Plastic belt buckle with interlocking prong catches

A buckle including an auxiliary locking feature includes a female buckle part, including a strap-receiving portion and a body portion defining a recess for receiving a mating portion of a male buckle part and a pair of edge recesses. The male buckle part also has a strap-receiving portion and a pair of flexible female buckle-engaging prongs having catches which snap over mating recesses of female member. The male member also has a resilient cantilevered tongue carrying a release button extending through an opening in the front of the female part, the tongue including integral stop members. The prongs include bosses which engage the stop members. When the prongs are inserted into the recess of the female member, they snap over the mating recesses of the female member and the tongue is pressed downwardly to cause the release button to snap into the opening. With catches engaged, the stops align with the bosses on the prongs preventing the prongs from being depressed to release the buckle until the release button is depressed. Depressing this button moves the stops away from the bosses and allows the prongs to be moved inwardly into the buckle to release the catches. An improved modification of the above-described embodiment includes upwardly and downwardly directed interleavable tapered surfaces on the stops and bosses to prevent simultaneous contact of the release button during inadvertent inward movement of the prongs resulting in release of the buckle.

BACKGROUND OF THE INVENTION

In recent years, there has been a tremendous advance in the development of effective plastic buckles for use on belts and in joining straps for backpacks and other applications. The buckles are generally rectangular in shape, with a belt or strap loop attachment by at each end. One part is identified as the receptor or female part, and the other the male or engaging part, and the loop attachments are cross bars on the outer ends of each of the male or female part. The two parts interlock and typically the receiving part has an attractive front surface which may be ornamented in many respects or left plain.

In these buckles, the engaging part normally includes a pair of locking prongs at the top and bottom, and a tongue or tang in the center to guide the mating of the two parts when buckling the device. The tongue or tang is inserted into the receptor part and the prongs are flexible and have integral catches which extend upward and downward in relationship to the face of the buckle. The buckle receiver typically has openings top and bottom where the prongs may be contacted and with the first finger and thumb to be squeezed together simultaneously to release the top and bottom catch allowing the buckle to slide open. Often guide rails are contained within the receiver body and similar rails or grooves are present on the tang to ensure that the two parts engage in a smooth, straight, sliding movement. This class of buckle is the subject of the John Bianchi U.S. Pat. No. 4,991,272 assigned to the assignee of this application and U.S. Pat. No. 5,222,279, as well as U.S. Design Pat. No. D341,105.

The combination of the two prongs with catches and guiderails gives a degree of protection from the buckle becoming only partly engaged and inadvertently released.

Others have thought to add some further protection from unintended release, such as a button that must be released, in addition to the intended release of the two prong catches. Such a secondary button has appeared on the front face of the receiver and acts as a third catch. Such a latch is illustrated by U.S. Pat. No. 5,774,956. In that system, the button must be actuated simultaneously with the two edge prongs.

Simultaneous operation does not appear to be desirable and instead it would appear preferable that the actuating button should act as an overriding lock of the top and bottom prongs preventing their release through mechanical interaction between the front button and each of the top and bottom prongs.

BRIEF SUMMARY OF THE INVENTION

Faced with this state of the art, it appeared that an independent button-controlled lock might add an additional degree of security, but in actuality, it is a modest addition to the buckle. It has been very clear that one can unintentionally release one of the prong catches merely by a downward pressure on the top prong catch or by an upward pressure on the bottom prong catch. Since these are often not readily visible, it is possible for one of the catches to be released, and then the second one released, and then the total integrity of the buckle rests solely on any button and its third catch. For the most effective buckle, one does not want three independent catches, any one of which can be released independently of the others.

From the foregoing, it was determined that the most effective use of the third button is one that does not have a catch but blocks release of either top or bottom prong until it is actuated. It automatically releases both the top and bottom prongs so that neither the top nor the bottom prong catches can be disengaged without first releasing the third catch. In such a case, the thumb and index finger are used to release the top and bottom prong catches as in the past. Another finger is used to operate the button and allow the top and bottom prongs to move. This allows both the top and bottom prong catches to be released by thumb and finger pressure. Therefore, the three interconnected release devices are effective to maintain the buckle engagement at all times when engagement is intended.

