The present invention is related to a unique cable stripping device for stripping insulation from cables. Electrical cables are used in devices and buildings throughout modern society. Some cables distribute electrical power from power sources to homes and other buildings, while other cables are used to distribute the power throughout the buildings to receptacles, lighting and other equipment. Electrical devices also use cables to distribute electrical signals and power to and within the devices. Depending on the application, electrical cables can be installed by electricians, electrical equipment installers, builders and others.
Cables include one or more metal conductor and some type of electrical insulation. The conductor is typically mostly either copper or aluminum which carries electrical current with low resistance. The insulators can be plastic, rubber, polymers or another material that is substantially electrically non-conductive to protect the conductor from damage and to protect against unwanted current flow from the conductor. As used herein, the term “cables” should be understood to include wires which have one or more strands of an electrical conductive material that has an insulating cover along at least part of the length.
Since there are so many uses for cables, they come in a variety of sizes, types, and configurations depending on the application. Smaller cables for carrying relatively smaller current can have a single, solid strand or multiple strands of conductors using a common insulated cover. Larger cables for carrying relatively larger current typically have multiple larger conductors that are wound together and that are surrounded longitudinally by a common insulator. Both small and large cables can have a substantially round cross section. Other cables can have a combination of two or more cables surrounded by a common insulator, jacket or sheath. One example of such is non-metallic sheathed cable (also commonly called Romex, NM cable) which can also include a bare ground conductor along with two or more individually insulated conductors. The outer covering of NM cable is included when referring generally to insulators herein. Depending on the configuration, NM cable can have flat surfaces, and can have a non-round and/or asymmetrical, overall cross section.
There is an increasing demand for recycling metals in society. Some areas require certain materials to be recycled. Among the most recycled materials are metals, including copper and aluminum. Scraps of these metals, including scrap cable, can be sold for recycling, and naturally recyclers pay much more for pure aluminum and copper scrap than they pay for cable that includes the insulator. Applicant recognizes that recycling of scrap cable is more likely to occur if the insulation can be removed in a quick, easy and convenient manner.
Cable strippers can be used for removing the insulation from cables prior to recycling. Cable strippers for this purpose can be used for removing long lengths of insulation from conductors. These cable strippers should not be confused with common wire strippers that are used for removing a short section of insulation at an end of a cable for electrical connection since these common wire strippers are generally not suitable for stripping long lengths of insulation.
Conventional cable strippers suffer from a variety of flaws that make them inconvenient, time consuming, and/or difficult to use. Some conventional cable strippers are large machines that utilize a motor or hand crank to force the cable through the machine or to rotate a cutting assembly. These machines are large, expensive and inconvenient, and typically require time to set them up for a specific cable type. Other conventional cable strippers rely on specialized cutting wheels or blades that are expensive and inconvenient to use since they can only be obtained from the original manufacturer of the cable stripper. Some conventional cable strippers have to be adjusted for the size of wire to be stripped or have a series of slots for different sized cables which makes them bulky, inconvenient to use and time consuming. Some use adjustable spring mechanisms to force the blade and the cable together. These must be adjusted carefully so that the blade cuts just deep enough to split the insulator of round cross section cables. Many or all of these conventional cable strippers are unable to strip cables with non-round cross sections.
Another concern with conventional cable strippers are exposed blades which can be dangerous for the user, especially if the cable stripper is picked up without looking, as is common with tools that are held in a tool belt. Many of these conventional cable strippers offer no protections from the cutter, or have open channels or other shapes into which fingers can easily contact the cutter when the device is picked up.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon reading of the specification and a study of the drawings.
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
In general, a method and associated apparatus are described for stripping cable insulation from cable conductors of an electrical cable. A cable stripper can include a body which can define a portion of a cable passage. The passage can extend from a first end of the body to a second end of the body and the body can be configured for receiving the electrical cable in the passage. The cable stripper can also include a blade holder connected to the body and configured for holding a blade such that the blade is extendable into the passage to cut conductor insulation by applying a force to the blade holder. The blade can be retracted from the passage when the force is not applied to the blade holder. A gripper mechanism can be connected to the body. The gripper mechanism can define a portion of the cable passage and the gripper mechanism can be configured such that applying a force to the gripper mechanism extends the gripper mechanism and narrows a portion of the passage to position the electrical conductor relatively closer to the blade. Passing the electrical cable through the passage while extending the blade and applying the force to the gripper mechanism can cut the cable insulation and allow the cable insulation to be peeled away from the cable conductor.
