Reed switch and method for manufacturing the reed switch

Abstract

A novel reed switch is disclosed. The reed switch features a three-part blade, with the web portion of each blade bent relative to the conductor portion, and the bend angle is adjustable. When the blade is sealed within a glass housing, the gap between adjacent contacts of each blade does not change as the molten glass of the housing cools and hardens, ensuring reliable pull-in sensitivity of the reed switch during manufacturing. The bend between the web portion and the conductor portion may be simpler or more complex.

Description

[Technical Field]

[0001] TECHNICAL FIELD Embodiments of the present disclosure relate to reed switches, and more particularly to matters of manufacturing reed switches. [Background technology]

[0002] A reed switch is an electrical switch that is activated by an applied magnetic field. A reed switch has two ferromagnetic metal pieces, known as blades, partially enclosed in a sealed glass enclosure. Normally, the blades are not connected to each other, but they connect when a magnetic field is present. Alternatively, the blades may initially be connected to each other and then separate when brought near a magnet.

[0003] The amount of magnetic field required to activate a reed switch is known as its sensitivity, or pull-in sensitivity, and is measured in ampere-turns (AT). Ampere-turns (AT) are given by multiplying the current in the test coil by the number of turns in the test coil. There is a limited range of metal alloys suitable for reed switches, but these variations can still affect pull-in sensitivity. Mechanical characteristics of the blade, such as its length, width, and thickness of the flexible (flat) portion of the blade, can also affect pull-in sensitivity. In addition to the type, size, and shape of the blade, the distance between the tip portions of the blade, known as the contacts, affects the pull-in sensitivity of a reed switch.

[0004] Typically, reed switches have relatively thin blades with wide sections at the contacts, which give the blades some flexibility. To control the pull-in sensitivity of a reed switch, a portion of each blade is sealed in a glass housing so that the two contacts are a predefined distance apart. Reed switches can be very small. It can be difficult to manufacture a reed switch so that the two blade contacts are a precise distance apart.

[0005] It is with respect to these and other considerations that the present improvements may be useful. Summary of the Invention

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to aid in determining the scope of the claimed subject matter.

[0007] An exemplary embodiment of a reed switch according to the present disclosure may include a cylindrical housing having two ends, a first blade and a second blade. The first blade has a first conductor, a first web, and a first contact, the first web being bent at a first angle relative to the first conductor. The second blade has a second conductor, a second web, and a second contact, the second web being bent at a second angle relative to the second conductor. The first contact is adjacent to the second contact with a gap therebetween.

[0008] Another exemplary embodiment of a reed switch according to the present disclosure may include first and second blades. The first blade is inserted into a first end of a cylindrical housing and includes a first outer portion and a first inner portion. The first outer portion, located outside the housing, includes a first portion of a first conductor. The first inner portion, located inside the housing, includes a second portion of the first conductor, a first web, and a first contact. The first web is bent at a first angle relative to the first conductor. The second blade is inserted into a second end of the cylindrical housing and includes a second outer portion and a second inner portion. The second outer portion includes a first portion of a second conductor. The second inner portion includes a second portion of the second conductor, a second web, and a second contact. The second contact is adjacent to the first contact and is a predetermined distance from the first contact. The second web is bent at a second angle relative to the second conductor.

[0009] An exemplary embodiment of a method for manufacturing a reed switch according to the present disclosure may include inserting a first blade into a first end of a glass housing. The first blade has a first conductive wire, a first web, and a first contact, and the first web is bent relative to the first conductive wire. The first web and the first conductive wire are inside the glass housing, while the first conductive wire crosses an entrance to the first end. The first end is heated to seal the first blade at the first end, and the first blade is perpendicular to the first end when the first end cools and hardens. A second blade is inserted into a second end of the glass housing. The second blade has a second conductive wire, a second web, and a second contact, and the second web is bent relative to the second conductive wire. The second contact is adjacent to the first contact with a gap therebetween. The second web and the second conductor are inside the glass housing, while the second conductor crosses the entrance to the second end. The second end is heated to seal the second blade at the second end. When the second end cools and hardens, the gap remains unchanged. [Brief explanation of the drawings]

[0010] [Figure 1A] 1A and 1B show a reed switch and its housing according to the prior art. [Figure 1B] 1A and 1B show a reed switch and its housing according to the prior art. [Figure 1C] 1A and 1B show a reed switch and its housing according to the prior art. [Figure 1D] 1A and 1B show a reed switch and its housing according to the prior art.