Described herein are several embodiments of this invention namely:

1) a resiliently mounted front button embodiment with a button that is depressed inwardly to allow flexing movement of the top and bottom prongs for their release;

2) a sliding front catch optionally protected by side ribs and likewise must be first operated to allow inward flexing of the top and bottom prongs;

3) a rotating front latch similarly protected and similarly operative;

4) a front button embodiment where the front button is formed integrally in the female buckle part and thereby always protected within the buckle body; and

5) a resiliently mounted front button version, including a centrally positioned tongue which is depressed inwardly to allow flexing movement of the top and bottom prongs for their release, including interfitting surfaces on one of the prongs and the tongue, which is overlapped by other interfitting surfaces on the other of said prongs and tongue thereby providing a further structure to prevent unlocking the buckle without first depressing the tongue. The preferred embodiment of this version 5) includes mating interfitting surfaces on the tongue and top and bottom prongs which must not interfit for the prongs to release. Interfitting prevents unintended release when engagement of the prongs takes place. The beveled tips of the tongue must drop below the interfitting plane, in order to depress enough to allow the male to leave the female half of the buckle.

These various embodiments each have preferred applications.

DETAILED DESCRIPTION OF THE INVENTION

Referring now toFIGS. 1 through 6of the drawing, a buckle generally designated10comprises a partially hollow female member11and a male member12in assembled condition with respective belt loops13and14defined by cross bars15and16, respectively. The female and male parts11and12are shown locked with the female part having recesses21and23in the upper and lower edges, respectively. The male part12, with upper and lower flexible prongs20and22, extends through the openings defined by recesses21and23of the female member11, and in locking engagement with catches40and42.

As may be seen inFIGS. 1 and 2, the female member11has a generally rectangular recess for receiving the male member12. The male member12has a three-part extension including the two prongs20and22and a resilient cantilevered tongue26carrying a release button30and integral stop members32and34. The release button30extends through the front of the female member through an opening31. Note that the prongs20and22each include a respective bosses36and38of which engage the stops32and34integral with the release button30and the cantilevered tongue26, of the male part12.

Note inFIG. 2that the button30is preferably sloped on its upper face and is not in locking engagement with the female part and does not include any mating catch. In accordance with this invention, whenever the buckle is engaged, the male member12, including prongs20and22is inserted into the receptacle R of female member11until catches40and42snap over the mating recess edges of female member11.

At the same time, tongue26is depressed downwardly or behind the front face of member11until it reaches opening31, when button30snaps into opening31. When catches40and42are thus engaged, the stops32and34engage bosses36and38on the male member, and the prongs20and22cannot be depressed to release the buckle until the button30is depressed. The depression must be sufficient to move the button30and its stops32and34away from the integral bosses36and38. This will allow the prongs20and22to move inwardly into the buckle, namely, downward inFIG. 1for prong20and upward in the same figure for prong22thereby releasing catches40and42.

This action can easily be accomplished by grasping prongs20and22with the right-hand thumb and a finger and simultaneously applying pressure with the forefinger to depress button30. The same, of course, can be accomplished using the left hand. The button30and its stops32through34cooperate to positively lock prongs20and22against inward depression.

Please refer now specifically toFIGS. 3 and 4which show a slightly modified form of buckle. The button30is depressed and prongs20and22shown in dashed lines are squeezed to release the catches40and42. This can be accomplished only when the stops32and34have moved below the level of the bosses36and38. Deflection of the bosses32through34is possible due to the resilience of the tongue26. As soon as finger pressure is released from the button30and the prongs20and22have moved out of the way, the button30and its stops32and34again resume a locking position in contact or immediately adjacent to the bosses36and38as shown inFIG. 5.

FIG. 6is a cross sectional view taken along line6—6ofFIG. 5and shows the configuration of the male buckle member12as separated from female member11.

