This disclosure relates generally to the field of electrical contact devices, and relates more particularly to an electrical contact assembly for use in electrical relays and a method for making the same.
Electrical relays are commonly employed for controllably establishing electrical connections between sources of electrical power and electrical devices. A typical electrical relay may include a power input, a power output, and a control input. Electrical current may be applied to, or removed from, the control input to selectively establish an electrical connection between the power input and the power output.
The power input and power output of a typical electrical relay are commonly embodied by electrically conductive posts or “studs” that may be connected to a source of electrical power and to an electrical device, respectively. The control input may be a simple screw terminal or the like. When an appropriate actuation current is applied to the control input, an electrically conductive contactor may be moved (e.g., via electromagnetic force) into contact with butt ends of the power input and power output that are disposed within a housing. An electrical pathway is thereby established between the source of electrical power and the electrical device.
The conductive studs that are employed for the power inputs and power outputs of electrical relays are commonly formed of silver-treated copper and are provided with silver contact pads embedded in the butt ends thereof for providing a robust electrical connection with the contactor. Conventionally, the silver pads are fastened to the butt ends of the studs via processes that involve either soldering or screwing and pressing. Such processes include numerous manufacturing steps that can be time-consuming, costly, and that can result in damage to the studs.
It is with respect to these and other considerations that the present improvements may be useful.
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 features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.
An electrical contact assembly in accordance with an exemplary embodiment of the present disclosure may include an elongate stud having a coupling end and an opposing butt end, the butt end having a recess formed therein, the recess having a head portion and a shank portion defining a shoulder at a juncture therebetween, the head portion bounded by a collar and having a diameter that is larger than a diameter of the shank portion, and a contact pad having a head and a shank, the head having a top surface and a bottom surface with a tapered sidewall extending therebetween, the shank extending from the bottom surface of the head and having a diameter that is smaller than a diameter of the bottom surface, wherein the contact pad is disposed within the recess with the bottom surface of the head disposed on the shoulder and with the collar extending over and engaging the angled sidewall of the head to retain the contact pad within the recess.
A method of forming an electrical contact assembly in accordance with an exemplary embodiment of the present disclosure may include providing an elongate stud having a coupling end and an opposing butt end, the butt end having a recess formed therein, the recess having a head portion and a shank portion defining a shoulder at a juncture therebetween, the head portion bounded by a collar and having a diameter that is larger than a diameter of the shank portion, providing a contact pad having a head and a shank, the head having a top surface and a bottom surface with a tapered sidewall extending therebetween, the shank extending from the bottom surface of the head and having a diameter that is smaller than a diameter of the bottom surface, disposing the contact pad within the recess with the bottom surface of the head disposed on the shoulder, and deforming the collar so that the collar extends over and engages the angled sidewall of the head to retain the contact pad within the recess.
An electrical contact assembly and a method of manufacturing the same in accordance with the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the electrical contact assembly and the associated method are presented. The electrical contact assembly and the associated method may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain exemplary aspects of the electrical contact assembly and the associated method to those skilled in the art.
Referring to
The assembly 10, which is shown in
The stud 12 may be an elongate, generally cylindrical member having a coupling end 16 and an opposing, butt end 18. The coupling end 16 may be adapted for coupling to a lead of an electrical power source or electrical device. In some examples, the coupling end 16 may be threaded for accommodating a nut or other removable fastener as will be appreciated by those of ordinary skill in the art. The butt end 18 of the stud 12, which may be adapted to be disposed within an electrically insulating housing of an electrical relay (not shown), may include a recess 20 for receiving and retaining the contact pad 14 as further described below. The butt end 18 may further include a base portion 21 extending radially-outwardly therefrom and defining a planar support surface 23 adjacent the recess 20. The support surface 23 may be oriented substantially perpendicular to a longitudinal axis L of the stud 12. The stud 12 may further include flanges 22a, 22b, grooves 24a, 24b, and/or other structural elements adapted for securely anchoring the assembly 10 within a housing of an electrical relay or other device. It will be appreciated that the flanges 22a, 22b and grooves 24a, 24b shown in
Referring to the cross-sectional view of the assembly 10 shown in
The recess 20 in the butt end 18 of the stud 12 may include a generally disc-shaped head portion 34 having a diameter d4 and a cylindrical shank portion 36 extending from the bottom of the head portion 34 and having a diameter d5 that is smaller than d4. The juncture of the head portion 34 and the shank portion 36 may therefore define an annular shoulder 38. The aggregate size and shape of the recess 20 may be similar to the size and shape of the contact pad 14, such that the contact pad 14 may be disposed within the recess 20 with the head 26 seated upon the shoulder 38, and with the head 26 and the shank 29 being disposed in a radially close clearance relationship with the surrounding portions of the butt end 18 (as shown in
An annular shoulder 37 may be formed in the butt end 18 of the stud 12 to define a thin annular collar 39 that surrounds the head portion 34 of the recess 20. The collar 39 may have an outer diameter d6 that is smaller than an outer diameter d7 of a relatively thicker annular sidewall 41 defined by an adjoining portion the butt end 18 that surrounds the shank portion 36 of the recess 20 and that extends between the collar 39 and the support surface 23 of the base portion 21 of the stud 12. The collar 39 may have a height h1 and the sidewall 41 may have a height h2.