[0011] [Figure 2A] 1 is a diagram showing the blades of a prior art reed switch. [Figure 2B] 1 is a diagram showing the blades of a prior art reed switch. [Figure 2C]1 is a diagram showing the blades of a prior art reed switch. [Figure 2D] 1 is a diagram showing the blades of a prior art reed switch.

[0012] [Figure 3] FIG. 1B illustrates pairing of blades for the reed switch of FIG. 1A according to the prior art.

[0013] [Figure 4] FIG. 1 illustrates a reed switch in accordance with an exemplary embodiment.

[0014] [Figure 5A] 5 illustrates a blade of the reed switch of FIG. 4 according to an exemplary embodiment. [Figure 5B] 5 illustrates a blade of the reed switch of FIG. 4 according to an exemplary embodiment. [Figure 5C] 5 illustrates a blade of the reed switch of FIG. 4 according to an exemplary embodiment. [Figure 5D] 5 illustrates a blade of the reed switch of FIG. 4 according to an exemplary embodiment.

[0015] [Figure 6] 5 illustrates pairing of blades for the reed switch of FIG. 4 according to an exemplary embodiment.

[0016] [Figure 7] 1 illustrates a novel reed switch blade having an alternative web design according to an exemplary embodiment. [Figure 8] 1 illustrates a novel reed switch blade having an alternative web design according to an exemplary embodiment.

[0017] [Figure 9] 5 is a graph illustrating characteristics of the reed switch of FIG. 4 in accordance with an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] A novel reed switch is disclosed. The reed switch features a three-part blade, with the web portion of each blade angled relative to the conductor portion, and the angle is adjustable. When the blades are sealed within a glass housing, the gap between adjacent contacts on each blade does not change once the glass seal is formed, ensuring reliable pull-in sensitivity of the reed switch during manufacturing.

[0019] 1A-1D are representative diagrams of a prior art reed switch 100 and its housing. FIG. 1A is a side view of the reed switch 100; FIG. 1B is a first side view of the reed switch housing perpendicular to the view of FIG. 1B; FIG. 1C is a second side view of the reed switch housing; and FIG. 1D is an isometric view of the reed switch housing. The reed switch 100 consists of a pair of blades 102a and 102b (collectively "blades 102") partially inserted into a housing 112. Further details regarding the blades 102 of the prior art reed switch 100 are provided below in the description of FIGS. 2A-2D and 3.

[0020] Housing 112 is a cylindrical tube made from glass doped with a small amount of iron to give it a light green color. The housing includes two sealed ends: sealed end 116a at one end of the cylindrical tube and a second sealed end 116b at the other end of the tube (collectively, "sealed ends 116"). FIGS. 1B-1D show housing 112 in its raw glass form before sealed end 116 is formed. Prior to becoming part of reed switch 100, housing 112 includes ends 122a and 122b (collectively, ends 122). As shown particularly in FIG. 1C, ends 122 are substantially circular, with a radius not significantly larger than the diameter of the thickest portion of blade 102. During assembly, ends 122 are heated and then cooled to harden and close around each blade 102, becoming sealed ends 116.