In the normal and restrained position of the tongue26and prongs20and22as shown inFIGS. 1 and 3, there is little likelihood of the prongs20and22of the male member12catching and being distorted and possibly broken. Therefore, the feature of this invention that provides locking of the buckle when engaged also provides an additional second function of protecting the male member from damage by the female member.

The First Alternate Embodiment

Although the use of the button30of the first embodiment is desirable and a preferred embodiment of this invention, it is recognized that another means for locking the male member's prongs from inadvertent release in this type of buckle, is possible. Such an arrangement, including a sliding lock, may also be employed. Such an embodiment is disclosed inFIGS. 7 through 17.

Now referring toFIGS. 7 through 9, the alternate form of female member51may be seen with a belt loop53defined by a cross bar55. The female member includes a generally rectangular recess R, best seen inFIG. 8, and a pair of edge openings57and59, similar to recesses21and23of the embodiment ofFIGS. 1 through 6for engaging prongs of the male part which is illustrated inFIGS. 10 and 11.

The female part51includes a pair of longitudinally extending ribs63and65, one on each side of an elongated opening O in the front face of the female part51and communicating with the internal recess R. Immediately adjacent to the sides of the opening O are a pair of detent members67and69which are used to provide an indication of transition from locked to unlocked position and to prevent unintended unlocking of the locking device of this embodiment. This feature is best understood in connection with the explanation, below ofFIG. 10.

The locking member of this embodiment, namely the lockout assembly70, is best seen inFIG. 9. This assembly70includes a top member, including a transversely extending bar75for finger operation, and also includes an elongated boss83shown in phantom inFIG. 9. The lockout top71rests over the front face of the female part51and is secured to the lockout bottom72which is a generally T-shaped member located within the recess R ofFIG. 7. The lockout parts top71and bottom72are secured together by a fastener such as screw85with the elongated boss83resting in a U-shaped groove81in the lockout bottom72. The lockout assembly is able to move longitudinally with respect to the female part51by finger pressure on the transversely extending bar75.

Key to the operation of this embodiment is the fact that the lockout bottom member72includes a pair of lobes77and79which extend laterally with respect to the direction of movement of the lockout assembly70. The lobes77and79therefore move from a prong locking position to secure the male buckle member52ofFIG. 10to the female member51in one position and to a prong unlocking position to allow the prongs of the male member52to be released. This is best understood in connection withFIGS. 10 and 11.

Also characteristic of the lockout assembly70is the fact that the leg of the T-shaped bottom member72includes an elongated generally rectangular recess72R that receives a tongue66of the male member50ofFIG. 16, similar to the tongue26of the first embodiment. The tongue66and the bottom lockout member72insure linear engagement of the male and female parts50and51during the buckling operation.

Now referring toFIGS. 10 through 17, the full buckle50,51is shown in locked condition with a belt segment B secured in the normal manner to the male part52by encircling its cross bar. Prongs58and60are visible extending out of respective recesses57and59. The lobes77and79of the lockout assembly70, best seen inFIG. 10, engage bosses54and56, respectively of the prongs58and60. In this condition, the prongs58and60may not be depressed since each bear against opposite sides of a rigid member, namely, the lobes77and79of the T-shaped lower lockout member72. This section of the lower lockout member72is rigid and reinforced by the tongue66as may be seen inFIG. 11in phantom, and inFIG. 16, which shows the male part50in its relationship to the lockout assembly70.

Suffice it to say, particularly by reference toFIGS. 10 and 16, the lockout assembly70is operative to allow the prongs58and60to be depressed when in the most forward position as is shown inFIG. 16and effectively prevents the compression of the prongs58and60and release of their integral catch when the lockout assembly is in the retracted position as shown inFIG. 10. The presence of the ribs63and65ofFIG. 7protect the lockout assembly70from most contact which might cause its movement from locked to unlocked position.

