US 3576516 A
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United States Patent 220,936 10/ l 879 McTighe inventor Leland G. Mull Vienna, Va.
Appl. No. 775,317
Filed Nov. 13, 1968 Patented Apr. 27, 1971 Assignee Radiation Systems, Incorporated McLean, Va.
QUICK CONNECT-QUICK DISCONNECT 2,355,913 8/1944 Grunebaum 339/75 2,518,464 8/1950 Guillemin, Jr. 339/151 3,416,973 12/1968 Benzinger 136/235 Primary ExaminerMarvin A. Champion Assistant Examiner-Joseph H. McGlynn Attorney-Hurvitz, Rose & Greene ABSTRACT: An electrical connector has a pair of components, one constituting a plug and the other a receptacle for the plug. The plug is a flexible sheet of insulative material of sufiicient resiliency to tend to reassume its original form after deformation, and includes a central elongated strip with pairs of tabs extending to its sides at either end thereof. Conductive leads are attached to the plug with bared portions exposed along a surface of the strip. The receptacle is a bar of insulative material of generally rectangular configuration with arms projecting from the respective corners thereof and conductive leads attached to the bar and having bared portions exposed along a surface thereof. The bared leads on plug and receptacle are positioned for electrical contact when the two members are united with the strip and the bar in overlying relation and the pairs of tabs locked at either end under the arms projecting from the bar.
PATENTED APRZT |97| m INVENTOR LELQND G. MULL.
ATTORNEYS QUICK CONNECT-QUICK DISCONNECT ELECTRICAL CONNECTOR BACKGROUND OF THE INVENTION The present invention relates generally to electrical connectors, and more particularly to a quick connect-quick disconnectconfiguration for making rapid and reliable connection between bared conductive leads.
Development of the present invention stemmed from an effort to obtain an electrical connector suitable for connecting thermocouple probe wires to the lead wires of a measuring instrument. While the ensuing disclosure will make it quite apparent that my invention is useful in many other applications of connectors, it is in this thermocouple probe connection area that particularly vexing problems arise, and in which the need for an improved connector is peculiarly apparent. Thermocouple connectors of which I am aware have been characterized by a complexity, size, and cost far outweighing any advantages they may have had. More important, the connector structure commonly involves a pin and socket configuration in which the thermocouple leads are connected to the pins by soldering or crimping, and in which the pins are typically composed of a conductive material or are coated with a conductive material (e.g., for corrosion resistance) that differs from the material of which the thermocouple leads are composed. Since thermocouple leads are purposely manufactured from suitable dissimilar metals that, upon formation of a junction therebetween, are effective to generate a voltage in response to and representative of a temperature variation from that temperature at which the junction was calibrated. it follows that the junction effects between either lead and another wire or conductive connection of dissimilar material is likely to result in the development of a voltage, however slight, in response to the thennal ambient, that introduces an error into the'temperature measurement. It need hardly be stated that a connector that creates a measurement error is totally undesirable in a measuring system requiring exceptional accuracy.
In temperature measuring instruments with which the present invention is to be used, it is frequently necessary to measure the temperature to which the thermocouple probe is SUMMARY OF THE INVENTION The electrical connector includes a molded component of insulative material in which a pair of conductive leads from an instrument to which a thennocouple is to be connected are disposed within an arcuate channel constituting the elongated bar of an H-shaped configuration. The lead ends are exposed within the channel in spaced, oppositely-directed relationship, oriented along an axis transverse to the longitudinal axis of the channel. This component forms the "receptacle of the connector.
The second component, the plug" of the connector, is a flexible sheet of insulative material in which the leads of the thennocouple are partially exposed in spaced parallel relationship along a strip constituting the strip or central portion of an l-shaped configuration. This central portion of the l corresponds generally in dimensions with those of the bar (channel) of the H, and the thermocouple leads are positioned along the strip and spaced by a distance that will place them in direct contact with respective ones of the receptacle lead ends within the channel when the two components are engaged.
In mating the two components of the connector, the tabs of the I at the top (or bottom) of the strip portion thereof are brought under the ears extending toward the top (or bottom) of the H from the bar portion thereof, to hook the two com ponents together. The strip portion of the plug is then brought into the channel of the receptacle and is bent as required to conform to the arcuate shape of the channel, the uncoupled end of the I being pulled toward the free ears 'of the H until the tabs of the former clear the ears of the latter. In performing this coupling operation, there is a sliding contact or wiping action betweenthe respective leads to be connected. When the tabs of the I are brought under free ears of the H and the strip pushed slightly in the reverse direction, there is a locking together of the two components. In practice, joining of the plug and receptacle may be accomplished very quickly, and a positive, reliable mechanical contact is established between the respective leads that assures good electrical connection. The l-shaped member is sufficiently stiff to tend to reassume its normal sheetlike or planar configuration, and in so doing, forces the leads together along the arcuate channel.