[0021] Each blade 102 includes an insert portion and an outer portion, named for their relationship to the housing 112. Thus, blade 102a includes an insert portion 118a and an outer portion 120a, and blade 102b includes an insert portion 118b and an outer portion 120b (hereinafter "insert portion 118 and outer portion 120"). During manufacture, while outer portion 120a remains outside of the housing 112, insert portion 118a of blade 102a is fed to end 122a, which is heated to molten glass and then sealed around the blade to form sealed end 116a. Next, while outer portion 120b remains outside of the housing 112, insert portion 118b of blade 102b is fed to end 122b, which is also heated to molten glass and then sealed around the blade to form sealed end 116b. Once these operations are complete, the insert portions 118 of the two blades are sealed, thereby preventing air, oxygen, and other gases from entering the chamber of the housing 112. An outer portion 120 of each blade 102 remains outside the housing 112 to connect the reed switch 100 into a circuit.

[0022] 2A-2D are representative diagrams of the blade 102 of the prior art reed switch 100 of FIG. 1A. The blade 102 is a unitary ferromagnetic metal element consisting of a contact 204, a web 206, and a conductor 208. FIG. 2A is a top view of the blade 102; FIG. 2B is an enlarged top view of the contact 204 of the blade 102; FIG. 2C is a side view of the blade 102; and FIG. 2D is an enlarged side view of the contact 204 of the blade 102. The blade 102 features two transitions where the properties of the blade components change. One transition is between the conductor 208 and the web 206, and the other transition is between the web 206 and the contact 204.

[0023] The conductor 208 is cylindrical in shape and therefore appears the same when viewed from the top ( FIG. 2A ) or the side ( FIG. 2C ). At one transition, the web 206 is wider than the conductor 208 in the top view, while the web 206 is thinner and flatter than the conductor 208 in the side view. At a second transition, the contact 204 is thinner and narrower than the web 206 in the top view, while the contact 204 is thicker than the web 206 in the side view. In the top view, the contact 204 resembles a flathead screwdriver. In the side view, the contact 204 resembles a small pencil with a sharp point at the end distal to the conductor 208.

[0024] The pull-in sensitivity of reed switch 100 is proportional to the gap between the two blades 102, specifically the gap between the two contacts 204 inside housing 112. Thus, the position of blade 102a relative to blade 102b determines the width of the gap. Line 110 ( FIG. 1A ) provides a reference for indicating the relative positions of blades 102a and 102b when sealed within housing 112, as well as the orientation of the housing. Blade 102b is aligned along line 110, while blade 102a is not. Instead, blade 102a is positioned above line 110. Furthermore, the top of housing 112 is offset from blade 102a by a certain amount, designated X.

[0025] The degree of offset X is unintentional. During manufacture of reed switch 100, each blade 102 is positioned so that it lies along line 110. Housing 112 is also positioned along line 110, with line 110 bisecting sealing end 116 and the top and bottom of the cylindrical housing parallel to that line. In the example of FIG. 1A , blade 102a is inserted into end 122a of housing 112 and lies along line 110. Similarly, blade 102b is inserted into end 122b of housing 112 and lies along line 110. At this point, both blades are positioned inside the yet-to-be-sealed glass housing 112, with contact 204a of blade 102a contacting contact 204b of blade 102b. A first sealing operation is performed by heating end 122a and allowing the heated glass to cool and harden, thus securing blade 102a; then a second sealing operation is performed by heating end 122b and allowing the heated glass to cool and harden, thus securing blade 102b. While the glass is still soft / molten, the gap between contacts 204 is mechanically set. After end 122 cools (becoming sealing end 116), the blades are secured. However, the mechanically set gap moves during the cooling operation, and one of the blades, in this example blade 102a, is no longer in its intended position along line 110.

[0026] Recall that the blade 102 must be sealed to the housing 112. This is accomplished by melting the edge 122 of the glass housing 112, such as by using a high-energy infrared beam. As the molten glass cools and hardens, the edge 122 becomes the sealing edge 116 that mechanically secures the blade 102. Thus, a degree of offset X occurs during the operation to secure the blade 102 to its respective sealing edge 116 of the housing 112. During the cooling and hardening phase, the two blades are "thrown" toward the center of the housing 112. This phenomenon is affected by the cohesive nature of the glass as well as gravity. Gravity pulls the molten glass toward the center of gravity of the assembly, thus affecting the initial position of the blade 102 after the gap is established. Cohesion or molecular contraction of the glass during its transition from a molten to a solid state also affects the initial position of the blade 102. Thus, the blades 102 may be positioned in their intended positions within the housing 112, while as the molten material sealing the ends cools, one (or both) of the blades shifts away from its original position.