The ribs63and65also act to direct the user's finger in the line of locking or unlocking movements. This aids the user since only tactile reference is needed to operate the lockout assembly70. The detents67and69ofFIG. 7provide a tactile indication of movement to an unlocked or locked position. When moved to an unlocked position, the release of the buckle50still requires simultaneous or near simultaneous compression of the prongs58and60. A simple forward sliding motion of the hand allows release of the lockout assembly70by the forefinger and compression of the prongs58and60by the thumb and a finger for quick release of the buckle in one natural motion.

Second Alternate Embodiment

In further refinement of this invention, I determined that another positive locking arrangement can be achieved by using a rotary locking assembly that also serves to prevent the depression of the prongs of an edge squeeze to release type of buckle. Such an embodiment is illustrated inFIGS. 18 through 27.

Now referring toFIGS. 18 through 23which show the female member101inFIG. 18, the latched buckle, generally designated100, inFIG. 21, and the male member102inFIGS. 22 and 23. The female member101includes a belt loop defined by a cross bar103, a pair of edge recesses105and107, and a generally rectangular recess101R. Female member101likewise includes a pair of ribs109and111and a circular opening113ofFIGS. 18 and 22. The opening113receives a rotary lockout assembly, generally designated115ofFIG. 20.

The rotary lockout assembly115includes a top lockout member116with an integral crossbar117that is used to rotate the lockout assembly115from a locked to an unlocked position by the user. The top lockout member116includes a disc portion119resting on top of the front face of the female member101between the ribs109and111. A spline121extends from the lower face of the disc portion119through the circular opening113in female port101and engages a lower or bottom rotary lockout member123carrying a pair of lobes125and127. These lobes125and127are dimensioned so that they will bear against the prongs104and106of the male member102when in a locked orientation. When the rotary lockout member115is rotated away from the locked orientation, allows the prongs104and105of the male member102to be pressed inwardly and unlatch.

FIG. 21shows the latched and locked buckle100. A 90-degree rotation in either direction places the buckle100in an unlocked condition ready for unlatching by pressure on the prongs104and106of the male member102. It is also clear that less than 90-degree rotation will allow the buckle to be released by pinching the prongs104and106simultaneously and drawing the male and female parts102and101apart.

The rotary lockout assembly115can be located on either the male part102or on the female part101. If located on the male part102as shown inFIG. 23, the opening113of the female part is a slot rather than a round opening. If located on the female part101, the round opening is used and the male part ofFIG. 23only includes its tongue108and lacks the rotary lockout assembly123. In either case, the rotary lockout assembly123prevents the release of the buckle by blocking the inward depression of the prongs104and106in one orientation and allows their release when the rotary lockout assembly is at any orientation other than with the lobes125and127engaging or interfering with the depression of prongs104and106.

This embodiment provides protection from any force on the front of the buckle100causing the release of the rotary lockout assembly. An intended rotary movement, usually requiring a thumb and a finger to rotate the assembly123, is necessary.

Third Alternate Embodiment

During the development of this invention, it appeared that it is also possible to make a locking buckle employing a button release on the female member, utilizing a cantilevered tongue carrying the release button to engage and release the prongs rather than through the presence of lobes. The release button can be molded integrally with the female part. This embodiment is illustrated inFIGS. 28 through 36. Fundamental to this embodiment is the fact that the cantilevered carrier of the button engages the prongs of the male part whenever the button is not depressed.

Refer now toFIGS. 28 through 36, with particular reference toFIG. 28showing the female part151,FIG. 31showing the latched and locked buckle150,FIG. 33showing the process of releasing a prong, andFIG. 34showing the male member152.

The female member151presents the same general appearance as the previously disclosed female members except that the release button153remains a part of the female member151at all times and, in fact is integrally molded into the female part. The male part152ofFIG. 34includes a pair of prongs154and156and a central forked tongue158. The tongue158aligns the male and female buckle parts152and151. The forked extensions160and162of the male part152embrace the release button153within the female part151whenever the buckle150is engaged.

