EP0566856A1

EP0566856A1 - End release buckle with pivoting pawl release

Info

Publication number: EP0566856A1
Application number: EP93103921A
Authority: EP
Inventors: James R. Anthony; David D. Merrick; Douglas W. Bittner
Original assignee: Indiana Mills and Manufacturing Inc
Current assignee: Indiana Mills and Manufacturing Inc
Priority date: 1992-04-23
Filing date: 1993-03-11
Publication date: 1993-10-27
Also published as: MX9302209A; CA2091526A1

Abstract

An end release buckle (10) with a pivoting pawl release (13). There is provided a buckle (10) for a safety belt harness in which the buckle (10) includes one or more levers (60) to assist in lifting a pawl (12). A push button (15) is used to move the lever arms (60), which lift the pawl (12). Ramps (83) may be included in the buckle (10), and are positioned so as to slide under and lift the pawl (12) as it is being lifted by the levers (60). The pawl levers (60) are positioned so that the lever feet (61) underlie and may lift the pawl (12). In addition, the levers (60) may include pawl blocks (62) to overlie the pawl (12) and prevent it from being disengaged without the levers (60) being moved, and may further include indents (65) in the pawl blocks (62) to prevent the pawl (12) from slipping away from the block (62). A dual button embodiment in which the pawl levers may be pivoted by depressing either of two buttons is also disclosed.

Description

FIELD OF THE INVENTION

This invention relates generally to tongue and buckle fasteners such as are typically employed in safety belt harnesses, and more specifically to a tongue and buckle fastener having an improved mechanism for releasing the tongue from the buckle.

BACKGROUND OF THE INVENTION

Safety belt harnesses of the prior art employ a variety of means to secure and release the belt. Most commonly, a tongue and buckle combination is employed so that the harness can be quickly and easily fastened or released. With these buckles, it is known to use a tongue having one or more apertures so that when the tongue is inserted into the buckle it may engage a pawl. The pawl typically drops into the tongue aperture when the tongue is fully inserted into the buckle, holding the tongue securely in place. When the pawl is disengaged from the tongue aperture, the tongue can be removed from the buckle and the safety harness released.
A variety of means to cause the pawl to be released from the tongue are known to the art. In some models, the top plate of the buckle is connected to the pawl and acts to pull the pawl from the tongue aperture when the buckle plate is lifted. These buckles are simple in operation and construction, but typically require that the buckle plate be lifted before the tongue can be inserted and engaged. In other models, a push- button mechanism is used to push the pawl from the tongue aperture. These models are generally more complicated in both design and construction, but they typically offer the advantage of allowing the tongue to be inserted into and engaged by the buckle without depressing the button. This design is significantly easier to use when inserting the tongue into the buckle, and is therefore preferred for many safety belt applications.
In push-button buckles, it is known to locate the button on the top of the buckle housing where it may be pressed downward to disengage the pawl. Alternatively, the button may be located at the end of the buckle where it may be pressed inward to perform that same function. In both models, springs may be used to bias the pawl to its engaged position and/or to eject the tongue when the pawl is disengaged. The spring-loaded tongue ejector may also function to prevent the pawl from dropping into its lowered position when the tongue is removed, thereby allowing the tongue to be inserted into the buckle without re-lifting the pawl.
In push-button buckles having the button at the front end of the buckle, it is common to use one or more ramps connected to the button to lift the pawl above the upper surface of the tongue. As the button is pushed into the housing, the ramps slide under the pawl, lifting it upward. When the button is fully depressed, the pawl is raised above the upper surface of the tongue, allowing the tongue to be inserted or withdrawn.
In end release buckles using ramps to disengage the pawl, the friction between the ramp and the pawl resists the sliding motion and causes considerable wear on the pawl and ramp surfaces. The wear causes the ramped surfaces to become rough and bumpy, creating even greater resistance to the sliding motion. In addition, the increased wear may cause the buckle mechanism to develop rough spots or hitches which may further inhibit the smooth operation of the buckle. Both of these conditions make the buckle more difficult to operate, and in certain circumstances may even prevent the safety harness front being quickly disengaged when needed.
A need therefore exists for an improved end release buckle which resists ramp wear and requires minimal force to lift the pawl from its aperture. Toward that end, it is desired to provide a buckle which does not rely exclusively on ramps to lift the pawl, and instead utilizes a more mechanically efficient means to perform that function. The present invention addresses that need.