A recess 57 may be formed in the tip 50 of the cylinder 42 and may be contiguous with the narrowed portion 55 of the hollow interior 46 of the cylinder 42. The recess 57 may include a cylindrical bottom portion 58 and a frusto-conical top portion 60. The top portion 60 may be defined by an annular, angled sidewall 62 extending between the narrowed portion 55 of the hollow interior 46 and the bottom portion 58 of the recess 57. In a non-limiting example, the angled sidewall 62 may be oriented at an angle in a range of 30 degrees to 60 degrees relative to a longitudinal axis of the press-fitting tool 40. The bottom portion 58 of the recess 57 may have a diameter d8 that is slightly larger (e.g., 1 millimeter larger) than the diameter d7 of the sidewall 41 of the butt end 18 of the stud 12, and may have a height h3 that is substantially equal to the height h2 of the sidewall 41. The top portion 60 of the recess 57 may have a height h4 that is substantially equal to the height h1 of the collar 39 of the stud 12.
Referring to
In step 100 of the exemplary method, the stud 12 may be formed from copper and/or other metals having good electrical conductivity. This may be accomplished via turning, rolling, and/or other conventional manufacturing methods that will be familiar to those of ordinary skill in the art, and may include forming the recess 20 in the butt end 18 of the stud 12. In step 105 of the method, the stud 12 may be treated or coated with silver and/or other metals having excellent electrical conductivity (e.g., a metal that is more expensive than, and that has electrical conductivity superior to that of, the copper or other metal from which the stud 12 is formed). In step 110 of the method, the contact pad 14 may be formed of silver and/or other metals having excellent electrical conductivity. This may be accomplished via turning, rolling, and/or other conventional manufacturing methods that will be familiar to those of ordinary skill in the art.
In step 115 of the exemplary method, the contact pad 14 may be inserted into the recess 20 in the butt end 18 of the stud 12, with the head 26 of the contact pad 14 seated upon the shoulder 38, and with the head 26 and the shank 29 disposed in a radially close clearance relationship with the surrounding portions of the butt end 18 (e.g., the collar 39 and the sidewall 41).
In step 120 of the exemplary method, the press-fitting tool 40 may be lowered onto the butt end 18 of the stud 12, with the sidewall 41 of the butt end 18 being disposed within the bottom portion 58 of the recess 57 in the tip 50 of the cylinder 42, and with the angled sidewall 62 engaging the collar 39 of the butt end 18 as shown in
It will be appreciated that the above-described assembly 10 and associated method, including fastening of the contact pad 14 to the stud 12, may be achieved without requiring any soldering, formation of threads, and/or screwing as in traditional methods for manufacturing similar electrical contact assemblies. The assembly 10 of the present disclosure may therefore be provided at a lower cost and may be manufactured more quickly than similar electrical contact assemblies manufactured using traditional methods.
As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. 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.
While the present disclosure makes reference to certain embodiments, numerous modifications, alterations and changes to the described embodiments are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claim(s). Accordingly, it is intended that the present disclosure not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.
Number | Name | Date | Kind |
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2419469 | Spiro | Apr 1947 | A |
3918625 | Nippert | Nov 1975 | A |
20050106952 | Maxwell | May 2005 | A1 |
20100159737 | Elsaesser | Jun 2010 | A1 |
Number | Date | Country |
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106463278 | Feb 2017 | CN |
7206287 | Oct 1972 | DE |
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Entry |
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European Search Report for the European Patent Application No. EP18176326, dated Nov. 7, 2018. |
Number | Date | Country | |
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20180350544 A1 | Dec 2018 | US |