The release button153is located on cantilevered release button carrier155of the female part151. The female part151, as seen in end viewFIGS. 30 and 33, includes side walls157and159which engage the prongs154and156, respectively, in a similar manner as the bosses32and34of the male member11ofFIGS. 1–7. In this embodiment, the release button carrier155and the release button153remain protected within the female member151whether the buckle150is latched or unlatched.

For an understanding of the operation of this third alternate embodiment, reference is now made toFIG. 33which shows a prong154in its buckle-releasing position as the release button153and its carrier155have moved downward under finger pressure in the direction of the arrow so that the boss154B has cleared the side wall159of the cantilevered carrier155. As the buckle separates, the prongs154and156are removed, and the finger or thumb pressure on the button is released, the plastic memory of the cantilevered carrier155returns it to its normal position within the female part151. To facilitate re-engagement, the walls157and159may be tapered to allow the prongs154and156to resume their normal locking position shown inFIG. 33by the dashed line.

Fourth Alternate Embodiment

During a later stage of the development of this invention, it appeared that the first embodiment described above could be further improved by providing an even more positive means of preventing unlocking of the buckle without depressing the center cantilevered tongue first. As discussed above, it is possible for an inadvertent downward pressure to be exerted against the top prong and an upward pressure on the lower prong. An unexpected contact with the button at that time could then release the buckle. This improved embodiment is described in connection withFIGS. 37 and 38.

FIG. 37is a composite front view of a two-part buckle in which the portions above and below the center line show certain parts in alternate positions, as described below.

FIG. 37shows the front face of a buckle generally designated180that includes a partially hollow female member182and a male member184in assembled condition with respective belt loops186and188defined by cross bars190and192, respectively. The male and female parts182and184, respectively, are shown locked together with the female part having a front face185and recesses194and196in the upper and lower edges, respectively, and the male member184with upper and lower flexible prongs198and200which extend through openings defined by recesses194and196of the female member182and in locking engagement with catches202and204. Female member182is, or may be, identical to female member11ofFIGS. 1 and 2.

The male member184has a three-part extension including the two prongs198and200, and a cantilevered resilient tongue206carrying a release button208and integral stop members210and212. Prongs198and200include bosses214and216, respectively, which engage the stop members210and212.

Each half of buckle180is symmetrical above and below center line CL. That portion ofFIG. 37below center line CL shows prong200in the position which both prongs198and200occupy when the two parts of buckle180are latched together and there is no effort to separate them. Stop member212and boss216are slightly separated but are aligned with respect to the plane of the paper. With no effort to separate buckle parts182and184, boss214and stop210would be separated as boss216and stop212are shown.

Above the center line CL, prong198is shown forced inwardly by means of a force F whose direction is indicated by the arrow. This force would normally be imposed by a wearer's thumb if the top of the drawing is viewed as up. At the same time, prong200would also be subjected to an inwardly directed force from the middle finger of the wearer. Unless button208is depressed, the interfitting of tapered or beveled edges214aand214bof boss214will become interleaved with tapered or beveled edges210aand210bof stop210and in actual contact as shown by tapered edge210aoverlying tapered edge214bas indicated by the arrow labeled C.

At the same time tapered edges216aand216bof boss216similarly become interleaved and in locking engagement with tapered edges212aand212bof stop212. With these parts interleaved, as described, button208cannot be depressed and the buckle parts182and184will not separate.

Details of this interaction between button208and prongs198and200may become easier to follow by consideration of perspective drawingFIG. 38. In this drawing, only prong198and button208are shown, prong200operating identically to prong198.

Stop member210and boss214are each formed with upward and downward sloping tapered edges210aand210band upward and downward sloping tapered edges214aand214b, respectively. Cantilevered tongue206also includes a stop212that includes a downward sloping tapered edge212aand an upward sloping tapered edge212b. Boss216of prong200(FIG. 37) also includes an upward sloping tapered edge216band a downwardly sloping tapered edge216a. It will be recognized that “upwardly” and “downwardly” are in relation to the parts shown inFIG. 38.