SUMMARY OF THE INVENTION

An improved tongue and buckle combination, according to one embodiment of the present invention, includes a tongue with an aperture to receive a pawl, and a buckle having a pawl to engage the tongue. The buckle also includes a lever to disengage the pawl from the tongue, and a device to pivot the pawl lever on the fulcrum. In the preferred embodiment, the device to pivot the pawl lever on its fulcrum is attached to a push-button which is slidably received on the buckle frame. The push-button may also include side ramps to assist in lifting the pawl. In addition, the pawl lever may include one or more pawl blocks, which may further include indents to prevent the pawl from slipping away from the block when the block is engaged Finally, a dual button buckle having pawl lifting levers is disclosed.
One object of the present invention is to provide a tongue and buckle combination which requires less force to operate, and can therefore be operated by those with injuries or other physical infirmities.
Another object of the present invention is to provide a button-type buckle having increased resistance to wear, and providing a smoother, more consistent operation over the life of the buckle.
Related objects and advantages of the present invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view in full section of the end release buckle of the present invention, according to one preferred embodiment.
FIG. 2 is a front elevational view of the frame and pawl of the end release buckle of the present invention, according to one preferred embodiment.
FIG. 3 is a side elevational view of the frame and pawl of the end release buckle of the present invention, according to one preferred embodiment.
FIG. 4 is a top plan view of tire first frame member of the end release buckle of the present invention, according to one preferred embodiment, showing the apertures contained therein.
FIG. 5 is a perspective view of the pawl of the end release buckle of the present invention, according to one preferred embodiment.
FIG. 6 is a perspective view of the pawl lever assembly of the end release buckle of the present invention, according to one preferred embodiment.
FIG. 7 is a side elevational view of the pawl lever assembly of the end release buckle of the present invention, according to one preferred embodiment.
FIG. 8 is a side elevational view in full section of the push-button of the end release buckle of the present invention, looking along line 8--8 of FIG. 9 in the direction of the arrows.
FIG. 9 is an end elevational view of the push-button portion of the end release buckle of the present invention.
FIG. 10 is a side elevational view in full section of the end release buckle of the present invention, after the button has traveled in the direction of arrow "A".
FIG. 11 is a side elevational view in full section of the push-button assembly of the end release buckle of the present invention, according to one preferred "double button" embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, FIG. 1 shows the basic components of the present invention. Buckle 10 includes a frame 11, a pawl 12, a pawl lever 13, and means 14 to pivot the pawl lever on its fulcrum. In the preferred embodiments, means 14 for pivoting the pawl lever on its fulcrum is attached to a push-button 15 which is slidably received on the frame. Pawl lever 13 preferably includes shoulders 16 which rest on ears 17 in the frame, the lower portion of the frame ears acting as a fulcrum on which the lever 13 may pivot.
The entire buckle mechanism is substantially enclosed by a housing 18. The front end of the housing is open to allow a tongue attached to one belt of a safety harness to be inserted into the buckle assembly. The rearward end of the housing is preferably open to allow the frame to extend therethrough. As will be further illustrated in later figures, this end of the frame preferably includes an aperture to allow the other belt of a safety harness to be attached thereto.
The tongue 19 of a safety Harness buckle may be inserted into or removed from the buckle by movement in the direction of the arrows shown in FIG. 1. The tongue of the present invention has an aperture near the end which is inserted into the buckle, said aperture being sized to receive a pawl. The other end of the tongue is of course attached to one belt of the safety harness.
FIGS. 2, 3 and 4 show frame 11 in greater detail, and further illustrate pawl 12 in its raised position. As is shown in FIG. 2, frame 11 includes a first frame member 20, and a second frame member 21. First frame member 20 is generally planar in shape, while second frame member 21 includes both planar and channel-shaped portions. The planar portions of the two frame members are preferably joined together, so that frame 11 comprises one integral frame.
The channel-shaped end of second frame member 21 includes a lower wall 22, and two side walls 23a and 23b. First frame member 20 and lower wall 22 are positioned in a spaced-apart relation, so that a passageway 25 is defined by the space therebetween. Passageway 25 is sized to receive tongue 19 of the tongue and buckle combination.
As is shown in FIGS. 2 and 3, side walls 23a and 23b extend upward past first frame member 20 along several portions of the channel section. Frame ears 17 are formed in these side walls near the forward end of the channel, and are sized to receive the shoulders of pawl lever 13. The rearward end of a leaf spring 28 is mounted on the frame by securing it to a cover piece 26 attached to the rearward portion 29 of the frame. The opposite, forward end of leaf spring 28 serves to bias the pawl to its downward position.
