The present patent document relates generally to clamps and bushing inserts for use with clamps and methods of making the same. More specifically, the present patent document relates to a high temperature clamp and bushing inserts for holding sensors, cables and other objects and methods for making the same. In preferred embodiments, the bushing inserts are designed to secure sensors, cables or other objects in a clamp in a high temperature situation.
In many applications, sensors, thermistors, wires, cables, cabling or other objects need to be secured by clamps. In situations where temperatures are extremely high, standard clamps and bushings cannot be used. For example, above 600° F. Teflon clamps or bushings cannot be used. To this end, in applications where bushings are needed to be used in conjunction with clamps, both must be made of metal or other heat resistant materials.
Objects of the present patent document are to provide an improved bushing and/or clamp design. In particular, objects of the present patent document include providing an improved bushing and/or clamp design for high temperature applications. The bushings are designed to be used in clamps of various designs and secure sensors, thermistors, cables, wires, tubes or other objects securely in the clamp. Preferably, the new design eliminates or at least ameliorates some of the problems with the existing bushing and/or clamp designs as explained above.
To this end, a new bushing design is provided. In one embodiment, the bushing comprises a body formed from a single piece of metal the body having an “M” shaped cross-section with a first outer leg, second outer leg, first inner leg and second inner leg, wherein the first outer leg and second outer leg are both concave arcs about a central axis and form an outer circumference of the body and wherein the first inner leg and second inner leg each have an arc formed in the leg to create a rounded channel that extends a longitudinal length of the body along the central axis; and wherein the first inner leg and second inner leg transition between each other in a third concave arc. The rounded channel formed by arcs of the inner legs is used to secure the sensors, cables, thermistors, wires, tubes or other objects within the clamp.
In yet another embodiment, a bushing is provided that is formed from a single piece of metal with an “S” shaped cross-section wherein the “S” shaped cross-section has an additional element added to the tail of the “S”. The center portion of the “S” shaped cross-section and the additional element added to the tail run parallel to each other across an interior of the bushing and have opposing arcs that form the central passage for holding sensors, tubes, wires, cables or other elements.
In yet another embodiment, another bushing is provided that is formed from a single piece of metal with an arc that sweeps through 320 degrees or more where the arc defines the outer cylindrical shape of the bushing. A rounded interior passage is formed by opposing arcs in the interior of the bushing where each end of the outer arc turns inward and across the interior of the bushing.
In addition, a new clamp design is provided herein. In a preferred embodiment, the clamp comprises a top with a body and at least one upper arm that is cantilevered away from the body. The body has a through hole in it. The clamp further comprises a base separate from the top wherein the base has a bottom body and at least one lower arm cantilevered away from the bottom body. The base has a stud affixed to the bottom body of the base at a first end and extending therefrom to a distal end. The distal end of the stud is designed to permanently capture a fastener. The fastener is coupled to the stud such that the fastener can selectively translate along the longitudinal axis of the stud. A first mating interface extends away from the top or the base, wherein the top is coupled to the base by placing the through hole down over the stud and permanently capturing the fastener between the first end and the distal end of the stud. The top and base are oriented such that the at least one upper arm and at least one lower arm are aligned.
In preferred embodiments of the clamp, the stud is threaded and the distal end is deformed to capture the fastener. The fastener is preferably a nut.
Although the upper arms and lower arms can be in any shape, they are typically mirror images of each other and are designed to mate in a clam shell fashion to hold an object such as a bushing. In preferred embodiments, the at least one upper arm is a first arc and the at least one lower arm is a second arc. The two arcs oriented one over the other to form a majority of a circle designed to clamp against the outside diameter of a bushing.
In preferred embodiments, the first arc has a first end coupled to the body and the first arc is swept through between 150 and 180 degrees. In even more preferred embodiments, the second arc has a first end coupled to the base and is also swept through between 150 and 180 degrees.
The embodiments of a clamp may further include at least one mating interface. In preferred embodiments, the mating interface is cantilevered away from the top or the base.
In some embodiments, when the top of the clamp is assembled to the base and the fastener is fully tightened, a gap remains between a first distal end of the at least one upper arm and the at least one lower arm. This allows the upper arm and lower arm to act like springs around the bushing they are clamping.