[0027] In FIG. 1A, the housing 112 obscures the view of the blade 102, particularly the contacts 204. Therefore, a new view of the prior art blade 102 is presented in FIG. 3. Blade 102a features contact 204a, web 206a, and conductor 208a; blade 102b features contact 204b, web 206b, and conductor 208b. Blade 102b is aligned along line 110, while blade 102a is not. A gap G0 is formed between contacts 204a and 204b. Because the position of blade 102a has changed relative to its original alignment, the intended alignment of the two contacts 204 has changed. This means that the gap G0 between the two contacts 204 has varied. As a result of this variation in the gap dimension G0, the pull-in sensitivity of the reed switch 100 has varied from the original design.

[0028] Therefore, the reed switch 100 has poor performance in terms of meeting the required pull-in sensitivity (AT) set during assembly. Failure to meet the target during the manufacture of the reed switch likely results in difficulty adhering to customer demand (time and quantity). Furthermore, some inventory may have a pull-in sensitivity that is too high or too low, resulting in scrapped inventory. If additional production quantities are produced to overcome the large scrappage hit, this increases costs to the manufacturer.

[0029] 4 is a representative diagram illustrating a novel reed switch 400, according to an exemplary embodiment. Reed switch 400 consists of a pair of blades 402a and 402b (collectively "blades 402") partially inserted into a housing 412. Further details regarding blades 402 of novel reed switch 400 are provided below in the description of FIGS. 5A-5D and 6.

[0030] Housing 412 is a cylindrical tube made of glass doped with a small amount of iron to give it a light green color. In the exemplary embodiment, housing 412 is substantially similar to housing 112 of FIGS. 1B-1D. Accordingly, housing 412 includes two ends: first end 122a at one end of the cylindrical tube and second end 122b (e.g., end 122) at the other end of the tube. End 122 is substantially circular and has a radius not significantly larger than the diameter of the thickest portion of blade 402. As described in more detail below, upon receiving each blade 402, end 122 is heated to a molten material that hardens into sealed ends 416a and 416b (collectively "sealed ends 416") to secure the blade.

[0031] Each blade includes an insert portion and an outer portion, named for their relationship to the housing 412. Thus, blade 402a includes insert portion 418a and outer portion 420a, and blade 402b includes insert portion 418b and outer portion 420b (hereinafter "insert portion 418 and outer portion 420"). During manufacture, insert portion 418a of blade 402a is fed to an end (e.g., end 122a in FIG. 1D ) while outer portion 420a remains outside of housing 412, and due to the application of heat, such as a high-energy infrared beam, that end is melted into molten glass that hardens and seals around the blade. Next, insert portion 418b of blade 402b is fed to the second end (e.g., end 122b in FIG. 1D ) while outer portion 420b remains outside of housing 412, and due to the application of heat, that end is melted into molten glass, which hardens and seals around the blade. When second blade 402b is sealed, insert portions 418 of the two blades are sealed, thereby preventing air, oxygen, and other gases from entering the chamber of housing 412. Outer portion 420 of each blade 402 remains outside of housing 412 to connect reed switch 400 to a circuit.

[0032] Line 410 provides a reference for indicating the relative positions of blades 402a and 402b when sealed within housing 412, as well as the orientation of the housing. In contrast to prior art reed switch 100 (FIG. 1A), both blades 402 of novel reed switch 400 are disposed along line 410. Furthermore, in the exemplary embodiment, housing 412 is substantially parallel to line 410. There appears to be no offset between the location of the top of housing 412 and line 410, as was present in prior art reed switch 100. In the exemplary embodiment, the orientation of blade 402 and housing 412 along line 410 results from the novel configuration of blade 402.

