US3717369A

US3717369A - Plastic seal with hinge

Info

Publication number: US3717369A
Application number: US00089543A
Authority: US
Inventors: J Stoffel; C Fuehrer
Original assignee: Stoffel Seals Corp
Current assignee: Stoffel Seals Corp
Priority date: 1970-11-16
Filing date: 1970-11-16
Publication date: 1973-02-20
Anticipated expiration: 1990-02-20
Also published as: IT941157B; FR2114720A5; GB1373248A; CH525814A; DE2156679A1; CA947048A

Abstract

An all plastic seal in which a strap provided with a locking head is connected to the seal body by way of a hinge structure.

Description

United States Patent 1 Stoffel et al. 1 Feb. 20, 1973 [54] PLASTIC SEAL WITH HINGE [56] References Cited UNITED STATES PATENTS Inventors: John F. Stone, Yonkers; Charles 3,146,012 8/1964 King ..292/32O Fuehrer Scarsdale both ofN Y 3,466,077 9/1969 Moberg ..292/322 3,402,435 9/1968 Merser ..24/1 6 [73] Assignee: Stoffel Seals Corporation, New 3,367,701 2/1968 Werk ...292/32l YOIk, N.Y. 3,467,427 9/1969 Moberg ..292/322 22 Filed: Nov. 16, 1970 D Primary ExammerRobert L. Wolfe pp 89,543 Attorney-Craig & Antonelli [57] ABSTRACT [52] [1.8. C1 ..292/32l, 70/322 An all plastic eal in which a strap provided with a [51] Int. C1. 865d 55/06 locking head is connected to the sea] body by way of a [58] Field 01 Search ..292/318, 319, 320, 321, 307,

292/322, 330; 24/16 PB, 150 PP, 30.5 PB; 70/41 hinge structure.

19 Claims, 9 Drawing Figures PATENTED FEBZOIHTS SHEET 10F 2 FIG. IA

INVEHTO'RS CHARLES FUH 3 JOHN F STOFFEL ATTORNEYS PATENTED 3,717, 36 9 SHEET 2 OF 2 ATTORNEYS PLASTIC SEAL WITH HINGE The present invention relates to a plastic seal, and more particularly, to an all plastic self-locking seal with a hinged tie-member.

Various types of plastic padlock and hasp seals are known in the prior art, as exemplified, by US. Pat. Nos. 3,146,012, 3,367,701, 3,373,033, and 3,402,435. However, all of these patents entail the drawback that the use of both hands is required to close the seal as the flexible tie-member has substantially no guidance in the place containing the body inclusive the axis of the locking socket as well as the place of connection between the flexible tie-member and the body of the seal.

The present invention is concerned with eliminating this drawback and aims at providing a seal of the type described above which can be readily closed and locked by the use of a single hand. This is particularly important in connection with high-speed production lines where ease of handling and locking of the seal is of prime consideration as regards the attainable production line speed.

Accordingly, the present invention essentially consists in that the all-plastic seal is provided with a hingelike structure that keeps the tie-member .or strap together with its head in alignment with the opening in the locking socket while at the same time ensuring a simple closing of the seal by a mere pivoting movement of the tie-member about the effective pivot axis.

The hinge-like effect is attained according to the present invention by the particular structure of the plastic material, which provides guidance of the tiemember in the plane of its closing movement and forms in effect a pivot axis by a groove provided in the enlargement. Additionally, the hinge-like effect is enhanced by the particular shape and cross-section of the tie-member which imparts substantial rigidity thereto in the plane of its pivot movements, i.e., though of a certain flexibility is substantially stiff against any bending in a direction perpendicular to such a plane. Such an arrangement offers the additional advantage that it requires only a single manufacturing step, i.e., the step of molding since the seal together with the hinge structure and all other parts of the seal are made from the same material and can be formed during the same molding operation.

Another problem with seals of the type described above frequently encountered is the problem of rendering the same substantially tamper-proof, i.e., clearly indicate when the seal has been tampered with by an unauthorized person. Various locking structures intended to improve the tamper-proof characteristics of a seal have been proposed heretofore. However, all of these prior art seals entail certain disadvantages as regards security and ease of manufacture and costs involved.