Depending on the clamp embodiment, the clamp may have any number of upper and lower arms to secure any number of bushings. In preferred embodiments, the clamp has two upper arms on opposite sides of the top and two lower arms on opposite sides of the base.
In preferred embodiments. the two upper arms are arcs and the two lower arms are arcs and the axes of rotation of the two upper arms are in the same first plane and wherein the axes of rotation of the two lower arms are in the same second plane. In yet even more preferred embodiments, the first plane and the second plane are the same plane.
Although the clamps may be formed from any number of known manufacturing methods, in preferred embodiments, the top and base of the clamp are made from formed sheet metal.
The present patent document discloses embodiments of a bushing for use in securing wires, cables, sensors, thermistors, tubes or other objects within clamps. The bushings and clamps are particularly designed for high temperature applications. An example of a high temperature application is temperatures above 600° F. Under such conditions, typical Teflon bushings and/or clamps will melt and thus, more robust bushings and clamps are needed. The embodiments of bushings and clamps disclosed herein are designed for use in these high temperature applications.
In preferred embodiments, the high temperature bushing/insert is a formed part and may be formed from a thin sheet metal. However, in other embodiments, the bushing may be extruded. The bushings can be used in any type of existing clamps, such as p-clamps or dual sensor clamps. The high temperature bushing is designed to snap on to and stay attached to the tubing prior to the installation of the clamp. In preferred embodiments, the bushing is also designed to prevent lateral movement in the clamp and has a strain/stress relief feature to prevent chafing of the supported element.
The bushing can be made from any corrosion and heat resistant material. In preferred embodiments, the bushing is made from a metal, for example, stainless steel, Inconel, aluminum or other type of metal.
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Although the cross-section of the embodiment shown in
In some embodiments, the third concave arc 46 is an arc through 180 degrees or more around a longitudinal axis 50. This creates a rounded curve. In other embodiments, the third concave arc 46 may pass between 150 and 180 degrees.
In the embodiments with an “M” shaped cross-section the first inner leg and second inner leg each have an arc 52 and 54 formed in the leg to create a rounded channel 60 that extends a longitudinal length of the rounded body 32 along the central axis 42. The rounded channel 60 is designed to mate with the cable, wire, sensor, thermistor or other object held by the bushing. In preferred embodiments, the size and shape of the central channel 60 is designed to create an interference fit with the cable, wire, sensor or other object. The interference fit between the bushing and the cable, wire, thermistor, sensor or other object will allow the bushing to clip-on to the object while the clamp is being installed.
Depending on the material used, the central channel may also apply a spring force on the object being held. For example, if the diameter of the object placed in the bushing 30 is slightly larger than the diameter of the rounded channel 60, the two halves of the bushing 30 may be slightly pulled apart by bending the bushing 32 at the third concave arc 46 and placing the item in the rounded channel 60. Assuming the appropriate material is used for the bushing 32, the third concave arc 46 will apply a spring force against the object placed in the rounded channel 60.
In some embodiments, the radius of the rounded channel 60 and the radius of the third concave arc 46 are about the same. This allows the first inner leg 36 and second inner leg 38 to be approximately parallel to each other or only slightly converging or diverging. In many embodiments, the first inner leg 36 and second inner leg 38 are within 10 degrees of parallel and even more preferably within 5 degrees of parallel.
In preferred embodiments, the bushings include tabs 62, 64, 66 and 68 on opposite ends of the body 32 of the bushing 30. These tabs may be on both the top and bottom of the bushing 30 or in some embodiments, only a single set of tabs, for example 62 and 64 on either the top or bottom of the bushing 30. Although the embodiments shown have four tabs, any number of tabs may be used. In some embodiments, 8 tabs, four on each end, may be used. In yet other embodiments, six, ten, twelve, fourteen or sixteen tabs may be used.
The tabs prevent the bushing from moving laterally within the clamp when they are assembled together. The tabs are designed to stick out and away from the body of the bushing on either side of the clamp the bushing is assembled to such that the bushing cannot slide along the longitudinal axis in either direction.
