US2756403A

US2756403A - Combined cord connector and strain relief

Info

Publication number: US2756403A
Application number: US508082A
Authority: US
Inventors: Wallace R Francis; George C Mapelsden; Herbert D Williams
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1955-05-13
Filing date: 1955-05-13
Publication date: 1956-07-24
Anticipated expiration: 1973-07-24

Description

July 24, 1956 w. R. FRANCIS ET AL 2,756,403

COMBINED CORD CONNECTOR AND STRAIN RELIEF Filed May 15, 1955 [)7 venors: George C. Mape/saen, Herberfl M/flm s, Wa//ace R Franc/s,

Qg W1. find/Mi The/r- Az: Cor/763g.

nited States Patent t COMBINED CORD CONNECTOR AND STRAIN RELIEF Wallace R. Francis, Milford, George C. Mapelsden,

Easton, and Herbert D. Williams, Monroe, Conn., assignors to General Electric Company, a corporation of New York Application May 13, 1955, Serial No. 508,082

9 Claims. (Cl. 339-128) The present invention relates to electrical connectors and particularly to combined electrical cord connectors and strain reliefs for use with electrical equipment and appliances.

This invention is particularly useful in the power supply cords for television receivers although it will be readily appreciated that it is not limited to such a use, and that it is readily adaptable to resilient bushings and grommets as well as electrical connectors. At the present time, the connectors for such appliance cords are adapted to be attached by means of permanent fasteners such as rivets to the removable back panel of the television set. Thus, when it is necessary to repair the set, the removal of the back panel will automatically disconnect the set from the power source so as to reduce the likelihood of high voltage shocks being received by the Serviceman.

The present invention was conceived in order to eliminate the above-mentioned rivets and the consequent labor costs by making it possible to readily snap the connector of the cord into an opening in the back panel so that the connector would be able to withstand pulling forces in the order of 35 pounds while making it difiicult to remove with the hands without the use of special tools.

The principal object of this invention is to provide a combined connector and strain relief for an electrical cord so that it may readily be mounted in a non-circular opening in a thin panel member.

A further object of this invention is to provide a combined connector and strain relief for an electrical cord which is relatively easy to insert in an opening in a panel member while being difiicult to remove without the exertion of a large force which would tend to damage the cord or connector rather than remove it.

A further object of this invention is to provide a combined connector and strain relief for an electrical cord having a recessed tapered portion which may be satisfactorily inserted in a non-circular opening in a thin panel member.

Our invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Figure 1 is a top plan view of a combined connector and strain relief embodying our invention.

Figure 2 is a cross-sectional view taken on the lines 22 of Figure 1.

Figure 3 is a cross-sectional view taken on the lines 3-3 of Figure 1.

Figure 4 is a side elevational view of the combined connector and strain relief of Figure 1.

Figure 5 is a right-hand end view of the combined connector and strain relief of Figure 4.

Figure 6 is a left end view of the combined connector and strain relief of Figure 4 taken on a plane through the electrical cord.

Figure 7 is a perspective view of the combined connector and strain relief of Figure I mounted in a rectangular-shaped opening in a thin panel member.

2,756,403 Patented July 24, 1956 Figure 8 is a top plan view similar to Figure 1 showing a second modification of this invention.

Figure 9 is a side elevatioual view similar to Figure 4 showing the species of Figure 8.

Figure 10 is a top plan view of a combined connector and strain relief similar to Figure 1 showing a third modification of our invention.

Figure 11 is a right end elevational view of the combined connector and strain relief of Figure 10.

Figure 12 is a side elevational view of the combined connector and strain relief of Figure 10.

Referring in detail to the drawing in which like elements are represented by the same reference numerals, Figure 1 shows a combined connector and strain relief 10 formed of rubber or similar elastomeric material secured on the end of an electrical cord 11. While the connector 10 i shown as having recessed contacts 12, it is clear that the connector could as an alternative be provided with male prongs without departing from the scope of this invention. The contacts 12 are crimped, soldered or otherwise fastened to the conductors 22 of the cord 11, and the body of connector 10 of suitable vinyl or elastomeric material having resilient characteristics is molded thereover. The connector 10 is provided with a shoulder portion 13 at one end, an annular recessed tapered or beveled portion 14 and a series of transversely-spaced longitudinally-extending ribs or ears 15 arranged around the connector body and adjacent the smallest end of the tapered portion to be opposed to the shoulder 13. Each ear 15 has a sloping outer surface that is inclined generally in the same direction as the recessed tapered portion 14. This does not mean that these surfaces are necessarily parallel to each other but rather that they are not opposed to each other. As best seen in the cross-sectional view of Figure 2, the ears 15 have undercut sides 16 which reduce the width of the base of the ear as it approaches the tapered section 14. Also, the pair of recesses 17 which separate the ears 15 on the top and bottom of the connector have a depressed fioor 18 as best seen in Figure 3. Thus, each car 15 may be readily deformed so that it will flow sidewise as well as lengthwise into the tapered section 14. The connector 10 is designed to be secured in a rectangular-shaped opening 19 in a thin panel member such as panel 20 of Figure 7. The dimensions of the opening 19 are slightly less than the corresponding dimensions at the large end of the tapered section 14, as i shown with dotted lines 19' in Figure 1, to provide a snug fit after assembly.