A method for stripping insulation from a cable using a cable stripper is disclosed. The method includes inserting an end of the cable into a proximal end of a passage of the cable stripper. The cable can be pushed through the passage until the cable end extends from a distal end of the passage. A force can be applied to a gripper mechanism to extend the gripper mechanism and thereby position the cable under a blade. Another force can be applied to a blade holder to extend a blade into the passage and into the insulation of the cable. The cable can be pulled through the passage to cut the cable insulation along the length of the cable.
In an embodiment, a cable stripper is disclosed for cutting insulation of an electrical cable. A body defines at least a portion of a passage, the passage extends from one end of the body to another end of the body and can be configured for passing electrical cables longitudinally through the passage. A blade holder is included for selectively extending a blade into the passage and retracting the blade from the passage. A gripper mechanism is included for selectively moving electrical cables in the passage relatively toward and away from the blade. A cable guide is included and is configured for guiding electrical cables laterally toward the blade while the electrical cables are moving longitudinally through the passage. The cable guide can include a tapered shape that has a relatively wider recess away from the blade and a relatively narrower recess closer to the blade.
In addition to the example aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions
The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the described embodiments will be readily apparent to those skilled in the art and the principles taught herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein including modifications and equivalents, as defined within the scope of the appended claims. It is noted that the drawings are not to scale and are diagrammatic in nature in a way that is thought to best illustrate features of interest. Descriptive terminology may be adopted for purposes of enhancing the reader's understanding, with respect to the various views provided in the Figures, and is in no way intended as being limiting.
Attention is now directed to the Figures wherein like items may refer to like components throughout the various views.
To use the cable stripper,
Since the blade holder 32 and the gripper mechanism 34 are activated separately from one another, the user can adjust the amount of pressure exerted on either separately to optimize the cutting by separately feeling the cut and the grip of the cable. For example, if the cut is too deep and the blade is dragging on the conductor then the blade could be worn prematurely and the cable can be harder to pull than what is actually required to cut the insulation. Also, since the user can adjust the pressure exerted by the blade, the user has a feel for how the blade is positioned when cutting and it is therefore less likely for the cable to roll when stripping the cable. This is especially important when stripping relatively smaller cables since they have more of a tendency to roll when stripped than do relatively larger cables. The cable stripper 10 also allows the user to feel if the gripper mechanism is squeezing the cable too hard or not hard enough to position and/or slide the cable through the stripper.
The cable stripper is shown in
The blade 40 used with the cable stripper 10 is a common utility knife blade that has two mirror image pointed ends that allow the blade to be held by the blade holder with either end positioned for use. When one end becomes dull, the blade can be turned around so that the other end of the blade can be used. These utility knife blades can be found at most any hardware or home improvement store and are relatively inexpensive. This makes blade replacement an inexpensive and easy task.
The passage 42 extends through the body 22 (
Cable stripper 10 includes a cable guide 68 which includes a lower guide portion 70 that can be formed in the surface 62 of the gripper mechanism, and an upper guide portion 72 that can be formed in the surface 60 of the body. The cable guide 68 can have a generally conical shape that tapers from the proximal end of the passage to the distal end of the passage. The upper guide portion can be formed by the first and second sides of the body and can be mirror imaged across the joint 28 between the sides with each side defining approximately one part of the cone shape. In an embodiment, the conical shape of the cable guide is not regular, it is symmetrical left to right (side to side) but not top to bottom. Described another way, the portion of the cone defined by the body is not symmetrical with the portion of the cone defined by the gripper mechanism. In another embodiment, the conical shape of the cable guide can be symmetrical top to bottom as well as side to side. The conical shaped cable guide includes an opening in the upper guide portion through which the blade is extendable.
The gripper mechanism 34 is shown in
Gripper mechanism 34,
The gripper mechanism can include grip recesses 88 which engage a user's fingers when the cable stripper is used to help prevent the user's hand from slipping. The body 22 of the cable stripper can include a series of ridges 90 which can engage the user's palm to help prevent the user's hand from slipping.
The gripper mechanism can be made from a plastic, polymer, metal and/or other material. The gripper mechanism can be made from a material or can have a coating that has a reduced frictional resistance to the sliding motion of cable insulation to allow the cable to be guided through the cable stripper with less resistance than when other materials are used for the gripper 34.
The distal end 94 of the cable guide,
A side view of the cable stripper 10 is shown in
Cable 100 is shown in
The proximal end 92 of the cable guide 68,
A side view of the cable stripper 10 is shown in
The cable guide can include squared off sides in the intermediate profile which can be used for centering flat cables. A conical shape having squared off sides in the intermediate profile is shown in
Although the cable stripper has been discussed up to this point in a configuration in which the gripper is actuated by the user's fingers and the blade holder is actuated by the user's thumb, in another embodiment, the cable stripper can be configured so that the gripper is actuated by the user's palm and the blade holder is actuated by the user's index finger. In this configuration, the body can include finger recesses for the user's fingers and the gripper can be arranged to contact the user's palm so that the palm rotates the gripper about the axis to grip the cable in the passage. Also, in this configuration, the user's index finger and apply pressure as needed to press the blade into the cable insulation. The conical shape may be formed with the relatively smaller recess either as part of the gripper mechanism or the body.