Various apertures are included in the frame members, as is shown in FIG. 4. In particular, a belt aperture 30 is included near one end of the frame, so that a safety belt may be attached thereto. A pawl aperture 31 is included near the other end of the frame, to receive the pawl. Side apertures 32 and 33 are included in first frame member 20, so that side walls 23a and 23b may protrude therethrough.
The pawl 12 of the present invention is shown in FIG. 5, and includes a pawl tab 50, side legs 51, upper indent 52, side indents 53 and pawl shoulders 55. Pawl tab 50 is sized to engage the aperture of the tongue, and is also adapted to pass easily through frame aperture 31. Side legs 51 are positioned to pass through frame apertures 32, and provide lateral stability for the pawl. Indent 52 accepts leaf spring 28 which provides a downward bias to the pawl.
As is shown in FIGS. 6 and 7, pawl lever 13 preferably includes lever arms 60, lever feet 61, pawl blocks 62, and lever shoulders 63. In the preferred embodiment, each pawl lever assembly includes two of each component, so that a dual lever construction is provided. Lever arms 60 preferably include an upper end portion 68 which is somewhat wider than the remainder of the arm to assure that the lever arm is engaged by pivoting means 14. Further, it is preferred that the lever arms be bent slightly forward near their upper end portions 68, so that the ends of the lever arms contact pivoting means 14 when said means engages the arm. When the end of the lever arm contacts and is moved by the pivoting means, the effective length of the lever arm is at a maximum, and the force required to pivot the lever arm is reduced.
Although the preferred lever arms are bent slightly forward, it is to be appreciated that the upper end portions 68 of levers 60 may alternatively be coplanar with the levers to engage the rearward facing contact surface of means 103, thereby causing the pawl to pivot as means 103 is moved rearwardly. Similarly, the lever arms may include such bends and curves as are required to enable the levers to fit comfortably inside the buckle assembly.
Lever shoulders 63 are received in frame ears 17, and extend somewhat through, and rest on, said ears. Thus, the lower surfaces of frame ears 17 provide a fulcrum on which the lever assembly may pivot. Pawl blocks 62 may include indents 65 to engage the pawl in the event that the pawl is inadvertently released.
Lever feet 61 are formed to underlie and lift the pawl from the aperture when lever arms 60 are pivoted on their fulcrum. The lever feet are positioned within and engage side indents 53 of the pawl, so that the lever feet lift the pawl when the lever arms are pivoted downward. Note that the lever feet are not fixedly attached to the pawl, but rest securely between the pawl and the upper frame member 20 when the pawl is in its lowered position.
FIGS. 8 and 9 show a single-button assembly according to one preferred end release button embodiment. Button assembly 80 includes means 81 to pivot the lever arms downward, button 82, button ramps 83, and channels 84 to slidably secure the button assembly to the frame. Channels 84 engage the laterally extending edges 41 of frame member 20, so that the button assembly may slide freely along the forward portion of the frame. Button assembly 80 may further include upper wall 90 and side walls 91 to connect and secure the various button components in their respective positions. For example, means 81 to pivot the lever arms downward are preferably attached to upper button wall 90. Similarly, a helical spring may be secured to the button assembly by attaching it to knob 89 on the upper wall.
In operation, the buckle of the present invention provides dual means for lifting a pawl to receive and/or release an apertured tongue. When end button 82 is pushed in the direction of arrow A in FIG. 10, means 14 engages pawl levers 13, pivoting the ends of said levers downward. Lever feet 61, which protrude under the pawl, lift the pawl upward as the lever pivots on its fulcrum. In addition, button ramps 83 slide under pawl shoulders 55 as the button is pushed inward, and assist in raising the pawl. In the preferred embodiment, the ramps are positioned so that the levers engage the pawl first, so that the levers begin lifting the pawl upward shortly before the ramps begin to work.
In an alternative embodiment, the button assembly may include two buttons--one preferably an end button substantially as described above, and the other a top button which may cooperate with the end button. As is shown in FIG. 11, dual button assembly 100 includes an end button 101, a top button 102, and means 103 to pivot the lever arms downward. As was shown in the single button embodiment, channels 105 are included so that the button assembly can be slidably retained on the frame. As was also illustrated in the foregoing description, button ramps 109 may be included, and are preferably positioned to lift the pawl upward in cooperation with the levers.
Means to allow the top button to be pivoted downward are also preferably included. In the preferred embodiment, said means comprises a hook 108, extending downwardly from upper wall 107 of end button 101, to retain an outwardly extending arm 106 attached to top button 102. Arm 106 is pivotably received in hook 108, so that top button 102 may pivot downwardly to cause means 103 to engage the lever arms.
