Patent Application
20210291395
The present invention relates generally to cutting tools, and more particularly to a new and unique skiver for precisely removing a thin layer of material from the outside of an elongated, tubular object such as a medical catheter.
In the manufacture of some products, such as medical catheters, for example, manufacturers may use a thin outer layer of thermoplastic heat shrink during construction of the products. In some circumstances, some catheters are formed using layers different materials, or have material changes along the length. The thin layer of thermoplastic is put on the product and heated to combine the multiple layers into one. This is called reflowing. The heat shrink pulls the product tight on a mandrel (metal or plastic rod in the center of the catheter) keeping it round. Similarly, some batteries are manufactured with such an outside layer to prevent electrical shorting before packaging. Such heat shrink is quite thin and tight on the product.
Some standard heat shrink can be removed by holding the product, making a small cut in the end of the layer to facilitate grasping the layer, then tearing the heat shrink in a spiral motion. This is nearly impossible on smaller devices, is time consuming and requires the use of an open blade. A peelable version of heat shrink has been invented to fix this problem. Peelable heat shrink requires a slit in the end of the heat shrink to create two tabs to grab on to. The tabs are then pulled perpendicular to the device to remove the heat shrink. This requires no open blades, but the peeled heat shrink can stretch up to three times longer in the perpendicular direction when compared to the starting length of the material. Removal with this method can be ergonomically undesirable as well as much more expensive than standard heat shrink.
Tools used for removing heat shrink have a sharp “tooth” or “shoe” that goes under the heat shrink. A vertical surgical blade is aligned with the sharp end pointing down the length of the catheter. The shoe or tooth is shoved between the heat shrink and the catheter dragging down the length. The shoe or tooth lifts the heat shrink and is slit by the blade. This type of skiving may leave drag marks along the length of the product and will dig into the product if not used correctly. They are made to order and are highly sensitive to the size of the machined channel matching the OD of the catheter exactly. Some skivers do not have a guard over the tooth and if one slips out of the heat shrink it can stab the operator if not careful. Thus, while various manual cutting tools for various purposes have been available heretofore, there has not been a tool that is specifically adapted for this purpose while avoiding possible injury to the user.
A need has thus arisen for a new and improved skiver for precisely and safely removing a thin layer of heat shrink or other similar material from products such as medical catheters, small batteries and the like without risking injury or damage.
The present invention comprises a new and unique skiver of improved construction which overcomes the foregoing and other difficulties associated with the prior art. In one embodiment in accordance with the invention there is provided a skiver with a body attached to the front end of a handle. A longitudinal recess is provided in the lower surface of the skiver body for guiding a catheter or the like past a transverse blade extending into the top of the recess as the skiver is advanced along the length thereof to precisely remove a thin layer of outside material such as plastic heat shrink without damaging the underlying catheter. In another embodiment of the invention the body of the skiver is attached to a table or other mounting system so that the skiver is supported either on a flat work surface or a separate mount. In another embodiment of the invention, a more automated skiver is provided. The skiver body is held in position and powered rollers advance the catheter or other object into the skiver. This embodiment is safe and efficient and protects the user from injury.
In the present invention, the precise placement of the blade as well as the angle of the blade allows the blade depth to be set to about half of the wall thickness of the material to be removed. When moving the tool along the length of the device (or moving the device along the tool), the blade will want to dig in deeper (due to angle of approach) and, in some instances, will lift (stretch) the heat shrink off of the part and cut off a strip of material allowing the remaining heat shrink to simply be pulled off the part. In contrast to prior devices which merely slice the material to be removed, the devices and methods of the present invention remove a section of the heat shrink.
In some embodiments, a skiver comprises a body having front and back ends and top and bottom surfaces. A longitudinal recess of a predetermined cross section is defined by the body. An opening in the body extends from the bottom surface to the recess. A blade is disposed in the opening. A pair of motorized rollers are arranged to move an object oriented in the longitudinal recess.
In some embodiments, a skiver comprises a body comprising a top surface, a bottom surface and a magnet. The bottom surface comprises a longitudinal recess and the top surface defines a blade recess. The magnet is adjacent to the blade recess. The body comprises an opening between the longitudinal recess and the blade recess. A blade is oriented in the blade recess. The blade comprising a cutting edge and a portion of the cutting edge is positioned in the opening. A cover is attached to the body, which comprises a lower surface. The top surface of the body and the lower surface of the cover secure the blade directly adjacent to the cutting edge.
In some embodiments, a skiver comprises a body comprising a longitudinal recess, a blade recess and an opening between the longitudinal recess and the blade recess. A blade is oriented in the blade recess. The blade comprises a cutting edge and a portion of the cutting edge is positioned in the opening. A cover is attached to the body that is arranged to secure the blade. A guide member is moveable with respect to the body. In some embodiments, a portion of the guide member extends into the longitudinal recess. In some embodiments, the guide member is positioned across the longitudinal recess from the blade. In some embodiments, the guide member comprises a guide pin, the body comprises a cavity and a portion of the guide pin is oriented in the cavity. In some embodiments, the guide member is moveable with respect to the body along a length of the guide pin. In some embodiments, the longitudinal recess comprises a longitudinal axis and the guide member is arranged to move orthogonal to the longitudinal axis. In some embodiments, a drive system is arranged to move an object oriented in the longitudinal recess.