[0033] 5A-5D are representative diagrams of blade 402 of reed switch 400 of FIG. 4, according to an exemplary embodiment. Blade 402 is a unitary ferromagnetic metal element consisting of contact 504, web 506, and conductive wire 508. FIG. 5A is a top view of blade 402; FIG. 5B is an enlarged top view of contact 504 of blade 402; FIG. 5C is a side view of blade 402; and FIG. 5D is an enlarged side view of contact 504 of blade 402. Blade 402 features two transitions where the properties of the blade components change. One transition is between conductive wire 508 and web 506, and the other transition is between web 506 and contact 504.

[0034] Conductor 508 is cylindrical in shape and therefore appears the same when viewed from the top ( FIG. 5A ) or the side ( FIG. 5C ). At one transition, web 506 is wider than conductor 508 in the top view, while web 506 is thinner and flatter than conductor 508 in the side view. At a second transition, contact 504 is thinner and narrower than web 506 in the top view, while contact 504 is thicker than web 506 in the side view. In the top view, contact 504 resembles a flathead screwdriver. In the side view, contact 504 resembles a small pencil with a sharp point at the end distal to conductor 508. In the exemplary embodiment, contact 504 and web 506 are in the same plane.

[0035] The top and enlarged top views of blade 402 (FIGS. 5A and 5B) appear substantially similar to the top and enlarged top views of blade 202 (FIGS. 2A and 2B). However, the side and enlarged side views of blade 402 (FIGS. 5C and 5D) illustrate how blade 402 differs from blade 202 (FIGS. 2C and 2D). In the exemplary embodiment, web 506 of blade 402 is bent relative to conductor 508. In the exemplary embodiment, web 506 is offset relative to conductor 508 by an angle Y°, where the angle Y° is proportional to the pull-in sensitivity of reed switch 400. In some embodiments, web 506 and contact 504 are in the same plane, so that contact 504 is also offset relative to conductor 508 by an angle Y°. Thus, novel reed switch 400 may be considered a "bent web" design. In the exemplary embodiment, angle Y is adjustable. Thus, the offset angle of the web 506 relative to the conductor 508 may be large or small depending on the desired pull-in sensitivity of the reed switch 400 .

[0036] As with other reed switches, the pull-in sensitivity of the bent web reed switch 400 is proportional to the gap between the two blades 402, specifically the gap between the two contacts 404 inside the housing 412. Thus, the position of blade 402a relative to blade 402b determines the width of the gap. In an exemplary embodiment, the Y° angle between the web 506 and the conductor 508 of the blade 402 allows for control of the gap between the two contacts 404 inside the housing 412 of the novel reed switch 400.

[0037] In FIG. 4, housing 412 obscures the view of blade 402, particularly contact 504. Therefore, a new view of blade 402 according to an exemplary embodiment is presented in FIG. 6. Blade 402a features contact 504a, web 506a, and conductor 508a; blade 402b features contact 504b, web 506b, and conductor 508b. Both blades 402a and 402b are disposed along line 510. As shown in FIG. 5C, blade 402 has web 506 offset by Y degrees from conductor 508. For the blades of the ganged reed switch of FIG. 6, web 506a of blade 402a is offset by Y1° from conductor 508a, and web 506b of blade 402b is offset by Y2° from conductor 508b. In an exemplary embodiment, offsets Y1 and Y2 are substantially similar. A gap G1 is formed between contact 504a and contact 504b, and in an exemplary embodiment, gap G1 is controlled by setting offsets Y1 and Y2.

