US 3372887 A
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s. LADANY RETRACTABLE CORD DEVICE March 12; 1968 Filed March 23, 1965 INVENTOR SHAUL LRDHNY ATTORNEY United States Patent 3,372,887 RETRACTABLE CORE) DEVICE Shani Ladany, 431 Riverside Drive,
New York, N .Y. 10025 Filed Mar. 23, F966, Ser. No. 536,695 4 Claims. (Cl. 242--'7.13)
ABSTRACT OF THE DISCLOSURE A retractable cord device comprises a housing, a springloaded drum rotatably mounted within the housing, a cord adapted to be wound upon the drum, the drum being formed with a spiral groove for the reception of the cord. The housing is formed with a shaped orifice through which the cord passes as it is unwound from the drum, the orifice including an inwardly extending annular lip which snugly engages the cord and applies a resistance to the passage of the cord. In a modification, the mid-point of the cord is fixed to the drum and the two ends of the cord pass through a pair of adjacently-disposed orifices. A cord guide is provided between the orifices and the drum for displacing the cord ends from the perpendicular as they pass through the orifices.
The present invention relates to retractable cord devices and is particularly, but not exclusively, useful with respect to electrical cords.
An object of the invention is to provide a winding drum type of retractable cord device which is simple in construction and efiicient in operation. A further object is to provide such a device particularly useful for electrical cords in that it does not require a sliding contact arrangement for maintaining electrical continuity through the cord while the winding drum is rotated.
The various novel features of my invention are set forth with particularity in the appended claims, but will be better understood by reference to the accompanying drawings, in which FIGS. 1 and 2 are longitudinal sectional views of two forms of retractable cord devices constructed in accordance with the invention.
The device of FIG. 1 includes a cylindrical housing 2 which is preferably made of two parts held together by fasteners 4-. Disposed within the housing is a drum 6 formed with a spiral groove 8 on its peripheral surface for the reception of the electrical cord 10 adapted to be wound upon, and unwound from, the drum during the retraction and extension of the cord. The drum 6 is formed with a pair of vertical end disks or plates 12 and 14, plate 12 being journalled within a recess in housing 2, and plate 14 being journalled on a pin 16 formed with a square head 18 received in a square-opening in the housing 2 to prevent the rotation of the pin. A coil spring 20 is disposed within a recess formed at the end of drum 6 adjacent to plate 14. One end of the spring is fixed to pin 16 by being inserted within slot 17 thereof, and the other end is fixed to the drum, the spring thus storing energy upon rotation of the drum in the unwinding direction and releasing the energy to drive the drum in the winding direction. For locking the drum against rotation when the cord is extended, there may be provided a toothed wheel 22 fixed to pin 16 and a pair of pawls 24 and 26 pivotably mounted on pins 24 and 26 carried by end plate 14. Such locking means are well known and are effective to lock the drum against rotation and to release the drum when a quick snap is given to the cord, permitting it to be retracted by spring 20.
Housing 2 is formed with a shaped orifice 30 through which one end of the cord 10 (i.e. the end containing the socket 32) passes as it is unwound from the drum. Orifice 30 has a diameter substantially equal to that of cord 10 and is shaped with an inwardly extending annular lip 30 which snugly engages the cord and applies a resistance to the cord as it passes through the orifice. That is, as the cord is pulled through the orifice by the springloaded drum while being rewound onto the drum, it makes continuous frictional contact wtih the lip of the orifice, except for the very short time it is substantially perpendicular to the orifice as it passes therethrough from the drum. The resistance produced by this frictional Contact is suflicient so that the cord is placed under tension as it is retracted within the housing, and therefore will more positively seat itself within groove 8 on the drum as it is retracted. When the cord has completed one layer of windings on the drum, the windings themselves form a spiral groove upon which the second layer of windings will form, and so on until the complete cord is wound upon the drum.
The opposite end of the cord 10 is fixed to the housing by fastener 34 and terminates in an electrical plug 36.
Drum 6 is formed with a cylindrical cavity 40 in which is disposed a span 10 of the cord between its plug 36 (Le. the fixed end) and the first winding on drum 6. The end of span 10' opposite to the plug end passes through a bore 42 in the drum to its peripheral surface and is fixed by a fastener 43. Span 10 is given a preformed spiral in the direction opposite to the unwinding direction of the drum. In this manner, even though one end of the cord is fixed the drum may be rotated for extending or retracting the opposite end of the cord without the need of a sliding contact arrangement between the cord ends. By giving the span a spiral in the direction opposite to the unwinding direction of the drum, the drum may be rotated a large number of rotations before the span of the cord becomes taut.