In disconnecting the plug and receptacle, a reversal of the earlier method is performed. Once the tabs at one end of the I have been released, i.e., unhooked from the ears at a respective end of the H, the plug snaps loose from the receptacle. Thus, a quick disconnect may be achieved.
Thus, it is another object of the invention to provide a lightweight, simple, quick change connector.
Still another object is to provide an extremely inexpensive connector member (plug) to which the thermocouple probe is attached, to facilitate throw-away thermocouple probes.
BRIEF DESCRIPTION OF THE DRAWINGS The above and still further objects, features, and attendant advantages of the present invention will become apparent from a consideration of the following detailed description of a preferred embodiment thereof, especially when taken'in eonjunction with the accompanying drawings, in which:
FIGS. ll, 2, and 3 are top, end and side views of a receptacle for an electrical connector according to my invention. The side view is in section, taken along the lines 3-3 of FIG. 1;
FIGS. 4 and 5 are top and side views of the plug for use with the receptacle of FIGS. 1, 2, and 3;
FIG. 6 is a perspective view of the plug and receptacle as they are being brought into mated condition as a joined connector;
FIG. 7 is a fragmentary sectional view of the receptacle taken along the lines 7-7 of FIG. 6; and
FIG. 8 is a fragmentary sectional view of the plug taken along the lines M of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT material of reasonable rigidity, such as Plexiglas, in what may be generally termed an H-shaped configuration. The side portions 10 and 11 of the H are parallel to one another and to the longitudinal axis of the receptacle, and are separated by a bar 12 of relatively wide, long, and thick proportions in terms of the usual standards that might apply to that part of an H- shaped member.
As is observed most clearly in FIG. 3, the surface 14 of bar 12 is arcuate, of generally cylindrical or convex shape, and is offset from surface 15 of each of sidemembers l0 and 11 to provide a curved channel between the two sidemembers. The other major surface of the bar, designated by reference numeral 16, is flat and has a groove 17 extending therethrough to permit access by insulated leads, which are to enter from either side of the connector and lie within the groove, to a plurality of spaced parallel holes 20 running from the floor of the groove to and through the arcuate surface M. Preferably, these holes appear at the highest point of the curve relative to the edges of bar l2, i.e., at approximately the midpoint of the convex surface (least offset from surface of the sidemembers).
Sidemembers 10 and 11 are obviously longer than bar 12, if an H-shape is to be provided, but for purposes of greater generality, since it will become apparent that a strict H is not the only suitable configuration for practicing the invention, these longer portions will also be variously referred to as extensions, arms, projections, or cars. Arms 23 and 25 of sidemembers 10 and 11, respectively, are substantially identical, but are somewhat longer than arms 24 and 26 at the opposite end of those members, for reasons which will presently be clear. Ann 24 is much wider than the other arms, making slot 28 substantially narrower than slot 30 between the arms at the opposite end.
The purpose of the narrower slot and the generally wider I and differing shape of arm 24 is to provide a means for preventing union between the two components of the connector except with a predetermined relative orientation. In other words, the configuration provides a means for keying the two connector components so that one and only one arrangement of relative positions of the two will allow them to be linked together.
In the embodiment shown in FIGS. 1, 2 and 3, four holes designated 20 are provided, the holes being arranged in pairs having relatively greater spacing than the spaces between pairs. The number of pairs of holes will, however, depend on the number of leads to be interconnected via the connector. Here, two leads 35, 36 are placed in the groove 17 from a position outside the groove (see FIG. 7), the leads being covered with suitable insulation throughout their lengths to prevent shorting upon contact therebetween, but are exposed or bared at the point where each extends through a respective corresponding hole of the two adjacent pairs of holes, the absence of insulation extending from that point to their respective shorter ends. In particular, each lead is brought through the respective hole furthest (for that pair) from the point of entry into groove 17 and laterally (relative to the longitudinal axis of the H) across the convex channel surface directly to and into the associated hole of that pair of holes. As seen in the sectional view of FIG.- 7, each bared lead may go through a complete turn of its respective pair of holes, an arrangement which provides a strong reliable mechanical bond to prevent pulling out of any or all leads from the receptacle. Additionally or alternatively, an electrically insulative cement or epoxy may be used to fill groove 17 and holes 20 to provide further protection against removal of leads. In any event, it is essential that the aligned portions 37 and 38 of the leads lying transversely in the uppermost portion of the channel formed by bar 12 be bared such that conductive connection may be established on contact. Preferably, this portion of each lead should lie flat although some bowing" as a result of the natural resiliency of a specific lead material is permissible.