One prior art construction of a fastening device of this type (U.S. Pat. No. 3,402,435) consists of a filament, adapted to be attached to a tag, which is provided with a slotted socket forming fingers to receive the head at the end of the filament. However, the socket of this prior art construction is exposed so that the fingers can be easily spread to enable removal of the head. To enhance its tamper-proof characteristics, this prior art construction not only proposes a reduced diameter neck directly behind the head, but also proposes an increase in brittleness at the neck, thereby requiring an additional annealing step in its manufacture. However, the ease of removal of the head by spreading the fingers defeats the additional safety measures of this prior art construction, apart from its increased manufacturing cost due to the required annealing operation.

Another prior art construction (U.S. Pat. No. 3,455,077) proposes to completely enclose the finger portions of the socket within a housing surrounding the socket to render such a seal more tamper-proof. In this prior art construction one housing end is completely closed. Since plastic seals of this type are massproduced, the additional step involved in closing the end of the housing inthis prior art construction directly and substantially affects the cost thereof.

Other types of plastic seal constructions are also known in the prior art. In one such prior art construction (U.S. Pat. No. 3,146,012) the interlocking slotted housing is not only relatively complicated, but is far from being tamper-proof since access can be had to the interlocking parts by way of the openings thereof. In another such prior art construction (U.S. Pat. No. 3,367,701) the tines of the engaging members are readily accessible from the open end of the socket, not to mention the fact that the interlocking parts are relatively complicated in design.

Consequently, the present invention has at an additional purpose to eliminate the aforementioned shortcomings and drawbacks encountered in the prior art and to provide an all-plastic seal which is substantially more tamper-proof yet is simple in construction as well as easy to manufacture.

The self-locking seal of the present invention includes a housing accommodating the locking socket which is of such dimensions and construction that the interlocking parts cannot be reached by items in the normal possession of a person, such as a pencil, ball point pen, or the like, which could be used to reopen the interlocking parts by inserting, for example, the end of a small mechanical pencil into the open end of the socket housing and gradually prying open the socket fingers as the head portion is wiggled back and forth, ultimately permitting its withdrawal out of the socket. To that effect the housing surrounding the locking sockets has such a ratio of length to diameter of its bore as to make it substantially impossible to get at the Another object of the present invention resides in a plastic padlock seal which facilitates handling on a high-speed production line.

A further object of the present invention resides in an all plastic seal of the type described above which can be readily manufactured at relatively low costs yet offers substantial ease of handling and safety against tampermg.

A further object of the present invention resides in an all plastic padlock seal which excells by its tamperproof characteristics yet can be readily manufactured by mass production techniques utilizing conventional injection or pressure molding.

A still further object of the present invention resides in a plastic seal of the type described above which obviates any after treatment of the molded seal.

These and further objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for

purposes of illustration only, one embodiment in accordance with the present invention, and wherein FIG. 1 is an elevational view of a plastic padlock seal according to the present invention in the open condition;

FIG. 1A is a partial elevational view showing a modification of the FIG. I arrangement;

FIG. 2 is an elevational view, similar to FIG. 1, but illustrating the seal in a closed condition, with the housing enclosing'the locking socket in cross-section;

FIG. 3 is a cross-sectional view taken along line III- III of FIG. 1;

FIG. 4 is a cross-sectional view taken along line IV- IV of FIG. 1;

FIG. 5 is a partial elevational view, on an enlarged scale, and illustrating certain details of the hinge structure in accordance with the present invention, taken in the direction of arrow 6;

FIG. 6 is a side elevational view of the seal of FIG. 5;

FIG. 7 is a partial bottom view illustrating certain details of the socket housing, and

FIG. 8 is a partial cross-sectional view, on an enlarged scale, illustrating the details of a tamper-proof socket construction in accordance with the present invention, taken along line VIII-VIII of FIG. 7.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, reference numeral 10 generally designates a tie-member or strap which is of suitable cross-section such as of substantially flat rectangular cross-section (FIG. 4) or any other suitable cross-section, i.e., in the shape ofa tube, l beam, T beam, L, etc., and which is provided at its free end with a locking head generally designated by reference numeral 20. The tie-member 10 is connected at the other end to one side of a seal body generally designated by reference numeral 30 by way of a hinge-like structure generally designated by reference numeral 50. The seal body includes at the other side thereof with a locking housing generally designated by reference numeral 40 which is provided with a locking socket for the locking head 20 as will be described more fully hereinafter.