As the male member184, including prongs198and200and tongue206, is inserted into female member182, prongs198and200are progressively bent inwardly. At the same time, tongue206is depressed downwardly or behind the front face of female member182until it reaches an opening220(FIG. 37) when button208snaps into opening220.

A slight further movement of male member184causes catches202and204to snap over the mating recess edges194and196of female member182releasing the inward pressure on prongs198and200and permitting them to move outwardly carrying the tapered edges of bosses214and216away from stops210and212. These bosses remain aligned with stops210and212and only a very small distance away so that any inward pressure on either of prongs198or200will cause tapered edges of bosses214and216to contact tapered edges of stops210and212, preventing further inward movement of the prongs and release of the buckle.

To release the buckle, button208must be pushed downwardly, so that stops210and212and their respective tapered edges are out of alignment below bosses214and216. Then, inward pressure will move prongs198and200sufficiently far so that catches202and204will clear their mating recesses on female member182permitting male member184to be withdrawn from female member182.

It will be appreciated that it would not always be necessary to include all of the above edge surfaces to enjoy the benefits of the above described fourth alternate embodiment.FIG. 39shows a modification of the structure ofFIG. 38wherein stop210′ comprises a V-shaped edge on the side of the button208′. Boss214′ is an extension of prong198′ having an internal V-shaped groove which is complementary or mating with respect to the V-shaped edge on stop210′. Inward pressure on prong198′ will cause boss214′ to enter and latch with stop210, preventing button210from moving out of alignment with the prongs and release of the male and female buckle parts.

Boss216and stop212could be similarly modified and either one or both pairs of boss and stops may be used. Also, the V-shaped edges could be formed on prongs198and200and the V-shaped groove on button208and210.

Fifth Alternate Embodiment

Experience with the fourth alternate embodiment described above disclosed that in some configurations it was possible, particularly with a very vigorous squeeze on the prongs, for the tapered edges of the prongs and the stops to wedge or bind together, preventing the tongue206and button208from being moved out of the way of the prongs. Applicant has essentially eliminated this problem by incorporating a limit surface or small abutment on the surface of each of bosses214aand216a(FIG. 3) which limits the inward travel of prongs198and200, thereby preventing the wedging action referred to above.

This structure is shown onFIG. 40, which is very similar toFIG. 38, and in which corresponding parts have been given the same numerals. As in the case ofFIG. 38, the prong200, with boss216, does not appear in this perspective view since it is a mirror image of prong198and boss214. It will be observed that boss214, which carries tapered edges214aand216aincludes a limit surface or abutment214cpositioned to limit the extent of overlap of tapered edge210bwith tapered edge214a. Boss216preferably includes a similar abutment which limits the travel of tapered edge212b. It will be recognized that the limit surface or abutment described could also be placed on any of bosses214or216or on stop210or212so long as it is positioned to avoid the wedging action described above.

The fourth and fifth alternate constructions are also applicable to the third alternate embodiment described above.

SUMMARY

In each of these embodiments, the buckle parts are preferably fabricated by molding out of such a material as nylon or Delrin of the Dupont Engineering Polymers of Wilmington, Del. In each case, the buckle employs two catches on opposite edges of the buckle which are releasable by inwardly applied manual pressure. The embodiments also include an auxiliary stop or lobe which engages each of these catches to prevent them from releasing unless the auxiliary stop or lobe is moved aside to allow the catches to move in a releasing direction. The auxiliary stop or lobes are controlled by a resiliently mounted release button, as in the first described embodiment, the third and fourth alternative embodiments or by a sliding or rotating locking device, as in the first and second alternative embodiments, respectively. Each of these variants upon this invention are effective to add a greater degree of security to buckles for a variety of uses.

The foregoing embodiments are merely representative of the principles of this invention and are not to be considered as limiting. It is apparent that one, given the teaching present could produce buckles which incorporate the principles of this invention while still having some difference. Therefore, the scope of this invention is not to be considered limited to the embodiments shown but, instead, are defined by the following claims including the scope afforded by the Doctrine of Equivalents.