Patent Grant
6855895
The lanyard of the present invention relates in general to electrical shut-off means typically associated with industrial machinery and which allows a workman to easily shut off electrical current to the machine for safety purposes during servicing or repairs. However, the present lanyard more particularly pertains to an accessory device that can be easily installed on site and fixedly attached onto a typical on/off switch associated with an overhead electrical switch box. The lanyard is of simple construction and is made from insulated components so as to eliminate any possibility of accidental electrical shock. The lanyard when in the off mode insures that the on/off switch cannot be accidentally moved into the on position, and when in the on mode insures that the on/off switch remains in operating position, thus allowing for electrical current for energizing machinery, unless there is a power failure.
Switches are used in many applications to control the flow of electrical energy. The switches can be used to redirect electrical energy from one circuit to another, and can be used to stop the flow of electrical energy through a circuit. In both cases the circuits become de-energized, that is without a voltage. One particular type of switch is a circuit breaker which cuts off the flow of electrical energy when the flow of electrical energy through the switch exceeds a predetermined value. Many of these circuit breakers include a lever which is movable between an “On” position and an “Off” position.
Maintenance personnel often use a circuit breaker to cut the flow of electrical energy through a circuit when the circuit, or electrical components connected thereto, require maintenance. The circuit breaker, however, is often remote from the location requiring maintenance. Therefore, it is desirable to lock out the circuit breaker to prevent an individual from inadvertently energizing the circuit while maintenance is being performed.
Known circuit breaker lock out assemblies engage the circuit breaker lever to prevent unauthorized movement of the lever. Lockouts such as disclosed in U.S. Pat. Nos. 5,593,020; 5,794,760, and 5,900,600, include a lock arm cantilevered from a lock rail. The lock arm includes a head that engages or covers the circuit breaker lever to prevent unauthorized movement of the lever. The lock out devices as taught within the cited references, can easily be circumvented by lifting the cantilevered head away from the lever and thus disengaging the lever from the head. As a result, the lock out adequately serves to provide notice to an individual that movement of the lever is unauthorized, however, it is not always effective to prevent unauthorized lever movement.
Another disadvantage of the prior art cantilevered lock out device is the inability to lock out adjacent circuit breakers aligned along an axis perpendicular to the lock rail. Only one opening in the lock rail can be used to hold a cantilevered lock arm, and each lock arm can lock out only one circuit breaker. In addition, the prior art cantilevered lock out assemblies disclosed in the above referenced patents, are very complicated and use numerous parts that the present invention clearly eliminates.
Another type of an electrical lockout device is taught within U.S. Pat. No. 5,451,730 entitled “ELECTRICAL SAFETY APPARATUS” which substantially teaches an elongated insulated rod having an upper disconnect hook to engage a handle of a switch box. This apparatus is functional for its intended use but still has inherent disadvantages and drawbacks that the present invention recognizes, addresses and resolves in a manner not heretofore taught. For example, this type of lockout apparatus does not provide a suitable locking mechanism such as a typical pad lock, and due to strict regulations it is unlikely this apparatus would be allowed or approved. The locking mechanism is simply a curved bar which is held in a locked position by a tension spring. Thus, use of a spring is not effective as springs tend to easily wear out and the tension is variable which is most unfortunate as this results in an inefficient locking mechanism.
One of the most important drawbacks of the known prior art is the fact that the workman must be within arms reach of the electrical disconnect box so as to be able to shut the switch off and then attach a pad lock. This is very important as “Osha” regulations are very clear and precisely state that a pad lock or the like must be incorporated for a safe and secure lockout. This can be very difficult because most industrial facilities have pallets, crates, materials and other obstacles between the affected machines. Thus, such items must be removed and/or re-positioned so as to allow the workman access to the electrical disconnect box. This not only results in increased cost and loss of valuable time but is also dangerous for the workman as they must further climb onto a step ladder or the like to obtain proper height for attaching the pad lock.