Referring now to FIGS. 4 and 5 with further reference to other FIGS. as may be required for the sake of clarity, the plug 5 component of the connector, which is to mate with the receptacle component, may be characterized as of generally I- shaped configuration. The plug is preferably fabricated from flexible,'high strength sheet material, such as Mylar of about 0.0 l4 inch thickness. The I-shape is provided by a central portion 45 extending along the longitudinal axis of the plug, with tabs' or hooks 48, 49 and 50, 51 projecting to either side at respective ends of the central portion. Tab 50 projects somewhat further than any of the other three tabs, which are substantially identical, primarily because of its position at an ofl'set region 52 of the central portion 45. Slight consideration of this region will reveal that it is to cooperate with the wider slot 30 of the receptacle for the aforementioned assurance of single orientation of connector components.
Four holes are provided in spaced pairs 55 and 56, the holes generally positioned at the four comers of a rectangle, within the central portion 45 of the plug. In practice, a pair of leads 60, 61 (FIGS. 6 and 8) are woven through respective pairs 55, 56 of the holes from one end of the plug. Comparing the plug of FIGS. 4 and 5 with the receptacle of FIGS. 1, 2 and 3, the exposed or bared portion 64, 65 of each lead 60, 61 should lie along the underside of the plug as it appears in FIG. 4 in a direct line with the respective holes through which it extends. The remaining portions of the leads whether bared or insulated are insulatively cemented or epoxied'in place to the plug to provide a strong mechanical bond. The exposed lead portions are spaced by the distance between the original hole pairs 55, 56, and are parallel to each other and to the longitudinal axis of the plug.
In use of the connector, and with reference now to FIG. 6, tabs 50 and 51 ofthe plug are brought under cars 23 and 25 of the receptacle at one end, and the other end of the plug is then forced beyond the other end of the receptacle. This may be achieved because of the extended length of ears 23 and 25. In other words, as the plug is pulled or otherwise forced toward the opposite end of the receptacle, the tabs 50, 51 move toward and bottom" or abut against the surface or wall 18 (FIG. 3) of slot 30. In so doing, incidentally, the lead portions 64, 65 of the plug are drawn across (in sliding'fashion) the respective exposed lead portions 37, 38 in the channel of the receptacle. This wiping action, that occurs with each connection and disconnection of the connector components, assures that a clean, corrosion-free conductive surface is always present at each of the connector leadjunctions.
Tabs 48 and 49 are now placed under arms 24 and 26, respectively, of the receptacle, and the plug pulled back in the opposite direction, thereby locking the two connector components together. There is no danger of inadvertently disconnecting the plug and receptacle because the plug is frictionally locked in place as a result of its flexible character and its consequent assumption of the arcuate shape of the receptacle channel, and its sufficient resiliency to undergo locking of its tabs in place. In assuming that shape, the plug forces its tabs in an angular orientation relative to the slanted underside of the respective receptacle anns.
Separation of the connector components is achieved by simply pushing the plug toward the narrow slotted end of the receptacle until tabs 48, 49 are unhooked from arms 24, 26, and then pulling it back in the opposite direction. In practice, the movements by which union and separation of the connector components are achieved may be accomplished very rapidly as a result of the very simple structure of the parts and the simplicity of the method of locking and unlocking them. Accordingly, the connector has a very desirable quick connect-quick disconnect feature.
In the case where the connector is used in conjunction with a thermocouple probe, the plug is preferably the connector terminal for the thermocouple leads, which may be composed, for example, of copper and constantan, respectively. The plug is extremely inexpensive to fabricate since it may be stamped in quantity from a large sheet of Mylar, thus facilitating disposable probes for a temperature measuring instrument. The leads from the receptacle to the instrument are formed of corresponding respective materials to those of which the plug leads are formed. Hence, junction effects in the connector interfacings, which represent a significant problem in a thermocouple measurement because they tend to introduce voltage error into the measurements, are almost entirely obviated.
