AN ENGAGEMENT LOCK, PREFERABLY FOR A CONTAINER

Abstract: In an engagement lock comprising two members (1 and 2) the first member (1) consists of a rod-shaped body of the diameter (dy) whose one end (6) is designed to be inserted into a cavity (3) of the diameter (Di) in the second member (2). The cavity (3) has an annular depression (9) containing a spring ring (10) of the thickness (t) which lockingly engages an annular depression (7) of the diameter (di) in the rod-shaped body (1) upon introduction of the rod-shaped body into the cavity (3). To ensure that the engagement lock cannot be opened without exterior indications of damage, the annular depression (9) in the cavity (3) is formed as two partial depressions (11, 12) as seen in cross-section, having the diameters (Dy) and (D), respectively, where Di<di + 2t<D<dy + 2t<Dy.

Description: Λ An engagement lock, preferably for a container The invention relates to an engagement lock, preferably for a container with locking eyes, comprising two mem¬ bers, the first one of which is formed by a rod-shaped body of the diameter d whose one end, the introduction 3 y end, is designed to be passed through the locking eyes and be inserted into a cavity of the diameter D. in the second member, and whose other end as well as said second member having such transverse dimensions that they cannot pass through the locking eyes, said cavity in the second member having an annular depression which con¬ tains a C-shaped spring ring of the thickness t hich is designed to automatically lockingly engage an annular depression of the diameter d. at the bottom of the rod- 1 shaped body upon introduction of the rod-shaped body into the cavity. Such an engagement lock is known e.g. from the Danish Patent Specification 144 619 and the British Patent Spe¬ cification 2 027 788. Engagement locks of this type are used as a combination of a lock and a seal. Opening of such locks requires a very strong tool, such as a bolt cutter, which simul¬ taneously clearly shows that the lock, which may e.g. be embossed with a number corresponding to a specific container, has been broken open. However, it has been found that all the known locks of the above-mentioned type can be opened by unauthorized persons without any exterior indications of damage to the lock, which can be relocked after the container has been broken into. Such opening is effected by urging the two members of the lock apart with a certain force while rotating them with respect to each other. During this procedure the ends of the spring ring bite into the rod-shaped member by friction so that the spring ring opens so much that it is forced into the depres¬ sion of greatest diameter in the cavity of the second member, enabling the rod-shaped body to be pulled out of the cavity. This drawback can be remedied to some extent by provid- ing the spring ring with a lubricant, e.g. grease, but still it .is not quite certain that the seal function of the lock is reliable. The object o f the invention is to overcome the mentioned very troublesome drawback of the known engagement locks. This object is achieved according to the invention in that, as seen in cross-section, the annular depression in the cavity is formed as two partial depressions, ad¬ joining in the axial direction 3 the innermost one of said partial depressions having the diameter D at the bottom, the transitional region between the partial de¬ pressions having the diameter D, where D i< + 2t <D <d + 2t<D y When an attempt is made at urging the two locking mem¬ bers apart, the spring rod is drawn up into the outer- most one of the two partial depressions in the cavity. The diameter of the outermost partial depression is too small to enable the rod-shaped body to be pulled up when the spring ring is disposed in the outermost partial de¬ pression. Of course, the members cannot be lockingly engaged either while the spring ring is in the outermost partial depression. When the two members are interlocked the spring ring is forced down into the innermost par¬ tial depression in the second member. When. he inequali¬ ties stated in the claim are satisfied, it is not pos¬ sible to open the engagement lock by urging the members apart while rotating them. When the stated inequalities are satisfied, the cross- section of the partial depressions may assume many dif¬ ferent shapes, and claims 2 to 5 define a plurality of expedient embodiments. The invention will be described more fully below with reference to the drawing, in which fig. 1 shows a known engagement lock of the present type fig. 2 shows an enlarged section of the locking mecha¬ nism and the geometry of an engagement lock according to the invention with dimension symbols, fig. 3 shows an embodiment according to the invention of a continuous cross-section of the annular depression in the second member, fig. 4 shows another embodiment according to the in- vention of a continuous ' cross-section, figs. .5-9 show five different embodiments of disconti¬ nuous cross-sections in connection with straight lines forming various angles c, with the axial direction of the cavity, and figs. 10-14 show embodiments where the cross-section ac¬ cording to the invention consists of two continuous curves meeting in a discontinuity in the transitional region where the curve forming the outermost partial de- pression has a tangent forming various angles o with the axial direction of the cavity. The engagement lock shown in fig. 1 consists of two mem¬ bers 1 and 2 designed to be automatically lockingly engaged when the first member 1, which is in the form of a rod-shaped body, is inserted into a cavit 3 in the second member 2. The engagement lock is used for locking a container, the rod-shaped body 1 being passed through locking eyes, indicated at 4 and 5 in fig. 1, of th-e container prior to its locking engagement with the second member 2 of the lock. The rod-shaped body, which has preferably a circular cross-section of the diameter d γ , has at one end, the introduction end 6, an annular dep " ression 7 of the diameter di. at the bottom and -has at the other end a head 8 of considerably greater diameter than the rod-shaped body 1 itself, so that this head 8 cannot be passed through the locking eyes 4 and 5. The second member 2 has in the cavity 3 an annular de¬ pression 9 containing a C-shaped spring or locking ring 10 of the thickness t, which is designed to lockingly engage the depression 7 upon introduction of the rod- shaped body 1 into the cavity 3. To facilitate the in¬ troduction the introduction end 6 of the rod-shaped body 1 is conically tapered. appears from the following figures 2 to 6 that the depression 9 of the invention, as shown in fig. 1, is formed as two partial depressions 11 and 12 adjoining in the axial direction, of which the innermost partial depression 11 has the diameter D at the bottom, and the transitional region 13 between the partial depressions 11 and 12 has the diameter D. - ττ ■ ^ The transitional region 13 is geometrically determined by the following inequality: 2t<0<d 2t where 2t>D ∑ and d + 2t<D v so that the condi- y Y tion may be expressed as D. <. d. + 2t<D<£d + 2t<D λ 1 • 1 As appears from figs. 3, 4, 5 and 6, the cross-section of the depressions 11, 12 may assume many different shapes when the above-mentioned condition is satisfied. As shown in figs. 3 and 4, the cross-section of the an¬ nular depression 11, 12 may be a discontinuous curve which has, in the transitional region 13, an inflexion forming an angle _ "4 15° with the axial direction 14 of the cavity or a tangent parallel with the axial di¬ rection 14. Figs. 5-9 show a plurality of embodiments in which the cross-section of the depression is a discontinuous curve with a discontinuity in the transitional region 13, from which the cross-section in a direction toward the outermost partial depression 12 forms a straight line 15 forming an angle *. with the axis 14 of the ca¬ vity. It applies to the five shown embodiments that -105° ^ < . < -90°, <= -90°, -90° < ~ <. < 0°, respectively. Finally, the cross-section of the partial depressions 11 and 12 may form a split curve with a discontinuity in the transitional region 13, from which the cross- section in a direction toward the outermost depression 12 is constituted by a curve having, in the disconti¬ nuity region 13, a tangent forming an angle c< with the axis of the cavity. It applies to the three shown em¬ bodiments that <A = -90°, -90° <c< 15° and C = 15°. -lo5° < < -90°, σ ~ = -90°, -90° < 0°, oi = 0° " and 0° < c . _ 15°, respectively.