It is therefore contended that a need exists for a new and improved type of lockout device that may be used for disconnecting overhead electrical switches and which eliminates the inherent drawbacks and disadvantages of the known prior art. It is further contended that such a lockout device should be durable, safe, easy to use and inexpensive to manufacture. It is also important to provide simple assembly and installation instructions, such as taught within the forthcoming specifications.
It is therefore a primary object of the present invention to provide an electrical lockout lanyard that allows a workman to easily shut off an overhead electrical disconnect box without the need to physically attach a pad lock directly onto the box.
It is another object of the present invention to provide an electrical lockout lanyard that may be easily installed and assembled on site without the need for any specialized skills or tools.
Yet another object of the present invention is to provide an electrical lockout lanyard that is adaptable for use on site as it is not limited to any specific length and is easily adjusted for ultimate performance by the workman upon installation.
Still another object of the present invention is to provide an electrical lockout lanyard that does not require any modifications of either the disconnect box or the machinery associated therewith.
A further object of the present invention is to provide an electrical lockout lanyard that once installed is permanent and then only used if needed. This is important, as if there is a need to quickly shut the off the power, the lanyard is easily accessible and provides instantaneous shut off. This is very different than the noted prior art that is very time consuming to use and does not allow for fast and easy access.
Yet another object of the present invention is to provide an electrical lockout lanyard that is of very simple construction, and is made from all insulated materials so as to eliminate any accidental electrocution.
It is a very important object to provide an electrical lockout lanyard that is approved for use by “Osha” and meets all requirements and regulations. In fact it may perhaps become mandatory, as it is a life saving device and it is much more desirable and advanced than the known prior art.
Another important object of the present invention is to provide an electrical lockout lanyard that is made from inexpensive materials so as to be cost effective for manufacture, sales and marketing.
Still a further object of the present invention is to provide an electrical lockout lanyard that may be sold and produced as a kit having all the necessary components for installation and instructions for assembly included therewith.
Yet a further object of the present invention is to provide a method of use as taught within the forthcoming specifications.
Other objects and advantages will be seen when taken into consideration with the following specification and drawings.
Referring now in detail to the drawings wherein like elements pertain to like characters throughout the various views. The present invention is substantially a universal electrical lockout lanyard (10) for use in combination with a typical overhead electrical disconnect switch (12) for positively shutting off electrical current there from for maintenance, repairs or the like.
Overhead electrical disconnect switch (12) is of the prior art standard type having a lever (14) which when in the “on” position allows electrical current to flow there from and when in the “off” position does not allow electrical current to flow. This standard type of electrical disconnect further includes a locking latch mechanism (16) which is of a shape and size to receive a pad lock (not shown) therein and is used for locking lever (14) into either the “on” or “off” position.
It is to be noted different embodiments may easily be conceived for the present invention, such as electrical lockout lanyard (10) may simply be formed from one elongated insulated member having a locking apparatus on each of its ends, whereby one end thereof is fixedly attached onto the locking latch mechanism (16) and the opposing end is removably affixed onto a first pad lock receiving latch (28) and then locked into position with a pad lock (32) with the latter latch being located at a position of workman's choice. Whereby, when lever (14) is in the off position and the opposing end is locked onto first pad lock receiving latch (28) electricity is positively shut off and lever (14) cannot be moved into the “on” position until the pad lock (32) has been removed.
Thereafter, when the technician desires to return lever (14) into the its operating “or” position, they must first remove the lock (32) and then re-position the opposing end onto a second pad lock receiving latch (30), attach pad lock (32) onto second pad lock receiving latch (30) and then return the lever (14) back into its operating “on” position which automatically restores electrical power.
The preferred embodiment as taught herein includes electrical lockout lanyard (10) being of simple construction and when assembled substantially comprises a first elongated cable section (18) having a first end (18-A) and a second end (18-B). First end (18-A) being threadably affixed and secured within a first clamp lock member (20) and second end (18-B) being threadably affixed and secured within a coupling member (22). A second elongated cable section (24) having a first end (24-A) and a second end (24-B). First end (24-A) being threadably affixed and secured within a second clamp lock member (26) and second end (26-B) being threadably affixed and secured within coupling member (22).