To this end, a preferred embodiment of a bushing 30 includes a first tab 62 and a second tab 64 on opposite ends of the first outside leg 34 and extending outwards from a first outside edge 70 of the first outside leg 34 and a third tab 66 and a fourth tab 68 on opposite ends of the second outside leg 40 and extending outwards from a second outside edge 74 of the second outside leg 40.
In preferred embodiments, the rounded channel 60 has a flared lip 56 and 58 (the flared lip on the opposite end of the body 32 of bushing 30 is not shown in
In the embodiment shown in
In preferred embodiments, the bushing is a one-piece design. However, other embodiments may use a two-piece design. In yet other embodiments, even more pieces may be used. As used herein, a one-piece design means the entire body of the bushing is made from a single piece. That tabs 62, 64, 66 and 68 are not required to be made from the same piece of metal to satisfy the one-piece design criteria as used herein. In preferred embodiments, tabs 62, 64, 66 and 68 are in fact made from the same piece as the body and are just bent into place. However, in other embodiments, which would still be considered a one-piece design, the tabs are welded onto the body.
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In preferred embodiments, both a top side 84 and a bottom side 86 extend out laterally from the first concave portion 46 to an opposite side 82 of the bushing 30 from the first side 80. Once the top side 82 and bottom side 84 reach the opposite side 82, they each curve back on themselves to form a first convex portion 42 and second convex portion 44 on the second side of the bushing. The first convex portion 42 and second convex portion 44 are above and below the first concave portion 46 respectively. The radius of convex portions 42 and 44 may be any radius and the convex portion may sweep through any arc. However, in preferred embodiments, the convex portions sweep through an arc between 90 and 150 degrees and more preferably between 120 and 150 degrees. Regardless, the convex portions sweep through an arc of at least 90 degrees or more. The radius of convex portions 42 and 44 may be any radius but in a preferred embodiment the radius is about the same as the radius of the concave portion 46. In preferred embodiments, convex portions 42 and 44 are identical mirror images of each other.
After reaching the opposite side 82 and curving through the convex portions 42 and 44, both the top side and bottom side extend laterally back to the first side 84 of the bushing 30 in a first arc 34 and second arc 40 on a top 84 and bottom 86 of the bushing 30 respectively. As may be seen in
In the embodiment shown in
In preferred embodiments, the third and fourth concave arcs 56 and 54 each have a radius around the central axis 42 approximately equal to the radius of the concave portion 46. In other embodiments, the radius used for the concave arcs 56 and 54 may be larger than the radius of the concave portion 46. In preferred embodiments, the third concave arc 56 and fourth concave arc 54 each have a flared lip on a first end of the bushing 30. Even more preferably, the third concave arc 56 and fourth concave arc 54 each have a flared lip on both ends of the bushing 30.
The two concave arcs 106 and 108 are connected by the first central portion 112. The first central portion 112 and the second central portion 104 together form the rounded passage for holding the sensor, tubing, wires etc. While the first central portion 104 forms the center of the “S” in the cross-section, the second central portion 104 is an extension to the end of the “S” in the cross-section. Thus, the second central portion 104 is the portion of the cross-section that is not part of the “S” shape.
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Where the arc stops curving around the circumference of the body 202, the arc transitions into rounded corners 220 and 222 at each of its ends. The first rounded corner 220 transitions the arc 202 into the first central portion 224 and the second rounded corner 222 transitions the arc 202 into the second central portion 226. In the embodiment shown in
In the embodiment shown in
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The clamp 400 is designed with no loose parts. As use herein “loose parts” means no parts that may become detached from the assembly. All the parts in the assembly of the clamp 400 are designed to be permanently retained by the assembly. Although parts can be “loosened” to create additional clearance between parts, no parts can be separate or detached from the assembly.
The clamp 400 is designed to be a low-cost option where clamps with loose parts are not desired. In preferred embodiments, the base 402 and the top 404, which may also be called the cover 404, are made from formed sheet metal. In other embodiments, they may be machined from a block, pressed, made using additive manufacturing, or made using any of a number of well-known fabrication methods.