[0038] In an exemplary embodiment, blade 402b can be created from blade 402a by flipping blade 402a vertically and then horizontally and then moving two contacts 504a and 504b until they are adjacent to one another. Alternatively, blade 402b can be flipped horizontally and then vertically before placing the contacts adjacent to one another. In the illustration of FIG. 6, web 506a of blade 402a is bent downward at angle Y1 relative to conductor 508a and line 510. Web 506b of blade 402b is bent at angle Y2 relative to conductor 508b and line 510. In an exemplary embodiment, conductor 508a lies in a plane and conductor 508b lies in the same plane. In an exemplary embodiment, reed switch 400 is non-polarized, and blades 402a and 402b are interchangeable.

[0039] 4 and 5C, the blades 402 of the bent-web reed switch 400 are inserted separately into the housing 412, similar to the blades 102 of the prior art reed switch 100. The outer portion 420a of the blade 402a consists of the conductor 508a, while the inner portion 418a consists of a portion of the conductor 508a, as well as the web 506a and the contact 504a. Similarly, the outer portion 420b of the blade 402b consists of the conductor 508b, while the inner portion 418b consists of a portion of the conductor 508b, as well as the web 506b and the contact 504b. The conductors 508 cross over into the entrances at each end of the housing 412. Thus, when the molten glass material hardens, only the conductor 508 of each blade 402 is positioned at the entrance (sealed end 416) of the housing 412.

[0040] Each blade 402 is positioned to lie along line 410. In the exemplary embodiment, electrical leads 508 are inserted into each end of housing 412 so that the electrical leads are perpendicular to sealing end 416 when the housing is sealed. Line 422a refers to the plane of sealing end 416a, and line 422b refers to the plane of sealing end 416b (collectively "lines 422"). In the exemplary embodiment, electrical leads 508 of blades 402 are perpendicular to line 422 when inserted into housing 412. Furthermore, in some embodiments, centering electrical leads 508 in sealing end 416 creates a rounded seal to improve the visual appearance of reed switch 400.

[0041] Recall that the blades 402 are to be sealed to the housing 412. This is accomplished by heating the glass material on each side of the housing until it becomes molten glass. In contrast to the blades 102 of the prior art reed switch 100, once the molten glass cools and hardens around the blades 402 at their respective sealing ends 416, neither blade 402 shifts from its original position within the housing 412.

[0042] In the exemplary embodiment, housing 412 is also positioned along line 410, bisecting sealing end 416, with the top and bottom of the cylindrical housing parallel to that line. Thus, blade 402a is inserted into the end of housing 412 and positioned along line 410 when it ends at sealing end 416a. Blade 402b is then inserted into the end of housing 412 and positioned along line 410 when it ends at sealing end 416b.

[0043] In the exemplary embodiment, the placement of the conductors 508 and the offset angles Y1 and Y2 between the webs 506 of the blade 402, respectively, cause both conductors to be attached to the housing 412 such that they are coincident with the line 410 (and perpendicular to the line 422). Furthermore, after the curing operation, when the end 416 becomes the sealed end 416, both conductors 508 remain coincident with the line 410. The reed switch 400 is still subject to gravity, which pulls the molten glass toward the center of gravity of the assembly, and cohesion or molecular contraction, which affects the housing during the transition between the molten and solid states. Nevertheless, in the exemplary embodiment, the bent web design no longer results in the blade 402 being thrown back toward the center of the housing 412 during the curing step, as occurs with the blade 102 of the prior art reed switch 100.

[0044] Because the position of each blade 402 (whether inserted first or second into housing 412) does not change relative to their original arrangement, the gap G1 between the two contacts 504 is controllable and does not vary during manufacturing. Because the dimension of gap G1 does not vary, in the exemplary embodiment, the pull-in sensitivity of reed switch 400 is maintained.

[0045] 7 and 8 are representative diagrams illustrating a novel reed switch blade having an alternative bent web design, according to an exemplary embodiment. FIG. 7 is a side view of blades 702a and 702b (collectively "blades 702") that may be inserted into a reed switch housing. Blade 702a features contact 704a, web 706a, and conductor 708a; blade 702b features contact 704b, web 706b, and conductor 708b (collectively "contact 704," "web 706," and "conductor 708"). Lines 710 are shown, as before, to indicate the relative position of each blade 702. Web 706 is characterized as having three portions: a first section 712 offset from each conductor 708 by an offset angle W1; a second section 714 parallel to the conductor; and a third section 716 offset from each conductor by an angle W2. The second blade 702b is similarly configured.