It is preferred that top button 102 and means 103 to pivot the lever arms downward are joined as one piece. Accordingly, when top button 102 is depressed, means 103 acts to pivot the levers on their fulcrum. Alternatively, when end button 101 is pushed, means 103 is also moved. The buckle housing may further include a ramped portion 110 directly behind and adjacent to the top button 102, to depress the top button when end button 101 is pushed into the housing. Ramped portion 110 extends downwardly and rearwardly from the button housing, and serves to cause means 103 to move both downward and back when end button 101 is pushed. In addition, the side walls of the housing may include ramps to guide the push-button downwardly as the button is depressed.
Push button 102 may be returned to its upward position by the force exerted by lever arms 13 on means 103 as the pawl is forced downward by leaf spring 28; however, the top button assembly preferably includes an additional wire spring 112 to bias the top button to its upward position. Preferred spring 112 is a wound wire spring mounted to and extending from end button 101, to normally urge top button 102 to its upward position.
The operation of the double button embodiment is substantially the same as the operation of the single button model. When either button is engaged, means 103 causes the lever arms to pivot on their fulcrum, lifting lever feet 61 and raising the pawl. It is still preferred to position the ramps so that they do not engage the pawl until the levers have initiated the lifting action.
It is to be appreciated that with the double button embodiment the user can cause the pawl to be raised by operating either button. Regardless of which button is depressed, means 103 moves back and down, causing the lever arms to lift the pawl from the aperture.
It is also to be appreciated that the operation of the present invention does not depend upon any particular orientation of the complete buckle assembly. Thus, although the terms "upward" and "downward" have been used in the description of the preferred embodiment, those terms are illustrative of the operation in standard, preferred configurations. The entire assembly could be inverted so that the "top" button was located on the bottom without adversely affecting the operation of the invention. Alternatively, the pawl and lever arm portions could be inverted while leaving the buttons in their preferred locations. In either of these inverted configurations the pawl would be biased upward to engage the tongue aperture, and would be pulled downward by the lever arms to disengage the pawl.
In addition, it is to be appreciated that the buckle of the present invention requires less force to lift the pawl from its aperture than is required by traditional, ramped designs. This is because the levers are more mechanically efficient than ramps which must expend significant energy overcoming the frictional forces between the ramp and the pawl. It is further to be appreciated that the force required to lift the pawl with the present invention depends, in part, on the length of the lever arm. The longer the effective length of the lever arm, the less force is required to move a given load.
Finally, it is to be appreciated that the buckle of the present invention provides a buckle which is more resistant to wear, and therefore more consistent in operation over the life of the buckle. In particular, the buckle of the present invention is resistant to developing rough spots or hitches which may inhibit the smooth and easy operation of the buckle. As was stated previously, the friction on the button ramps is a significant cause of ramp wear, and accordingly a significant cause of inconsistent operation over time. Because the pawl levers of the present invention assist in lifting the pawl from the aperture, wear on the button ramps is reduced, and the smoothness and consistency of the buckle's operation over time is enhanced.
Obviously, a large number of variations are contemplated and may be included to adapt the buckle of the present invention to a particular need without changing the basic design. Therefore, while the invention has been illustrated and described in detail in the foregoing drawings and descriptions, the same are to be considered illustrative and not restrictive in character. It is to be understood that the preferred embodiments have been shown and described, and that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims

A buckle fastener to engage a tongue, comprising:
(a) a frame;

(b) a pawl, movably mounted on said frame, to engage a tongue;

(c) a pawl lever to disengage said pawl from said tongue;

(d) a fulcrum to cooperate with said pawl lever;

(e) means to pivot said pawl lever on said fulcrum.
A buckle fastener according to claim 1, wherein said pawl lever includes a pawl blocking portion to prevent the pawl from disengaging the tongue unless the lever has been pivoted on its fulcrum.
A buckle fastener according to claim 2, wherein said pawl blocking portion includes an indent to prevent the pawl from disengaging the pawl block while the pawl block is in its blocking position.
A buckle fastener according to claim 1, and further including means to bias said pawl to its engaged position.
A buckle fastener according to claim 1, and further including a housing to substantially enclose the buckle fastener.
A buckle fastener according to claim 5, and further including a push button, slidably received in said housing, to activate said means to pivot said pawl lever on its fulcrum.
A buckle fastener according to claim 6, and further including one or more ramps, attached to said push-button, to assist in disengaging said pawl from said tongue aperture.