US 3830538 A
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United States Patent [191 Moberg I [451 Aug. 20, 1974 SEAL  Inventor: Sigurd M. Moberg, Orange, NJ.
 Assignee: E. J. Brooks Company, Newark,
 Filed: June 1, 1972  Appl. No.: 258,608
 US. Cl. 292/322  Int. Cl. G09f 3/00  Field of Search 292/307, 318, 320, 321,
292/322; 24/16 PB, 30.5 PB, 208.3
 References Cited UNITED STATES PATENTS 2,372,811 4/1945 Conaway et al. 292/322 X 3,368,247 2/1968 Orban 24/16 PB 3,402,435 9/1968 Merser 292/322 X 3,467,427 9/1969 Moberg 292/322 3,597,803 8/1971 Van Neil t 24/16 PB 3,600,027 8/1971 Noland 292/322 Primary Examiner-Richard E. Moore Attorney, Agent, or FirmRobert E. Ross  ABSTRACT A seal formed of molded resilient plastic material, including a housing through which a shackle is passed, said housing having internal integral shackle engaging fingers. The shackle is provided with annular shoulders for engagement by the fingers so that the shackle can be drawn through the housing in one direction, but is prevented from retrograde movement. The end portion of the shackle is provided with annular enlarged portions which may be drawn through the housing without excessive pulling force being required, yet provides a surface providing for gripping by the fingers. A portion of the shackle between two adjacent annular shoulders is provided with a weakened portion to insure that when sufficient tension is applied, the shackle will fracture at that position, with said position being predetermined for the application in which the seal is to be used, so that the fracture occurs within the housing.
2 Claims, 5 Drawing Figures SEAL BACKGROUND OF THE INVENTION US. Pat. No. 3,467,427 discloses a seal having a housing with a passage therethrough for receiving a shackle. The shackle has a plurality of rearwardly facing shoulders which cooperate with resilient fingers within the housing to allow the shackle to be drawn through the housing but to prevent retrograde movement of the shackle.
SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS In the drawing:
FIG. 1 is a top plan view of a seal embodying the features of the invention;
FIG. 2 is a view in side elevation of the seal of FIG.
FIG. 3 is a top plan view, partly in section, of the seal of FIGS. 1 and 2 assembled with a closure mechanism;
FIG. 4 is a view in section taken on line 4-4 of FIG.
FIG. 5 is a view similar to FIG. 3 after the shackle of the seal has been tightened and the end broken off.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring to the drawing, there is illustrated a seal 10, which is adapted for assembly with a closure mechanism 12 to indicate whether said mechanism has been opened by unauthorized personnel. Although the presence of the seal will not prevent the opening of the mechanism and pilferage of the contents, it will provide evidence of the removal of the contents, since the closure member cannot be opened without rupturing the seal.
The seal is preferably formed of a single piece of molded plastic such as polyethylene or polypropylene, and comprises a housing 14 and a shackle 16 for insertion into the housing to form a loop for extending through suitable apertures 18 and 20 in the operating portions of the closure member.
The housing 14 is formed of a relatively thick wall section 26 and a thinner wall section 28 extending upwardly therefrom, terminating in a restricted neck 30. An aperture 32 extends through the housing to receive the shackle, and to retain the shackle locked in the housing, a series of resilient fingers 34 extend upwardly and inwardly from the thick wall section 18.
The shackle 16 is provided with a plurality of annular locking portions each of which comprises a forward camming surface 36 leading to a rearwardly facing shoulder 38. The remote end portion of the shackle is provided with annular bulges 40 for a purpose to appear hereinafter.
To insure that the shackle will break at the desired point, an annular goove 42 is provided in the shackle between a predetermined pair of annular locking portions.
In the particular embodiment of the invention, the seal is designed for use with a closure assembly of a par ticular size so that the circumferential distance to be enclosed by the seal is known, and the groove 42 is disposed at a position on the shackle which will be within the housing when the seal is tightened around the two portions 22 and 24 of the closure assembly.
To assemble the seal, the shackle is inserted through the apertures 18 and 20, inserted into the bottom of the housing, and pushed through the housing far enough that the end portion can be grasped by the fingers at the top of the housing. Thereafter the shackle is pulled through the housing until it tightens around the portions 22 and 24, at which point the groove 42 is positioned inside the housing. As the shackle locking element passes through the housing, the fingers 26 flex outwardly on each camming surface 28 and snap inwardly behind each shoulder 30 as it passes. When the groove 42 is positioned inside the housing, further tension applied to the shackle causes it to rupture at the groove 34, and the fingers 26 seat behind the shoulder 30 of the adjacent locking portion, preventing retraction of the shackle. Thereafter no portion of the shackle protrudes from the housing, which might assist in unlocking the seal without destruction or evidence of tampering.
The bulges 40 on the end of the shackle provide sufficient friction when gripped by the fingers to allow adequate tension to be applied to the shackle to accomplish both the tightening of the shackle and the rupturing at the groove 42, yet do not provide appreciable resistance to insertion through the housing.
In the illustrated embodiment a plurality of locking elements are illustrated, although in a particular application only the one adjacent the groove 42 is required. However, in the manufacture of plastic molding dies, it is relatively economical to have one set of dies with a plurality of locking elements and a die insert to form the groove 34, which insert may be positioned between any desired pair of locking elements, as established by the length of the shackle loop required to encircle the object to which the seal is to be applied. However, in the case of an application in which the seal is to be used in very high volume, it may be economical to build a special set of dies, in which case only one locking element would be required.
Since certain obvious changes may be made in the illustrated device without departing from the scope of the invention, it is intended that all matter contained herein be interpreted in an illustrative and not a limiting sense.
1. A seal, comprising a housing and a shackle attached at one end to the housing, and having a series of locking elements disposed thereon with one portion disposed between a predetermined pair of adjacent locking elements having a cross-sectional area less than that of any other portion of the shackle, said housing having an aperture extending therethrough and resilient means in the aperture permitting movement of the locking elements therethrough in one direction but preventing retrograde movement, said one portion being so positioned on the shackle that when the seal it tightspaced longitudinally rounded enlarged portions having an overall diameter less that that of the locking elements which allow said remote end to be pushed through the housing without excessive resistance, but provide sufficient friction when gripped by the fingers to enable the locking portions to be pullsed through the housing.