The cable stripper includes separate hinged movement for the lower guide portion 70, as part of the gripper mechanism 34, and for the blade 40. Having separate hinged movement allows the user to apply as little or as much force as is needed to the gripper and blade independently from one another. This means that he cable stripper can be held and operated with a single hand. The gripper allows the user to control how hard the cable is pressed in the guide so that the user can feel how much force is needed to maintain the cable in the guide, centered under the blade while not applying so much force that it is overly difficult to pull the cable through the cable stripper. The gripper can also be used to hold the cable, without using the blade, while the user move their hand from pushing the cable into the proximal end of the passage to the distal end of the passage where the other hand (non-tool hand) can be used to pull the cable through the passage. The independent movement of the blade allows the user to feel how the blade is cutting the insulation so that only the minimum pressure necessary to cut the insulation is used and the blade is not pressed against the conductor with unnecessary force. By having the guide and the blade move independently from one another, the guide can force the cable against the opposite side of the passage while the blade is extended or retracted. The blade can be extended while the gripper is retracted against the stop. Also, the user can force the guide and blade toward one another such that the blade cuts the insulation without the guide forcing the cable against the upper passage surface, which can allow the user to have another type of feel for how the blade is cutting. The independent movement of the blade and guide allow the user to strip a variety of different cable configurations and sizes without prior set-up for each cable type as well.
Both the gripper and blade holder have bias springs. The blade holder spring is arranged to hold the blade out of the passage. The gripper bias spring is arranged to hold the gripper such that the passage is open to have the largest cross sectional area. The bias springs can have a relatively light resistance so that the user's feel for the guide and blade has less influence from the springs. Because the bias springs retract the blade and open the passage, the cable stripper is ready to have a cable inserted by sampling relaxing the user's grip and thumb pressure on the stripper.
Having the blade arranged to extend into a passage, and having the blade biased out of the passage allows the user to keep the cable stripper in a pocket or tool belt without substantial risk of cutting. In order for the blade to inadvertently cut the user, the user would have to insert an individual finger into the passage while the blade is extended, and the user is likely to feel a single finger entering the passage before the finger could reach the blade. Since the cable stripper can be safely kept in a pocket or tool belt, a user can have the cable stripper handy during installation of cables which can make it more likely that the scrap cables are stripped.
A method 110 is shown in
The method then proceeds to 120 where the cable is pulled through the cable stripper to cut the cable insulation along the length of the cable. The user can pull the cable through the cable stripper with one hand while applying even pressure on the gripper and the blade holder using the other hand. Method 110 then proceeds to 122 where the method ends. After the cable has been sliced the insulation can be removed from the conductor of the cable. Since the cable insulation is sliced or scored lengthwise, the insulation can be easily peeled away from the conductor. After the cable is pulled all of the way through the cable stripper, the user can ease off the pressure on the gripper and blade holder to allow them to return to the retracted positions. Then the user can insert another cable to repeat the stripping process.
The body, blade holder and gripper mechanism can be made from one or more plastic, metal and/or other materials. The sides of the body can be fastened together and the sides of the blade holder can be fastened together using screws, bolts or other fasteners or can be snapped together or held in another manner. The blade holder and gripper mechanism can be retained in the body by the first and second sides of the body.
The cable stripper does not require a screw or other adjustment to be set to a fixed position at a predetermined cutting depth prior to inserting a cable. The cable stripper is configured such that the user's hands are protected from accidental contact with the blade which allows the user to grab the cable stripper without having to look and make sure that they are not going to cut themselves. The cable stripper is relatively small and lightweight which allows the user to keep the cable stripper in a pocket or tool belt. The cable stripper uses common and inexpensive utility knife blades for convenience and economy. The cable stripper can be used to strip all of the cables that are commonly used in residential construction.
Various embodiments of cable stripper apparatus, and the use and construction of the apparatus, are disclosed herein which can be used for stripping insulation from cables. Applicants submit that the apparatus, systems and methods according to the present disclosure provide sweeping and heretofore unseen benefits that are not recognized by prior art.
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof.
The present application claims priority from U.S. Provisional Application Ser. No. 62/241,625, filed on Oct. 14, 2015 which is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
62241625 | Oct 2015 | US |