[0046] Compared to contacts 504 of blade 402 ( FIG. 6 ), in some embodiments, contacts 704 remain unchanged relative to their respective conductors 708. A gap G2 is maintained between contacts 704a and 704b during insertion of blades 702 and subsequent sealing thereof to their respective ends of the housing. By varying web 706 of each blade 702, the throwback phenomenon that characterized prior art blades 102 is avoided. Therefore, in exemplary embodiments, gap G2 is controllable using the blade design of FIG. 7 , and thus the pull-in sensitivity of reed switches featuring blades 702 is maintained during manufacturing.

[0047] 8 is a side view of blades 802a and 802b (collectively "blades 802") that may be inserted into a reed switch housing. Blade 802a features contact 804a, web 806a, and conductor 808a; blade 802b features contact 804b, web 806b, and conductor 808b (collectively "contact 804," "web 806," and "conductor 808"). Lines 810 are shown, as before, to indicate the relative position of each blade 802. Web 806 is characterized as being curved, such as crescent-shaped.

[0048] Compared to contacts 504 of blade 402 (FIG. 6), in some embodiments, contacts 804 remain unchanged in position relative to their respective conductors 808. A gap G3 is maintained between contacts 804a and 804b during insertion of blades 802 and subsequent sealing thereof to their respective ends of the housing. By varying web 806 of each blade 802, the throw-back phenomenon that characterizes prior art blades 102 is avoided. Therefore, in exemplary embodiments, gap G3 is controllable using the blade design of FIG. 8, and thus the pull-in sensitivity of reed switches featuring blades 802 is maintained during manufacturing.

[0049] The embodiments of Figures 7 and 8 are not meant to be limiting. The web of each blade may be adjusted in a variety of different ways to eliminate the throw-back phenomenon during sealing of the blade into the reed switch housing. In exemplary embodiments, whether the bent web design of Figure 6 or the alternative web designs of Figures 7 and 8, modifying the web to be "out of plane" from the blade conductors avoids the manufacturing drawbacks of prior art reed switch 100.

[0050] 9 is a fitted line plot of the flexure web reed switch 400 of FIG. 4 according to an exemplary embodiment. Graph 900 plots pull-in sensitivity versus gap distance for the reed switch 400. For the prior art reed switch 100 (FIG. 1A), the correlation between pull-in sensitivity and gap is 29% up to only 35 AT (35 A). In an exemplary embodiment, for the new reed switch 400, the correlation between pull-in sensitivity and gap is 82% up to 50 AT (50 A). This means that gap and pull-in sensitivity are approximately linear and more predictable. In some embodiments, having a consistent gap during reed switch manufacturing results in better pull-in sensitivity targeting.

[0051] In an exemplary embodiment, the bent web design of the new reed switch 400 improves the targeting of pull-in sensitivity even at 30 AT (30 A) and greater, thus ensuring that the gap between the blades remains constant during the glass-to-metal sealing process. Instead, on each end of the housing, a wire rod of electrical conductor is centered in the seal of the housing.

[0052] As used herein, elements or steps described in the singular and preceded by the word "a" or "an" should be understood as not excluding a plurality of elements or steps, unless such exclusion is expressly stated. Furthermore, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0053] While the present disclosure refers to particular embodiments, many modifications, alterations, and variations can be made to the described embodiments without departing from the sphere and scope of the disclosure as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described embodiments, but rather have its full scope defined by the language of the following claims and equivalents thereof.