The head 20 essentially consists of a head portion 21 (FIG. 1) of approximately conical shape, but having a generating surface that is slightly curved rather than being rectalinear. The head portion 21 is adjoined at its flat end surface 21 by a tampering section 22 having its smallest diameter adjacent to the end surface 21, thus forming a shoulder. The tapering section 22, in turn, is adjoined by a cylindrical section 23 of a dimension substantially equal to the largest diameter of the tapering section 22. A shoulder 24 forming an abutment surface is constituted by the difference in diametric dimensions between the cylindrical portion 23 and the cylindrical portion 25, the latter passing over into the flat tiemember 11 having a width W (FIG. 1) that is substantially greater than its thickness T (FIG. 4). The head portion 21, the tapering section 22, as well as the cylin-'

drical sections

23 and 25, all have a cross-section axially symmetrical to the axis X-X, i.e., forming a circu lar cross-section. However, it is understood that the present invention is not limited to a circular cross-section for these parts but may also be utilized with a substantially flat head 20, i.e., a head 20 whose cross-section is substantially rectangular, with a dimension of the rectangle that is larger than the corresponding dimension shown in FIG. 1 for the respective elements and a thickness which is slightly greater than the thickness W of the tie-member 10 (FIG. 4).

The body 30 in the illustrated embodiment is of approximately rectangular shape and of a thickness substantially equal to the thickness of the tie-member 10. However, the relatively flat body 30 may also be of any other suitable configuration and thickness, as may be desired for a particular use, for example, to contain a desired information on its front an/or back surface which may be formed thereon directly during the-molding operation. Additionally, the body 30 may be pro vided with a rim 31 surrounding the main surface 32 recessed relative thereto which will receive the information. Since this information may be realized, for instance, by suitable engraving of the mold, the base 30 can be made to appear attractive.

The hinge-like structure 50 is formed in effect by an enlarged portion 51 of substantially rectangular configuration as viewed in the direction of arrow 5 (FIG. 2), that has a dimension d (FIG. 5) greater than the thickness d' of the tie-member 10. On the other hand, the thickness of the hinge-like structure 50 is relatively slight as can be seen from FIG. 6 so as not to impair'its hinge action. A crease in the form of a slight transversely extending groove 52 enhances the hinge-effect without in any way affecting the lateral guidance pro-,

vided by the hinge-like structure against movements in a direction other than the plane of its intended pivot movements about the hinge axis y-y. As mentioned before this stability and guidance is obtained by the enlarged portion 51 which prevents in effect a twisting of the tie-member 10 relative to the seal body 30. This stability is greatly enhanced by the fact that the spacing of the lower edge 10 of the tie-member 10 from the opposite edge 30' of the base 30 (FIG. 1) is relatively small, for example,of the order of 0.100 of an inch, though this dimension may vary depending on thickness of material, type of material, and size of the seal.

To prevent withdrawal of the head after closing of abutment 24 so that the head 20 can be inserted into the bore 43 with its head portion 21, tapering section shape. The length of the frusto-conical opening 45 formed by the locking fingers is thereby substantially equal to or very slightly larger than the length of the tapering section 22 and the length of the bore 43 is thereby substantially equal to or very slightly larger than the length of the cylindrical section 23 so that the head portion 21 snaps into its locked position with the flat surface 21 thereof engaging against the end surfaces 44' of the prong-like fingers 44 when the abutment engages the end face 42 of the housing 40.

By making the ratio of the length L to the diameter D (FIG. 2) sufiiciently large, for example by making this ratio greater than 5:2, it will be impossible to get at the prongs 44 when the seal is closed, particularly if the diametric dimensions D are relatively small, for example of the order of a quarter inch or less. However, in order to further enhance the tamper-proof characteristics of the seal according to the present invention, inwardly projecting flutes 47 of approximately triangular cross-section and arranged intermediate the locking fingers 44 are provided on the inside of the housing 40, which extends essentially from the open end of the cylindrical housing 41 to the tapering part 42 thereof.

' Owing to the presence of the flute-like projections 47,

the head portion 21 is substantially prevented from being moved to any substantial extent in in the trans verse direction, i.e., in a direction at an angle to the axis of the housing 40, thus making it impossible to withdraw the head 20 out of the socket 44 by wiggling it back and forth while attempting to spread the prongs 44 apart. Furthermore, in the event of an excessive force used in the attempt to open the seal, the member would break at its intentionally weakened place in the area of the connection between the head portion 21 and tapering section 22, thereby indicating the tamperin g with the seal.