In a constructed embodiment, the length of the receptacle was about thirteen-sixteenths, its width was five-eighths, and its thickness five thirty-seconds; slots 28 and 30 were five-sixteenths and seven-sixteenths wide and one-eighth and onefourth deep, respectively, and the convex surface of bar 12 was offset about one thirty-second from surface 15 and had a thirteen thirty-seconds radius. The plug was twenty-nine thirty-seconds Iong,'one-half wide; the central portion 45 was twenty-one thirty-seconds long, and nine thirty-seconds wide. Each hole diameter was 0.013. All of the above dimensions are in inches.
l. Arr electrical connector, comprising:
a first H-shaped component of insulative material having an elongate bar portion of convex shape forming an arcuate channel between the side portions of the H;
spaced bare conductive leads fastened within said channel and aligned generally perpendicularly to said side portions, said leads extending through said component from another surface thereof; and
a second l-shaped component of flexible insulative material having spaced parallel leads fastened longitudinally along the central portion of said I, said leads having bared portions adapted to contact respective ones of the bared leads in said channel when said components are joined with said central portion of said I lying within saidarcuate channel of said H and with the end portions of said I hooked under the respective side portions of said H at opposite ends of said H;
whereby to establish electrical connections between respective sets of said leads on said first and second components.
2. The connector of claim 1, further including means for keying said components together in only one position of relative orientation.
3. The connector according to claim 1, wherein the convex surface of said bar portion is offset from corresponding surfaces of said side portions, and wherein said leads in said channel lie in alignment across said channel at that portion of said convex surface of least offset from said side portion surfaces.
4. The connector according to claim 3, wherein said leads of said first component are arranged to lie across respective ones 7 of said leads of said second component when said components are joined, toproduce a wiping action between the respective leads during union of said components.
5. An electrical connector, comprising:
a plug, and
a receptacle for said plug;
said plug comprising:
a flexible sheet of insulative material of sufficient resiliency to tend to reassume its original form after deformation thereof, said sheet including a central strip having a longitudinal axis, and end portions exceeding the width of said strip and oriented transverse to said longitudinal axis to form pairs of tabs at either end of said strip, and
a conductive lead attached to said strip and having a bared portion exposed thereon;
said receptacle including,
a bar portion of insulative material of generally rectangular configuration, and an ann projecting from each comer of said bar portion, and
a conductive lead attached to said bar portion and having a bare portion exposed on a surface of said bar portion;
said leads positioned for physical contact between their respective bared portions upon uniting said plug and said receptacle with said strip in overlying relationship with said bar portion and secured thereagainst by the locking of said tabs against said arms atrespective ends of said bar portion at the surface opposite said surface on which said lead is exposed on said bar portion.
6. The connector according to claim 5, wherein additional conductive leads are attached to said bar portion and to said strip, respectively, in the manner recited, to undergo physical contact, and thereby, conductive connection, when said plug and receptacle are united.
7. The connector according to claim 6, wherein the bared portions of the leads associated with said plug are oriented to be drawn across the bared portions of the leads associated with said receptacle and to form respective crossed sets therewith, when said plug and said receptacle are united.
8. The connector according to claim 7, whereinsaid surface of said bar on which said bared portions are exposed has a convex shape in the longitudinal plane.
9. The connector according to claim 8, wherein said plug and said receptacle each include cooperating means to prevent uniting thereof except in one position of relative orientation.
10. The connector according to claim 9, wherein said plug has a pair of said conductive leads, electrically connected to opposite ends of a thermocouple junction, and wherein respective leads of a pair of said conductive leads attached to said receptacle to contact said pair of thermocouple leads are composed of the same respective materials as said thermocouple leads.
11. An electrical connector, comprising:
an insulative H-shaped member having spaced exposed conductive leads secured to a surface of its central bar, and
an insulative l-shaped member having spaced exposed conductive leads secured to a surface of its center strip,
said conductive leads on one of said members positioned to conductively contact respective ones of said conductive leads on the other of said members when the end portions of said i are locked under the side portions of said H at either end of said H, and said center strip of said 1 lies across said central bar of said H with the conductive lead surfaces in confronting relation.
12. A connector for interconnecting two insulated leads,
a first insulating element for retaining lengths of bare ends of a first of said leads exposed in a common plane in a first relative orientation of said lengths,
a second insulating element for retaining lengths of bare ends of a second of said leads exposed in a common plane in another orientation, transverse to said first orientation,
said respective lengths of lead ends retained by said respective insulating elements being located relative to one another so as to cross contact internally of said insulating elements in a common plane when said first and second insulating elements are conjoined,
means for at will conjoining and separating said insulating elements,
said means including latching members arranged on said elements to engage and disengage one another upon sliding movement of said elements relative to one another only when said bare ends of said leads are in contact,
said insulating elements being discrete and wholly separable one from the other when not conjoined,
said first element being rigid and said second element being flexible,
said first element having said latching members disposed in a plane below and parallel to the plane of the bare end associated therewith, and
said second element having latching members in the plane of its associated bare end which members mate with said latching members of said first element whereby said.
second element is curved over said first element in the latched condition.