In some embodiments, a skiver comprises a body comprising a top surface, a bottom surface and a central axis. The bottom surface comprises a longitudinal recess. The top surface defines a blade recess. The body comprises an opening between the longitudinal recess and the blade recess. A blade is oriented in the blade recess. The blade comprises a cutting edge and a portion of the cutting edge is positioned in the opening. A cover is attached to the body that comprises a lower surface. The top surface of the body and the lower surface of the cover secure the blade directly adjacent to the cutting edge and the longitudinal recess is laterally offset from the central axis. In some embodiments, the skiver comprises a second longitudinal recess extending parallel to the first longitudinal recess. In some embodiments, the central axis is centered between the first longitudinal recess and the second longitudinal recess.
A better understanding of the invention can be had by reference to the following Detailed Description in conjunction with the accompanying Drawing, wherein:
Referring now to the Drawings, wherein like reference numerals designate like or corresponding elements throughout the views,
When the skiver is used, the catheter 14 can be supported either on a flat work surface 20, or in a separate accessory as described below for better precision and in order to avoid possible injury to the user. As the tools of the present invention are safer than prior art skivers and the accessory can aid in the training of the people who will use the skiver by holding the tool at the correct angle while applying no (or very little) downforce.
The skiver 10 includes a body with handle 22 extending from its back end. The surface of handle 22 may be ribbed or textured to facilitate secure gripping by the user. The front end of the body of skiver 10 is relatively wider than handle 22, with a substantially flat or planar bottom surface 24 and an inclined flat front surface 26 in which the longitudinal recess 11 is located. Front surface 26 is preferably angled upward at an acute angle from surface 24. While various shapes can be used, the recess 11 is preferably semi-cylindrical in shape. The recess is dimensioned in accordance with the size of catheter 14 but the inventions herein allow some leeway. In a non-limiting example, the cross section can have a semicircle diameter of 0.185 inches. This cross section will accommodate a catheter or other device with diameters ranging from 0.075 to 0.18 inches. The catheter has to be slightly smaller than the cross section so that the surface of the material to be removed can touch the blade but can also be substantially smaller than the cross section. If the catheter is sized too much smaller than the cross section, the catheter may be unstable when moving past the blade.
A blade 28 is disposed in a transverse recess in the top of the front end of handle 22, the middle front position of which top recess intersects bottom recess 11, forming a small opening 30. The cutting edge of blade 28 extends into the opening 30, as best seen in
The blade 28 is preferably set at an angle of about 30 degrees from horizontal as shown, plus or minus about three to five degrees. From the view in
The blade 28 is secured beneath a removable cover 32 by a thumb screw 34 to the front end of handle 22 so that it can be replaced as necessary. A pair of laterally spaced apart dowel pins 36 are provided in the top recess for accurate alignment of blade 28.
The depth of extension of blade 28 into the opening 30, and thus the depth and width of the cut can be adjusted by means of shims or height adjustment elements 38, two of which are shown for purposes of illustration, although any suitable number can be used. The shims 38 can be made from stainless steel or any other suitable material in thicknesses ranging from two to ten thousandths of an inch each. In some embodiments, the shims have a small notch located on the side that is adjacent to the sharp end of blade 28. See
Button 56 can be used to move jaw 46 away from skiver 10 to aid in inserting a catheter or other device into the skiver. If not attached to bracket 42, the user can hold the assembly in one hand while pulling the catheter or other object through the skiver and out opening 60.
After the blade depth has been adjusted as desired, the skiver 10 can then be secured within mount 40 by bolts 62 before or after being secured to bracket 42 by bolts 64, as desired.
Skiver 66 includes a raised body 74 supported on legs 76 secured thereto by screws 78. Rubber feet 80 are provided on at least the bottom ends of legs 76.
The underside of body 74 includes a slidable adjustment block 82 guided within recesses and biased by magnets 84, as shown in
A blade 91 is provided on the angled side of an opening 92 extending through body 74, held in place by a cover 94 secured with screws 96. A portion of opening 92 intersects with the longitudinal recess 72. With screw 86, the blade 92 and cover 94 can be set in the desired position with the edge of the blade extending though opening 92 and into recess 72, after which the adjustment block 82 is locked in place with screw 98.
Again, blade 91 is preferably set at an acute angle of about 30 degrees, or about 25 to 35 degrees, of inclination so that battery 70 can then be advanced across skiver 66 to quickly cut a longitudinal section in the heat shrink material 68 and thus facilitate its removal from the battery.
A longitudinal recess 109 is provided in the underside of block 106 for receiving the catheter or other device 14.
The skiver 10 is threadedly secured to block 106 by screws 110 extending upwardly through openings in the block into holes 112 in the underside of the skiver, as best shown in
Rubber feet 114 are preferably provided on the bottom of body 102 to resist sliding of the mount 100. An optional hole 116 can also provide to facilitate positively securing mount 100 to work surface 20 with a bolt (not shown) or the like, if desired.