Claims

1. a cylindrical housing having a first end and a second end; a first blade having a first conductor, a first web, and a first contact, wherein the first web is bent and curved at a first angle relative to the first conductor; and a second blade having a second conductor, a second web, and a second contact, wherein the second web is bent and curved at a second angle relative to the second conductor; A reed switch, wherein the first contact is adjacent to the second contact with a gap between the first contact and the second contact.

2. 2. The reed switch of claim 1, wherein said first conductor is disposed at said first end of said housing such that said first conductor is perpendicular to said first end.

3. 3. The reed switch of claim 2, wherein said second conductor is disposed at said second end of said housing such that said second conductor is perpendicular to said second end.

4. 4. The reed switch of claim 3, wherein said gap is proportional to a pull-in sensitivity of said reed switch.

5. 2. The reed switch of claim 1, wherein the first web, the first contact, the second web, and the second contact are sealed inside the housing.

6. 2. The reed switch of claim 1, wherein said first conductor lies in a plane and said second conductor lies in said plane.

7. 2. The reed switch of claim 1, wherein said first angle is equal to said second angle.

8. a first blade inserted into a first end of a cylindrical housing, the first blade comprising: a first outer portion including a first portion of the first conductor; a first blade having a first inner portion including a second portion of the first conductor, a first web, and a first contact, the first web including a first portion, a second portion, and a third portion, the first portion being offset from the first conductor by a first angle, the second portion being parallel to the first conductor, and the third portion being offset from the first conductor by a third angle; a second blade inserted into a second end of the cylindrical housing, the second blade comprising: a second outer portion including a third portion of the second conductor; a second blade having a fourth portion of the second conductor, a second web, and a second inner portion including a second contact, the second contact adjacent to the first contact with a gap between the first contact and the second contact, the second web including a fourth portion, a fifth portion, and a sixth portion, the fourth portion being offset from the second conductor by a second angle, the fifth portion being parallel to the second conductor, and the sixth portion being offset from the second conductor by a fourth angle.

9. 9. The reed switch of claim 8, wherein said first conductor lies in a plane and said second conductor lies in said plane.

10. 10. The reed switch of claim 9, wherein said first end and said second end are bisected by said plane.

11. 9. The reed switch of claim 8, wherein said first conductor is perpendicular to said first end and said second conductor is perpendicular to said second end.

12. 9. The reed switch of claim 8, wherein the gap distance is proportional to the pull-in sensitivity of the reed switch.

13. 9. The reed switch of claim 8, wherein said first angle is equal to said second angle.

14. inserting a first blade into a first end of a glass housing, the first blade having a first conductor, a first web, and a first contact, the first web being bent and curved relative to the first conductor, or the first web being bent relative to the first conductor and bent into a first section, a second section, and a third section, the first section and the third section being offset from the first conductor at a specific angle, the second section being parallel to the first conductor, the first web and the first contact being inside the glass housing, and the first conductor crossing an entrance to the first end; heating the first end to seal the first blade at the first end, the first blade being perpendicular to the first end when the first end cools and hardens; inserting a second blade into a second end of the glass housing, the second blade having a second conductor, a second web, and a second contact, the second web being bent and curved relative to the second conductor, or the second web being bent relative to the second conductor and bent into a fourth section, a fifth section, and a sixth section, the fourth section and the sixth section being offset at a specific angle from the second conductor, the fifth section being parallel to the second conductor, the second contact being adjacent to the first contact with a gap between the first contact and the second contact, the second web and the second contact being inside the glass housing, and the second conductor crossing an entrance to the second end; and heating the second end to seal the second blade at the second end, wherein when the second end cools and hardens, the gap does not change.

15. 15. The method of claim 14, wherein the second blade is perpendicular to the second end when the second end cools and hardens.

16. The method of claim 14 , wherein the first web, the first contact, the second web, and the second contact are hermetically sealed to the inside of the glass housing.

17. 15. The method of claim 14, wherein the gap distance is proportional to the pull-in sensitivity of the reed switch.

18. 10. The reed switch of claim 1, wherein said first web and said second web are crescent shaped.

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