FIG. 2 illustrates another device constructed in accordance with the invention. In this device, the need of sliding contacts is avoided by having both ends of the cord wound and unwound from the drum 106. For this purpose, housing 102 includes a pair of shaped orifices and 131, both similar to orifice 30, through which orifices the socket end 132 and the plug end 136 of the cord pass as the two ends are simultaneously Withdrawn from the device. The peripheral surface of drum 106 is formed with a pair of spiral grooves 108 and 109 which receive the two ends of the cord as they are wound upon the drum. The mid-point of the cord is fixed to the drum by a fastener 111. The remaining structure of the drum, particularly its end plates, spring, and locking elements, may all be the same as in the FIG. 1 embodiment.
In FIG. 2, there is also provided a cord guide disposed between the shaped orifices and the drum. The cord guide displaces from the perpendicular the exit angle of the cord as it passes through its orifice, thereby increasing the resistance and tension of the cord during its retraction. Actually, in FIG. 2 there are two such cord guides, one for each of the two ends of the cord wound and unwound from the drum. The cord guides in the FIG. 2 embodiment are constituted by a pair of openings and 152 in a plate or partition 154- formed by the housing between the drum 106 and the shaped orifices 130 and 131. The openings 150 and 152 are disposed so that they displace their respective ends of the cord from the perpendicular as these ends pass through orifices 130 and 131. The resistance on the ends of the cord is thereby increased, and therefore the cord will more positively seat within the grooves 108 and 109 as the cord is retracted by the drum spring.
A similar type of cord guide could of course also be provided in the FIG. 1 design.
It is thus seen that in both embodiments, an even tension is applied to the cord as it rewinds itself upon the drum thus assuring that it will rewind properly. Also,
there is no necessity for the provision of sliding contacts, such as slip rings or the like, since in FIG. 1 the span 10 within the cavity in drum 6 permits the rotation of the drum even though one end of the cord is fixed, and in FIG. 2, both ends of the cord are unwound and wound at the same time.
Many changes, variations and applications of the illustrated embodiments may be made within the scope of the invention as defined in the following claims.
1. A retractable cord device comprising a housing, a drum rotatably mounted within said housing, a cord adapted to be wound upon and unwound from said drum for retracting and extending the cord, said drum being formed with a spiral groove for the reception of said cord when wound thereupon and spring means adapted to store energy upon rotation of the drum in the unwinding direction and to release energy to drive the drum in the winding direction, said housing being formed with an orifice through which one end of the cord passes as it is unwound from the drum, said orifice having a diameter substantially equal to that of the cord and being shaped with an inwardly extending annular lip which snugly engages the cord and applies a resistance to the passage of the cord therethrough so that the cord is placed under tension as it is retracted within the housing and wound onto the spiral groove of said drum.
2. A device as defined in claim 1, wherein said housing includes a pair of said shaped orifices formed adjacent to each other, the cord being fixed at its mid-point to said drum, and both ends of the cord being wound upon and unwound from said drum at the same time and passing lthrough said pair of shaped orifices as said cord is retracted and extended.
3. A device as defined in claim 2, wherein said housing includes a cord guide disposed between said shaped orifices and drum, said cord guide displacing from the perpendicular the exit angle of both ends of the cord as they pass through the orifices thereby increasing the said resistance and tension of the cord.
4. A device as defined in claim 1, wherein the opposite end of said cord is fixed to said housing and wherein said drum is formed with an internal cavity and with a bore communicating same with the peripheral surface of the drum, a spiralled span of the cord at said opposite end being disposed within said cavity and extending through said bore to the peripheral surface of said drum, permitting the drum to be rotated for extending or retracting said one end of the cord while said opposite end is fixed to said housing.
References Cited UNITED STATES PATENTS 416,255 12/1889 Cortlell 242-107.1l 1,455,715 5/1923 Danese 242-107.l2 2,572,856 10/1951 Hallberg 242107 3,061,234 10/1962 Morey 242-107.1 3,144,218 8/1964 Tepe 242-1071 3,260,472 7/1966 Zolot 242107.12
FOREIGN PATENTS 42,863 8/1930 Denmark. 822,381 11/1951 Germany.
WILLIAM S. BURDEN, Primary Examiner.