Patent Application
20080185268
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This invention relates to electrical switches. More specifically it relates to lockable electrical switches. Even more specifically it relates to lockable electrical switches which can be installed into an existing product.
A number of patents have been filed for safety devices for power tools that can lock the power switch so that the power tool is rendered inoperable. Most of these involve a physical barrier to turning on the power tool, but generally do not involve an actual lock that can prevent the power tool from being operated without unlocking the lock.
The U.S. Pat. Nos. 4,166,202 and 4,389,550, both by Reiter, are examples of safety switches that do use a lock to prevent the operation of a power tool. Patent '202 describes a system that can lock a power switch using a key. Once locked, the power switch cannot turn on the power tool, but an emergency button can turn the power tool off if it is already on. Patent '550 also is a similar system that uses a key lock to prevent the operation of the power switch. Patent '550 also has an emergency button that can turn off the power tool even when the switch is locked. The '550 also can be placed in the cord of the power tool to prevent operation. In both patents, the key lock is integrated into the housing for the switch and the housing is required to have an emergency off button.
While the '202 and '550 are useful, they are limited by the complex parts of each switch and housing, by the required emergency off button, and by the specific integrated lock. Both patents require that the lock is a key lock that operates by rotating a cam out of the path of the power switch. In fact, in both patents, the lock only works if it can block the path of the switch. The lock does not actually secure the switch or the toggle for the switch.
The purpose of the invention is to create a universal means, a lockable electrical switch (hereafter called “the device” or “the invention”), that can be used in all cases by all people, for controlling the use of an electrical apparatus (hereafter called an “apparatus”) powered or activated by the standard two-phase or three-phase alternating current (A.C.) electric power source commonly used in homes, offices, factories, and elsewhere. The preferred embodiment is as a parental control device, but other applications as a security and safety device are possible.
Many sorts of switches exist to allow parents or others to control access to a computer, television, or any other electrical apparatus. Most of these switches are integrated into the functioning of the apparatus, and they generally limit access to some, but not all of its functions. Furthermore, they normally must be purchased with the apparatus, and older models do not have these features.
This invention allows one to control whether an electrical apparatus can be turned on or off. Rather than rely on complicated functions or controls, this invention creates a lockable switch that interrupts the flow of electric power from the wall receptacle to the apparatus.
The invention is simple to operate, so that parents and others will be able to control access to the apparatus without frustration. This avoids a problem with existing parental control devices: some are complex, and a child may better understand how to operate them than do the parents. Furthermore, the simplicity of the invention allows it to resist malfunction to a greater degree than more complicated devices.
The invention can be sold as a kit or unit that can be installed easily for an existing electrical apparatus, simply by insertion into the power cable. The invention can also be sold as a kit where a purchaser supplies his or her own lock that fits a specific need.
The essential application of the device is to provide a means to prevent unauthorized access to electrical equipment. Thus a computer can be secured by preventing any person without a key to the lock from using the computer. Alternatively, the invention could be used to prevent use of dangerous machinery, such as a saw powered by A.C. power from the wall, by allowing only a person with the key to the lock to use the apparatus. In this way the invention can also be a safety device.
This invention is an electrical switch that can be locked in either an “on” or an “off” position. The switch is attached to one of the wires within the main electrical power cord in such a manner that the switch can interrupt the circuit that the cord is part of.
A very simple form of the device is shown in
The device can be of any type that can allows a switch to be locked temporarily in an “off” or an “on” position. The one shown in the drawings involves a simple mechanical padlock or combination lock, in which a lock-bar can fit into the holes in the casing and toggle and fixed in place. The lock can also be an electrical lock, in which case it could be controlled remotely, by way of a keypad or radio, or by other electronic means. The switch could also be controlled by specific sound or ultrasound patterns, optical or ultraviolet or infrared energy, or analogous means.