13. An electrical connector, comprising:
a plug, and
a receptacle for said plug;
said plug comprising:
a flexible sheet of insulative material of sufficient resiliency to tend to reassume its original form after deformation thereof, said sheet having a longitudinal axis along which is disposed central regions and end portions exceeding the width of said central regions transverse to said axis,
a conductive lead attached to a central region and having a bared portion exposed thereon;
said receptacle including:
a barlike member of rigid insulative material of generally rectangular configuration,
a conductive lead attached to said barlilte member and hav ing a bared portion exposed on a surface of said barlike portion,
said leads positioned for physical contact between their respective bared portions upon uniting said plug and said receptacle with said central regions in overlying relationship with said barlike member and secured thereagainst by confining said end portions at least at respective ends of said barlike member.
14. An electrical connector, comprising:
a plug, and
a receptacle for said plug;
said plug comprising:
a flexible sheet of insulative material of sufficient resiliency to tend to reassume its original form after deformation thereof, said sheet having a longitudinal axis along which is disposed central regions and end portions exceeding the width of said central regions transverse to said axis to form tabs at each end of said flexible sheet;
a pair of conductors attached to said central regions in parallel with one another and having bared portions exposed thereon;
said receptacle including:
a barlike means of rigid insulating material disposed between a pair of sidewalls,
a pair of conductors attached to said barlike means, said latter pair of conductors being in line with one another and having bared portions exposed in the plane of said barlike means between said walls,
said leads positioned for physical contact between each of the bared portions of one of said pairs and a bared portion of different ones of the other of said pairs of said conductors upon uniting said plug and said receptacle with said central regions disposed between said walls in overlying relationship with said barlike means and secured thereagainst by confining said tabs at least at respective ends of said rece, tacle.
15. An electrical connector, comprising:
a plug, and
a receptacle for said plug;
said plug comprising:
a sheet of electrical insulating material of sufficient resilience to tend to reassume its original fomi after defomtation thereof, said sheet having a longitudinal axis;
a pair of conductors attached to said sheet and having bared portions exposed on a common surface thereof;
said receptacle including:
a rigid molded bar of electrical insulating material disposed between a pair of upstanding sidewalls which are spaced to confine said sheet laterally,
a pair of conductors attached to said rigid molded bar, said latter pair of conductors having bared portions exposed on a surface of said rigid molded bar between said walls,
said leads being positioned for crossing contact one for one between each of the bared portions of one of said pairs of conductors and a bared portion of a different one of the other of said pairs of conductors upon uniting said plug and said receptacle with said sheet disposed between said walls in overlying relationship to said bar and latch means molded integral with said receptacle for securing said sheet with respect to respective ends of said receptacle to confine said sheet longitudinally against movement in at least one direction.
16. A connector for interconnecting two insulated, two-wire leads having bare lead ends, comprising:
a resinous elongated thin flexible flat plate, said plate including means for retaining both bare lead ends of a first of said two wire leads on a surface of said plate in first orientations of both said bare lead ends,
a rigid resinous receptacle wholly separable from said plate and having means for retaining both bare lead ends of a second of said two wire leads in a common plane and in orientations transverse to said first-mentioned orientations, said receptacle including integral resinous latch means, said respective lead ends being so located relative to said plate and said receptacle that said lead ends cross contact in pairs in a plane located between said plate and said receptacle when said plate and said receptacle are interlocked, I I means including said integral resinous latch means for locking said plate against lengthwise movement of said plate in one sense in said common plane with respect to said receptacle,
said receptacle including integral side rails elevated from said common plane and dimensioned and located for confining the width of said plate between said rails while said plate and device are interlocked.
17. A connector, comprising:
a thin resinous sheet having length and width,
means securing the lead ends of a first two lead wire in first spatial orientations along a surface of said sheet,
a rigid resinous receptacle having a base and upstanding sidewalls to provide a channel, said channel having approximately the width of said sheet,
means securing the lead ends of a second two lead wire along said base within said channel and in second spatial orientations transverse to said first orientations, respectively, and
means for securing said sheet flat against said base within said channel and against movement in the direction of said length in one sense and with said first-mentioned lead ends maintained crossed in one to one conductive engagement with said second-mentioned lead ends.