In the illustrated embodiment, three prong-like locking fingers 45 are provided though the number thereof may be varied, depending on the cross-section of the head 20. For example, in case of a flat construction of the head 20, only two spring-like members are needed which project from the narrow sides of a corresponding rectangular bore of the housing inwardly in the direction of the axis. Similarly, in case a flat head construction is used, such flute-like projections are required only at the relatively narrow sides of the rectangular cross-section of the housing projecting in a direction toward the axis of the housing to reduce the available internal space in a direction of the larger dimension of the rectangle.

Of course, other additional weakened places may be provided near the head portion, for example, in the form of a hole 60 in the end of the cylindrical section 25 adjacent the section 24 as illustrated in FIG. 1A or .at any other place of the strap 10. In the alternative,

While we have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art and we, therefore, do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed in the scope of the appended claims.

What I claim is:

1. A seal comprising: a locking socket means, a tiemember including a locking head means adapted to be lockingly retained in the socket means in both the direction of insertion and in the opposite direction upon insertion thereof into the socket means, and hinge-like connecting means having a hinge axis and operatively connecting said tie-member to said locking socket means, said connecting means including means for imparting substantial stability to the tie-member by permitting relatively unrestricted pivotal movement of the tie-member about said hinge axis in a pivot plane extending substantially perpendicular to said hinge axis while resisting movement of the tie-member out of said pivot plane and while resisting pivotal movement of the tie-member in said pivot plane about other than said hinge axis, that portion of said tie-member between the locking head means and the hinge axis being substantially rigid for assuring alignment of the locking head means with said socket means when said tie-member is pivoted about said hinge to close the seal.

2. A seal according to claim 1, characterized in that all the parts of the seal essentially consist of synthetic resinous material.

3. A seal comprising: a locking socket means, a tiemember including a locking head means adapted to be lockingly retained in the socket means in both the direction of insertion and in the opposite direction upon insertion thereof into the socket means, and hinge-like connecting means operatively connecting said tie-member to said locking socket means for imparting substantial stability to the tie-member in the plane of its pivot movements about the hinge axis, the hinge-like connecting means being formed by an enlarged portion having a substantially greater dimension in the direction of its hinge axis than the thickness of the adjacent part of the tie-member and of a seal body.

4. A seal according to claim 3, characterized in that the hinge axis is formed in effect by a fine groove in the enlarged portion.

5. A seal according to claim 4, characterized in that said tie-member is of approximately rectangular crosssection with the larger dimension of the rectangle in the direction of the plane of pivot movements being a largemultiple of the thickness thereof in a direction perpen dicular to said plane.

6. A seal according to claim 5 characterized in that said socket means includes finger-like elements and a sleeve-like housing with bore means extending therethrough, said housing being open at both ends of the bore means and fully enclosing said locking elements, said locking elements being disposed near one end of said bore means, and the ratio of the dimension of the housing means in the axial direction of the bore means to the smallest cross sectional dimension of the bore means at the other end is such as to substantially preclude access to the locking fingers from said other open end when the said head means is inserted into the socket means through the one end of said bore means.

7. A seal according to claim characterized in that said ratio is at least 5:2.

8. A seal according to claim 7 characterized in that the smallest cross sectional dimension is of the order of 0.2 inch.

9. A seal according to claim 6, characterized in that the housing is provided in said bore means with inwardly projecting means substantially minimizing the freedom of movement of the said head means within the bore means, when in the locked portion thereof, in a direction transverse to said axis.

' 10. A seal according to claim 9, characterized in that said last mentioned means are formed by substantially longitudinally extending flute-like elements provided on the inside of the housing means.

11. A seal according to claim 10, characterized in that the said head means is provided with a weakened section forming a place of intentional failure in case of tampering with the seal.

12. A seal according to claim 1 characterized in that said socket means includes finger-like locking elements and a sleeve-like housing with bore means extending therethrough, said housing being open at both ends of the bore means and fully enclosing said locking elements, said locking elements being disposed near one end of said bore means, and the ratio of the dimension of the housing means in the axial direction of the bore means to the smallest cross sectional dimension of the bore means at the other end is such as to substantially precludeaccess to the locking fingers from said other open end when the said head means is inserted into the socket means through the one end of said bore means.