In preferred embodiments, the clamps 400 are made from aluminum or steel. This is primarily because the clamps 400 are particularly designed for use in harsh environments like on an aircraft. However, in other embodiments, the clamps 400 made be made from other materials such as plastic, resin or the like, or other low temperature materials without departing from the scope of the teachings herein.
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Although in preferred embodiments, the arcs of the arms are swept through similar angles such that the upper arm and lower arm are the same and basic mirror images, in other embodiments, the arcs may be swept through different angles such that the top or bottom is smaller and its corresponding side bigger. For example, the embodiment shown in
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The assembly of the clamp 400 further comprises a base 402. The base 402 is a separate part from the top 404. Similar to the top 404, the base 402 comprises a bottom body 422 (not shown in
The arms of the bottom body 422 and arms 424 of the base 402 are designed to generally be the mirror image of the top 404. Similar to a clam shell configuration where the two halves of an assembly mate together, the top 404 and base 402 of the clamp 400 are designed to mate together to hold a bushing or other object and thus, are mirror images of each other in the body 422 and arm(s) 424.
The base 402 further comprises a stud 426 affixed to the bottom body 422 of the base 402 at a first end and extending therefrom to a distal end, the distal end 428. The stud 426 is designed to permanently capture a fastener. The fastener shown in
As may be appreciated a fastener 420 is coupled to the stud such that the fastener 420 (in this embodiment a nut) can selectively translate along the longitudinal axis of the stud 426. In embodiments that use a nut as the fastener 420, the stud 426 may be threaded to accommodate the nut 420.
In preferred embodiments, the stud 426 is permanently pressed into the base 402. This may be done by press fit, interference fit or any other type of pressing. In other embodiments, the stud 426 may be permanently attached to the base using other methods such as welding or the like. In yet other embodiments, the stud may be removably attached to the base as long as its secure such that it won't come loose during normal conditions.
As is known in the art, the nut 420 may include a nylon portion or other device to prevent the nut from loosening once tightened.
During assembly, the 404 and a fastener 420 will be installed on to the stud 426 and the distal end 428 of the stud 426 will be deformed to keep the fastener 420 and the top 404 captive.
In preferred embodiments, the clamp includes a first mating interface 430 cantilevered away from the top 404 or the base 402. In the embodiment shown in
In the embodiment of
In the embodiment shown in
When the parts of the clamp 400 are assembled together, the top 404 is coupled to the base 402 by placing the through hole down over the stud 426 and permanently capturing the fastener 420 between the first end and the distal end 428 of the stud 426. This is typically done by deforming the distal end 428 of the stud 426. In the case of a threaded fastener like a nut, the distal end 428 can just be flattened such that the threaded fastener cannot come loose or be separated from the stud 426.
When assembling the top 404 to the base 402, the top 404 and the base 402 should be oriented such that the upper arms align with the lower arms. By align, it is meant that the upper arms and the lower arms are oriented to form a clam shell to receive an object such as a bushing.
In the embodiment shown in
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In the examples herein, the clamp 400 was described in relation to holding one or more bushings. However, the bushings are not contemplated as being part of the clamp invention by itself and one will appreciate that the clamp could be used to hold anything, such as a bare cable, not just a bushing. To this end, although reference to holding a bushing was used in describing the clamp, the clamps are in no way limited to holding a bushing either in design or application.
In yet another embodiment, the mating portion may be located on a separate part from the top 404 and the base 402. The separate part comprising the mating interface has a through hole and slides over the stud and is sandwiched between the top and the base during assembly. This allows the mating interface part to rotate around the stud and base such that the mating interface flange can be located at any angle with respect to the arms on the top and base. In preferred embodiments, the separate part may have features such as notches or grooves or tabs to prevent it from rotating once the assembly is tightened down.
The embodiments described herein are exemplary and are not meant to limit the scope of the claims as claimed below. As one skilled in the art will appreciate, many modifications and substitutions to the embodiments disclosed herein are possible without departing from the spirit of the embodiments disclosed.
This application is a continuation-in-part of U.S. patent application Ser. No. 15/462,777, filed on Mar. 17, 2017, and claims the benefit thereof.
Number | Date | Country | |
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Parent | 15462777 | Mar 2017 | US |
Child | 16746957 | US |