A set screw 118 is provided for fine adjustment of the angle of the skiver 10 when used with mount 100. The set screw 118 extends upwardly through an opening in block 106 into engagement with the underside of skiver 10 after attachment to the block.
The smaller diameter at the landing pad 166 as compared to sections 162 and 170 allows heat shrink removal from tapered parts. A catheter with a construction changing from a smaller diameter to a larger diameter will not lift the catheter out of the blade due to the short length of the landing pad. The same concept applies for a catheter design with a diameter changing from a larger first diameter and tapering down to a smaller diameter. Without the smaller diameter landing pad 166 guide 144 would be held open by the larger catheter until it left body 150 at the exit of section 170. The maximum size of a device to be skived is limited by the size of landing zone 166; the device must be slightly smaller than the size of opening 166 so that it can access the blade.
When using a blade such as a razor blade on an object, the blade has a tendency to ‘dive’ into the object. In the embodiments of this invention, the blade and object are relatively held in place, so this does not happen to a large extent. Applicant has found, however, when using the skiver on a device that has only a thin layer of material to be removed, the layer to be removed will pull away from the device and toward the blade. This will cause a vacuum to be formed under the material. As the device continues to move over the skiver, often the material to be removed will move so far away from the device that the blade will extend all the way through the material. However, since the blade and the device are held a constant distance apart, the blade will not damage the device. This is shown in
The embodiments described herein have wide applicability to a variety of catheters and other devices which have a layer of material to be removed. In some embodiments, FEP (fluorinated ethylene propylene) is removed from the outside of a medical catheter. In some instances, the FEP has a thickness of 0.009 +/−0.002 inches. In this instance, the blade of the skiver will be set to a depth of about 0.0045 inches, or about 50% of the depth of the FEP. In other instances, a polyolefin with a thickness of about 0.009 inches is removed from the outside of a device. In this instance, the blade is set to a depth of 0.006 inches, or about ⅔ of the thickness of the polyolefin. These dimensions are merely examples. Applicant has found that setting the blade depth between ¼ and ¾ of the thickness of the material to be removed is generally acceptable.
Many of the recesses shown herein has a semicircular cross section. However, the invention is not limited to semicircular cross sections. In some embodiments, the cross section can be oval, an arc of a circle less than 180°, a flat surface, or a cross section with straight sides that join together at a peak in the area of the blade.
Many of the embodiments described herein have been described as being directed to a catheter or other round medical device or to a pack of batteries. The inventions, however, are not so limited. The devices of the invention can be used to open packaging (for example surgical scissors with heat shrink over the tips) and on fiber optics and other types of cables with a thin plastic exterior.
In many of the embodiments herein, the catheter or other device to be skived does not need to be of constant diameter. For example, the skiver of
As discussed above, prior art skiving apparatus and methods can include the use of a blade to cut the material that is to be removed. In the embodiments herein, the skive operator is protected from the blade and is much less likely to be injured during the skiving process. In the automatic skiver operation, it is very unlikely that the skiver operator can be injured as the blade is not readily accessible.
From the foregoing, it will be appreciated that the present invention comprises an improved skiver having several advantages over the prior art. The skiver herein is adjustable and precise. It facilitates removal of thin material from the outside of a product while minimizing if not avoiding possible damage to the product and/or injury to the user. It can also be used to cut a precise longitudinal slot in the wall of a product. The skiver herein can be handheld, used with a separate mount or automated. Other advantages will be apparent to those skilled in the art.
In the detailed description of the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration how one or more embodiments of the disclosure may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the embodiments of this disclosure, and it is to be understood that other embodiments may be utilized and that process, electrical, and structural changes may be made without departing from the scope of the present disclosure.
As used herein, designators such as “X”, “Y”, “N”, “M”, etc., particularly with respect to reference numerals in the drawings, indicate that a number of the particular feature so designated can be included. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an”, and “the” can include both singular and plural referents, unless the context clearly dictates otherwise. In addition, “a number of”, “at least one”, and “one or more” (e.g., a number of pivot points) can refer to one or more pivot points, whereas a “plurality of” is intended to refer to more than one of such things. Furthermore, the words “can” and “may” are used throughout this application in a permissive sense (i.e., having the potential to, being able to), not in a mandatory sense (i.e., must). The term “include,” and derivations thereof, means “including, but not limited to”. The terms “coupled” and “coupling” mean to be directly or indirectly connected physically or for access to and movement of the movable handle member, as appropriate to the context.
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that an arrangement calculated to achieve the same results can be substituted for the specific embodiments shown. This disclosure is intended to cover adaptations or variations of one or more embodiments of the present disclosure. It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description. The scope of the one or more embodiments of the present disclosure includes other applications in which the above structures and processes are used. Therefore, the scope of one or more embodiments of the present disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.
In the foregoing Detailed Description, some features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the disclosed embodiments of the present disclosure have to use more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
This application claims the benefit of U.S. patent application Ser. No. 16/873,334, filed Mar. 20, 2020, the entire content of which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16873334 | Mar 2020 | US |
| Child | 17206060 | US |