It is to be understood each of the cable sections (18 & 24), clamp lock members (20 & 26), and coupling member (22) can be made from any suitable material of engineering choice, such as plastic or Nylon™ etc., thus the following is only exemplary of some possible materials of choice. However, after extensive research and evaluation of cost and manufacturing, it has been determined that the preferred embodiment incorporates the following materials and construction method of choice.
As taught herein, first cable section (18) is made from a plastic vinyl cable having an outside diameter of 0.155 respectively. Second cable section (24) is made from a vinyl coated steel wire rope having an outside diameter of 0.250, respectively and clamp lock members (20 & 26) and coupling member (22) are each made from Delrin™ material.
It is to be further understood the electrical lockout lanyard (10) may be manufactured and sold as a kit, wherein the above noted components are provided yet the kit further includes 12-{fraction (10/32)}×⅜″ set screws, 1-0.155 thimble, 1-0.250 thimble and full assembly instructions, each of which are herein latter described.
Referring now to the actual construction of each of the noted components. As depicted in
As depicted in
Referring now to
For further clarification and as depicted in
It is to be noted additional options maybe included depending on engineering and consumer needs. For example, second clamp lock member (26) may be color-coded having its front side colored green and its backside colored red. It is to be noted the color-coding can either be embedded as part of the manufacturing process or it may be in the form of removable adhesive stickers or tags, etc. Whereby, when a workman is currently working on the machine he would display the red side, this in turn visually notifies people in the surrounding area that they must not turn on the power or the machinery. However, the green side is to be displayed when the workman has finished the job and power has been restored, thus notifying people in the surrounding area that all is in operating order and they may operate the machinery. Another option may be to include identification or advertisement labels having pertinent information thereon pertaining to either the device itself, the company of manufacture, or the company using the product, etc.
As previously noted, we will now address the actual assembly and installation method. The following method steps are for assembly and installation of an electrical lockout lanyard which is an accessory device that can be easily installed on site and fixedly attached onto a typical on/off switch associated with an overhead electrical switch box and allows a workman to easily either shut the power off or on. The lanyard (10) may simply be formed from one elongated insulated member having a first locking apparatus and a second locking apparatus, whereby one end thereof is fixedly attached onto the locking latch mechanism (16) on an overhead disconnect box and the opposing end is removably affixed onto a first pad lock receiving latch (28) and then locked into position with a pad lock (32) with the latter latch being located at a position of workman's choice. Whereby, when lever (14) is in the off position and the opposing end is locked onto first pad lock receiving latch (28) electricity is positively shut off and lever (14) cannot be moved into the “on” position until the pad lock (32) has been removed. The method steps comprising:
For further clarification, the above method steps also include the following assembly steps to be performed prior to step “a” above, comprising:
For still further clarification, the first method steps (a-o) above further include the following assembly steps that are used for attaching the first locking apparatus (20) onto locking latch mechanism (16), (see step “c”) comprising of the following steps;
For still further clarification, the first method steps (a-o) above further include the following assembly steps that are used for determining the location of choice for second locking apparatus (26) when it is to in the “off” position, comprising the assembly steps as follows:
Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made there from within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatuses.
This application is derived from our provisional application No. 60/478,406 filed on Jun. 16, 2003 and is now hereby to be converted to a full Utility patent as follows:
| Number | Name | Date | Kind |
|---|---|---|---|
| 4195192 | Hackney et al. | Mar 1980 | A |
| 4806710 | Kalvaitis et al. | Feb 1989 | A |
| 5293011 | Mokert | Mar 1994 | A |
| 5412167 | Mueller et al. | May 1995 | A |
| 5432308 | Howie, Jr. | Jul 1995 | A |
| 5772007 | Frye | Jun 1998 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20040251116 A1 | Dec 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60478406 | Jun 2003 | US |