13. A sea] according to claim 12 characterized in that the housing is provided in said bore means with inwardly projecting means substantially minimizing the freedom of movement of the said head means within the bore means, when in the locked portion thereof, in a direction transverse to said axis.

14. A seal according to claim 13 characterized in that said last mentioned means are formed by substantially longitudinally extending flute-like elements provided on the inside of the housing means.

15. A seal according to claim 1, characterized in that the said head means is provided with a weakened section forming a place of intentional failure in case of tampering with the seal.

16. A seal according to claim 1, characterized by further means in the member constituting a weakened place such that it breaks before the head means breaks off when subjected to straight tension.

17. A seal according to claim 16, characterized in that said further means is near the head means.

18. A seal according to claim 17, characterized in that said further means retains said tie-member sufficiently rigid to keep the head means aligned with the plane of the tie-member.

19. A seal according to claim 16, characterized in that said weakened place surrounds a bore extending through a portion of said member, said bore being spaced from said head means such that the member breaks at a location outside of the socket means.

Claims

1. A seal comprising: a locking socket means, a tie-member including a locking head means adapted to be lockingly retained in the socket means in both the direction of insertion and in the opposite direction upon insertion thereof into the socket means, and hinge-like connecting means having a hinge axis and operatively connecting said tie-member to said locking socket means, said connecting means including means for imparting substantial stability to the tie-member by permitting relatively unrestricted pivotal movement of the tie-member about said hinge axis in a pivot plane extending substantially perpendicular to said hinge axis while resisting movement of the tie-member out of said pivot plane and while resisting pivotal movement of the tie-member in said pivot plane about other than said hinge axis, that portion of said tie-member between the locking head means and the hinge axis being substantially rigid for assuring alignment of the locking head means with said socket means when said tie-member is pivoted about said hinge to close the seal.

1. A seal comprising: a locking socket means, a tie-member including a locking head means adapted to be lockingly retained in the socket means in both the direction of insertion and in the opposite direction upon insertion thereof into the socket means, and hinge-like connecting means having a hinge axis and operatively connecting said tie-member to said locking socket means, said connecting means including means for imparting substantial stability to the tie-member by permitting relatively unrestricted pivotal movement of the tie-member about said hinge axis in a pivot plane extending substantially perpendicular to said hinge axis while resisting movement of the tie-member out of said pivot plane and while resisting pivotal movement of the tiemember in said pivot plane about other than said hinge axis, that portion of said tie-member between the locking head means and the hinge axis being substantially rigid for assuring alignment of the locking head means with said socket means when said tiemember is pivoted about said hinge to close the seal.

3. A seal comprising: a locking socket means, a tie-member including a locking head means adapted to be lockingly retained in the socket means in both the direction of insertion and in the opposite direction upon insertion thereof into the socket means, and hinge-like connecting means operatively connecting said tie-member to said locking socket means for imparting substantial stability to the tie-member in the plane of its pivot movements about the hinge axis, the hinge-like connecting means being formed by an enlarged portion having a substantially greater dimension in the direction of its hinge axis than the thickness of the adjacent part of the tie-member and of a seal body.

5. A seal according to claim 4, characterized in that said tie-member is of approximately rectangular cross-section with the larger dimension of the rectangle in the direction of the plane of pivot movements being a large multiple of the thickness thereof in a direction perpendicular to said plane.

7. A seal according to claim 5 characterized in that said ratio is at least 5:2.

10. A seal according to claim 9, characterized in that said last mentioned means are formed by substantially longitudinally extending flute-like elements provided on the inside of the housing means.

12. A seal according to claim 1 characterized in that said socket means includes finger-like locking elements and a sleeve-like housing with bore means extending therethrough, said housing being open at both ends of the bore means and fully enclosing said locking elements, said locking elements being disposed near one end of said bore means, and the ratio of the dimension of the housing means in the axial direction of the bore means to the smallest cross sectional dimension of the bore means at the other end is such as to substantially preclude access to the locking fingers from said other open end when the said head means is inserted into the socket means through the one end of said bore means.

13. A seal according to claim 12 characterized in that the housing is provided in said bore means with inwardly projecting means substantially minimizing the freedom of movement of the said head means within the bore means, when in the locked portion thereof, in a direction transverse to said axis.