irreversible damage to the cells, thus shortening the expected battery life span.
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Solution to the matter:
Without additional weathering protection and an effective moisture barrier, battery cells will prematurely be exposed to corrosion. Consequently, the battery pack may become unstable, and impossible to be fully charged due to the reduced integrity of the battery cells and its contact points. It is well known fact, that moisture buildup inside battery inner box will cause harmful reactions between the electrodes. The BPP remedies these issues and more in a simple cost-effective manner.
Optimum operational use and the temperature factor (science and technology explanation):
Foreword:
It is not the inventor's position to compare, discuss or criticize a given type of battery cell or its possible advantage or disadvantage with regards to general cordless power tools and their performance.
Regardless of the battery pack utilized (NiCad or NiMH or Li-ION) there is no intention stated or otherwise implied by the inventor to endorse the comparative advantages or limitations of a particular battery technology. No matter how sophisticated a battery pack can be constructed, the fact remains:
The temperature level is a major factor in the longevity and overall performance of a battery cell pack.
Most batteries (portable, liquid or solid) are designed to operate optimally between 10 C and 35 C, just like the human body. Beyond these operating parameters, performance tends to be reduced. The performance of most batteries (vehicles, cell-phone etc..) suffers at very low temperatures, while there is the possibility of freezing (condensing, shrinkage) of the electrolyte and the overall chemical reaction is slowed. To explain this reaction the inventor makes reference to the Arrhenius equation formula - for the temperature dependence of reaction rates.
The equation was proposed by Svante Arrhenius in late 19th century and showed that for every increase of 10 C in temperature, the chemical reaction rate doubles.
Basic chemistry suggests that the higher the temperature, the faster a given chemical reaction will proceed. The active ingredients of the battery cells are therefore typically engineered to allow the maximum operating temperature range under normal dry temperatures.
Battery operating temperature (and by extension, storage temperature) has a major impact on the service provision, life-span and overall operational reliability.
A simplified working example may be given on this subject:
Frustrating and stressful situations may be avoided such as attempting to change a battery pack while working at a high elevation (eg. a transmitting tower, or an offshore windmill turbine installation).
Not having to change the battery of a cordless power tool due to premature discharging can make a significant difference in task proficiency from a time saving standpoint.

Other benefits listed:
The BPP kit helps to preserve the engraved information (serial number and battery information) that relates to the manufacturer's claimed warranty, which often vanishes from the bottom side of the battery due to extensive contact with cement flooring or common dirt and debris accumulated on its surface. The BPP kit may also be implemented as an off work season battery protection storage method. Demand for energy conservation has been gaining momentum for years and the BPP kit is an affordable and effective solution for industrial and domestic applications.
The BPP device presents a desirable, long-lasting performance enhancement for cordless tool battery applications.
Summary of the invention:
The BPP device claims:
To maximize battery cell efficiency through a slower discharge rate under low temperature operating conditions, and to firmly secure the battery pack housing against the mechanical part of a cordless tool as a means of preventing its accidental fall out or disengagement.
The independent advantages of the invention as outlined in the above documentation is a combination of thermal protection packing and the implementation of unobtrusive safety features, all in one compact, cost-effective application.
Brief description of the attached drawings and practical illustration (Fig.
land Fig. 2) Please note the disclosure and descriptions here are intended to be illustrative and informative as per all essential characteristics of the BPP device. In some instances, well known raw material such us Kevlar, Gore-Tex, Velcro straps or thermal silicone, reflecting aluminum padding etc.-used to construct the BPP device have not been specifically shown or described in detail to avoid unnecessary confusion relating to the overall size of s cordless battery, its shape , voltage capacity, gross weight etc.
The invention may take on many specific forms, shapes and may be constructed from a variety of material suited for its specific task or climate zone application.