The accompanying drawings, which are incorporated in and form part of the specification, illustrate the embodiments of the present invention and, together with the description, serve to explain the principles of the invention.
Electric energy is applied to the apparatus by means of a pair of power-conducting wire 14 and power-conducting wire 15. In putting the invention in place, one of the two power wires for two-phase feeding the apparatus 14 is cut in two, and each free end is then attached to its corresponding wire-fastener 12 or corresponding wire-fastener 13. The other power wire for the apparatus 15 passes through the device undisturbed.
The lock 8 can be a separate pad lock or combination lock or other lock with a lock bar that can pass through hole 6 and either hole 2 or hole 3; alternatively, it can be integrated into the device.
The switch itself consists of a toggle-contactor 4 and hinge 10, a contact 11, a non-conducting toggle-handle 1 with the hole 2 and hole 3 and a non-conducting, rigid connector 9, two wire-fasteners 12 and 13, and a non-conducting base-plate 18 to which the pieces are rigidly attached. In practice, the switch can be any standard electrical switch. The switch creates a drawbridge across the gap spanning the toggle-contactor 4 and the contact 11. The switch is in a closed position when the toggle-contactor/hinge connects the two and it allows electrical current to flow between them. The switch also has an open position, in which the toggle-contactor 4 does not touch its contact 11, which prevents electrical current from flowing between them.
The invention could be sold as a kit that could be installed into existing electrical circuit. The preferred embodiment envisions a kit that can be installed into a power cord of a common electrical apparatus. The kit would allow the user to separate the housing 5 from the base-plate 18 by means of several screws. The two wire-fasteners are attached to the base-plate 18 in such a manner that each fastener 12 or fastener 13 allows attachment of a wire. A preferred embodiment envisions the contacts as screws or clips. A person skilled in the art will see that many different types of fasteners could be used. The user would cut one of the two wires 14 of the power cord into two parts, and then expose the end of each piece by stripping a small portion of the insulation on the wire. Each end of the wire would then be attached to a wire-fastener. The other power wire of the apparatus would be left intact. The user would then replace and secure the base 18 to the housing 5 with screws, with the power wires of the apparatus passing through the holes 17 in the housing; the user could then operate the invention to both disrupt and restore power to the electrical apparatus, and also use the lock 8 and lock-bar 7 to fix the switch in an open or closed position.
Common power cords comprise two wires 14 and 15. Only one wire 14 need be cut to install the invention. The other wire 15 completes the larger circuit. A preferred example is the power cord to a television. Other possible uses include computers, DVD players, VCRs, power tools, ovens, stoves, electric heaters and electric fire simulators.
The purpose of the invention is to create an universal means for a user to control the function of an electric apparatus without the use of complex technology. This control relies on a mechanical or electronic means that is not subject to electrical failures or computer hacking. The mechanical means that is used is the lock bar 7. This lock bar 7 is a bar of durable material that cannot be broken by human strength. Some version of the lock bar 7 cannot be broken or cut by common tools. The lock bar 7 can be any shape or size, so long as it can fit into the first hole 2 and the second hole 3 in the toggle-handle 1 and into the hole 6 in the housing 5 and 16. A lock 8 immobilizes the lock bar 7. This lock 8 can be any kind of lock; it can be part of the housing 5 or it can be a separate lock.
The lock 8 can be any locking means. The lock 8 can be a lock controlled by a key or a combination. Alternatively, the lock 8 can be electrically powered and/or controlled by a computer or other human-controlled instrument. The type of lock 8 is not material to the invention. The preferred embodiment envisions a padlock as the lock 8 that can immobilize lock bar 7. Whatever the type of lock that lock 8 is, it must be able to immobilize the lock bar 7, or whatever else is physically affecting the characteristic of locking in either an “open-” or a “closed-switch” configuration.
Although this invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modification may be made which clearly fall within the scope of the invention. The invention is intended to be protected broadly within the spirit and scope of the appended claims.