Since the connector 10 is larger in over-all size than the opening 19 in the panel member 20, it is necessary to provide an access slot 21 in the side edge of the panel member 20 so that the cord 11 may be fed through the slot 21 into the opening 19 with the connector 10 located adjacent the side of the panel not visible in Figure 7. Then a pulling force is applied to the cord 11 so that the peripheral edge of the opening 19 will obstruct the free movement of the ears 15 through the opening. When the pulling force is continued, the ears 15 will be depressed by flowing into the tapered section 14 as Well as sidewise into the recesses separating the ears. As the shoulder portion 13 bears against the edges of the opening 19, the cars 15 will spring outwardly from the opening to be in the position as shown in Figure 7. The thickness of the panel 20 is made equal to or slightly greater than the width of the tapered section 14 in an attempt to eliminate all free movement between the connector and the panel. Accordingly, it can be seen that the ears 15 are of novel design to cooperate with the tapered section 14 to make it relatively easy to insert the connector in the panel 20 while all pulling forces tending to remove the connector from the panel are resisted by the strong shoulder portion 13 which is able to support more than 35 pounds of force applied to the cord.

In the second species of Figure 8, there is a combined connector and strain relief molded on the end of an electrical cord 11 in a similar manner as is shown in Figure l. The connector 30 has a shoulder portion 33 as well as a recessed tapered section 34. and a series of longitudinally extending ears 35. The shoulder portion 33 is similar to the shoulder 13 of Figure l, and the same is also true of the

tapered sections

34 and 14. However, the ears 35 are a modification of the cars 15 of Figure 1. Each ear 35 is provided with an overlying tip 36 which extends over a portion of the tapered section 34. The side walls of the ears 35' are not undercut as at 16 nor are the recesses 37 provided with an undercut door as at 13 in Figure 3. The principal purpose of the tips 36 of the ears 35 is' to provide the connector 39 with a strong gripping action for engaging the edges of the opening 19 in the panel 20. However, the ears 35 would not be quite as readily deformed as the undercut ears 15 of the species of Figure l.

The two species of Figures 1 and 8 may be termed pullin connectors for they are assembled in the panel by exerting a pulling force on the cord. The third species of Figure 10 is somewhat different in that it is pushed into the opening in the panel; therefore, it may rightly be classified as a push-in type connector. This third connector 40 is similarly of resilient insulating material that is molded on the end of the cord 11. The shoulder portion 43 is here adjacent the transverse centerline of the connector, while the longitudinally extending cars are arranged on the free end of the connector to be compressed or deformed when a pushing force is applied to the connector 40 until the tapered section 44 is located within the opening 19 of the panel member 29. Since the connector 40 may be pushed into the opening in the panel member, the access slot 21 may be eliminated. A slight disadvantage of this design is that the series of ears 45 must also resist the pulling forces applied to the conductor 11 in the same manner as the

shoulder portions

33 and 13 in the other two species. Accordingly, the connector 40 is not designed for the same rugged use as species one and two since it is not able to support as great a pulling force as the

shoulder portions

13 and 33 of Figures 1 and 8 respectively, The ears 45 are not undercut as at 16 in Figure 2 nor are the recesses 47 depressed as at 18 of Figure 3 since the ears must by themselves support all of the pulling force's transmitted through the cord 11.

In the species of Figure l, the cars 15 are more readily deformed than either the

ears

35 or 45. Also, the shoulder portion 13 is able to' resist a pulling force greater than that of cars 15 while equal to the resistance provided by shoulder portion 33 of Figure 8. Thus, the species of Figure l is the preferred embodiment of our invention.

Accordingly, having described our invention of a combined cord connector and strain relief, it should be readily understood by those skilled in this art that we have provided a reliable strain relief means for the connector so that it may be easily attached in an opening in the panel member and cannot be removed by the hands without the use of special tools. While we have chosen to illustrate our invention in connection with a connector having recessed contacts, it will be readily apparent that this strain relief means may be incorporated in resilient bushings that are to be attached to panel members and that it has found its greatest use with bodies that are to be inserted in non-circular openings in a panel member. The resulting structure is of r'elativelysimple design which is easy to mold in mass production quantities but the greatest advantages are enjoyed by the manufacturer who Will purchase a cord set having a connector embodying our invention because of the ease of assembling the connector without the use of permanent fasteners.