Claims: P a t e n t c 1 a i m s 1. An engagement lock, preferably for a container with locking eyes, comprising two members, the first one of which is formed by a rod-shaped body of the dia- meter d whose one end, the introduction end, is de¬ signed to be passed through the locking eyes and be inserted into a cavity of the diameter D. in the second member, and whose other end as well as said second member have such transverse dimensions that they cannot pass through the locking eyes, said cavity in the second member having an annular depression which con¬ tains a C-shaped spring ring of the thickness t which is designed to automatically lockingly engage an an¬ nular depression of the diameter d1. at the bottom of the rod-shaped body upon introduction of the rod-shaped body into the cavity, c h a r a c t e r i z e d in that, as seen in cross-section, the annular depression in the cavity is formed as two partial depressions adjoining in the axial direction, the innermost one of said partial depressions having the diameter D γ at the bottom, the transitional region between the partial de¬ pressions having the diameter D, where 2. An engagement lock according to claim 1, c h a r a c t e r i z e d in that the annular depres¬ sion in the cavity forms a curve which is continuous as seen in cross-section and has, in the transitional re¬ gion, an inflexion forming an angle _ 15° with the axial direction of the cavity (fig. 3). I 3. An engagement lock according to claim 1, c h a r a c t e r i z e d In that the annular depres¬ sion in the cavity forms a curve which is continuous as seen in cross-section and has, in the transitional region, a tangent parallel with the axial direction of the cavity (fig. &}- 4. An engagement lock according to claim 1, c h a r a c t e r i z e d in that the annular depres¬ sion In the cavity forms a curve which is discontinuous as seen In cross-section and has a discontinuity in the transitional region, from which the cross-section in a direction toward the outermost partial depression is formed by a substantially straight line forming an angle c.wlth the axis of the cavity, where -105° ^ <^ _ + 15° (fig. 5). -. An engagement lock according to claim 1, c h a r a c t e r i z e d in that the annular depres¬ sion in the cavity forms a curve which Is split as seen in cross-section and has a discontinuity In the transi¬ tional region from which the cross -section in a direc¬ tion toward the outermost partial depression Is formed by a curvilinear curve having in the discontinuity region a tangent forming an angle the axis of the cavity, where:

Inventors: SOERENSEN FLEMMING, SOERENSEN, FLEMMING
Applicants: ONESEAL APS
Application year: 1984
Main classification: G09F3
IPC codes: E05B39, G09F3