Modifications of this invention will occur to those skilled in this art and it is to be understood, therefore, that this invention is not limited to the particular embodiments disclosed but is intended to cover all modifications which are within the true spirit and scope of this invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electrical cord having a combined cord connector andstrain relief secured thereto, comprising a body of resilient material with a generally rectangular transverse cross-section, a recessed tapered portion symmetrically arranged at least on the top and bottom of the body, there being a shoulder portion at the large end of the tapered portions, and a plurality of transversely spaced longitudinally extending cars at least on the top and bottom of the body adjacent the small end of the recessed tapered portions, the backs of the said ears being inclined in the same direction as the angle of the related tapered portion.

2. An electrical cord having a combined cord connector and strain relief secured thereto, comprising a body of resilient material with a generally rectangular transverse cross-section, a continuous recessed tapered portion extending around the body, there being a shoulder portion on opposite sides of the body at the large end of the tapered portion, and a series of transversely spaced longitudinally extending ears on opposite sides of the body adjacent the small end of the tapered recess, the backs of the said ears being inclined in the same direction and substantially at the same angle as that of the recessed tapered portion.

3. In combination with a thin panel having an opening therethr'ough, an electrical cord having a combined connector and strain relief secured thereto, comprising a body of resilient material having a generally rectangular transverse cross-section with a recessed tapered portion extending around the body, a shoulder portion symmetrically arranged adjacent the large end of the recessed tapered portion, and a series of transversely spaced longitudinally extending ears symmetrically arranged adjacent the small end of the recessed tapered portion, the backs of the said ears being inclined in the same direction and substantially at the same angle as that of the recessed tapered portion, while the size and shape of the large end of the tapered portion are substantially equal to that of the opening in the said panel so that the body will be scarcely embraced therein.

4'. A body member as recited in claim 3 wherein the tips of said ears overlie a section of the said tapered portioii so as to provide a strong gripping force to hold the body member in the opening in a panel and prevent the swiveling movement of the body member with respect to the panel.

5. An electrical cord having a combined cord connector and strain relief secured thereto, comprising a body of resilient material with a generally rectangular transverse cros's-section, a recessed tapered portion, symmetrically arranged at least on the top and bottom of the body, there being a shoulder portion at the large end of the tapered portion, and a plurality of transversely spaced longitudinally extending ears at least on the top and bottom of the body adjacent the small end of the recessed tapered portion, the backs of the said ears being inclined in a converging manner in a direction away from the tapered portion.

6. In combination with a thin panel having an opening therethrough, a body member of resilient material that is adapted to be fastened in the panel opening, said body having a generally rectangular transverse crosssection with a recessed tapered portion extending around the body, a shoulder portion symmetrically arranged adjacent the large end of the recessed tapered portion, and a series of transversely spaced longitudinally extending ears symmetrically arranged adjacent the small end of the recessed tapered portion, the backs of the said ears being inclined in the same direction and substantially at the same angle as that of the recessed tapered portion, while the size and shape of the large end of the tapered portion are substantially equal to that of the opening in the said panel so that the body will be securely embraced therein.

7. In a body member of resilient material that is adapted to be fastened in an opening in a panel member, a recessed tapered portion located between a shoulder on one side and a series of longitudinally extending ears on the other side adjacent the smallest end of the tapered portion, the backs of the said ears being inclined in the same direction and substantially at the same angle as that of the recessed tapered portion, while the said ears have undercut sides to reduce the width of the ears at the base of each so as to facilitate the easy insertion of the body member into an opening in a panel.

8. An electrical cord having a combined connector and strain relief of resilient material secured thereon, said connector comprising a body having a shoulder portion at one end in cooperation with an annular recessed tapered portion adjacent thereto, and a series of longitudinally-extending transversely-spaced deformable ears having their end portions aligned with the other side of the tapered portion, the smallest end of the tapered portion being adjacent the said ears, the back surface of each of the said ears being inclined in generally the same direction as the tapered portion, the ears having undercut sides to reduce the width of the ears at the base thereof while the spaces between some of the adjacent ears have a depressed floor so as to facilitate the easy insertion of the connector into an opening in a thin panel member whereby the panel would be clamped between the said shoulder portion and the ears.

9. An electrical cord having a combined cord connector and strain relief secured thereto comprising a body of resilient material with a generally rectangular transverse cross-section, and a series of transversely spaced longitudinally extending ears extending around one end of the body, an annular recessed tapered portion with its smaller end adjacent the said series of ears, and a shoulder portion bordering on the other side of the annular tapered portion which is thus located between the said ears and shoulder, the backs of said ears being inclined in the same direction and substantially at the same angle as the taper of the recessed portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,287,285 Garnrneter Dec. 10, 1918 1,577,539 Polk Mar. 23, 1926 1,601,255 Marra Sept. 28, 1926 2,115,495 Mapelsden Apr. 26, 1938 2,196,785 Takigucki Apr. 9, 1940 2,421,456 Judisch June 3, 1947 2,441,907 Schrnitt May 18, 1948 2,494,814 Huth Jan. 17, 1950 2,668,316 Sturtevant et al Feb. 9, 1954 2,697,817 Fratila Dec. 21, 1954 2,704,355 Holton Mar. 14, 1955 2,711,522 Goodwin June 21, 1955