US3863303A

US3863303A - Connector buckle

Info

Publication number: US3863303A
Application number: US414384A
Authority: US
Inventors: Daniel A Armstrong; Michael A Pocobello
Original assignee: American Safety Equipment Corp
Current assignee: American Safety Equipment Corp
Priority date: 1973-11-09
Filing date: 1973-11-09
Publication date: 1975-02-04
Anticipated expiration: 1992-02-04

Abstract

A buckle comprises a buckle body and a cam rotatably mounted at one end of the buckle body. A support plate with an aperture at one end thereof is pivotaly mounted along one side of the buckle body. When the support plate is pivoted to its closed position, the aperture or bearing on the support plate helps support the cam. When the support plate is in the upper position away from the side of the buckle body, seat belt webbing can be inserted between the cam and the buckle body. The cam is so configured that a force pulling on one end of the webbing causes the side of the cam on the side on which the webbing force is applied to move away from the buckle body, and consequently the other side of the cam moves up toward the buckle body, whereby the webbing which is between the cam and the buckle body is gripped by the cam surface and an extension of the buckle body. Another extension of the buckle body is on the other side of the cam and the cam is symmetrical so that a force on either side of the cam by either end of the webbing will function to grip the webbing between the cam and an extension of the buckle body.

Description

United States Patent 1191 Armstrong et al.

1 1 Feb. 4, 1975 1 1 CONNECTOR BUCKLE [73] Assignee: American Safety Equipment Corporation, New York, NY.

221 Filed: Nov. 9, 1973 [211 App]. No.: 414,384

[52] U.S. Cl 24/193, 24/134 KB [51] Int. Cl A441) 11/12 [58] Field of Search 24/193, 170, 134

[56] References Cited UNITED STATES PATENTS 718,710 1/1903 Houghton 24/170 891,365 6/1908 Pawolowski 24/134 P 1,793,330 2/1931 Magnant 24/133 2,076,940 4/1937 Fair 2,226,020 12/1940 Rowe 2,903,774 9/1959 Harley .1 3,510,151 5/1970 Weman 24/170 FOREIGN PATENTS OR APPLlCATlONS 707,337 7/1931 France 24/134 P 686,380 l/l953 Great Britain 24/170 751,051 6/1956 Great Britain 24/193 Primary Examiner-Bernard A. Gelak Attorney, Agent, or FirmMiketta, Glenny, Poms & Smith [57] ABSTRACT A buckle comprises a buckle body and a cam rotatably mounted at one end of the buckle body. A support plate with an aperture at one end thereof is pivot aly mounted along one side of the buckle body. When the support plate is pivoted to its closed position, the aperture or bearing on the support plate helps support the cam. When the support plate is in the upper position away from the side of the buckle body, seat belt webbing can be inserted between the cam and the buckle body. The cam is so configured that a force pulling on one end of the webbing causes the side of the cam on the side on which the webbing force is applied to move away from the buckle body, and consequently the other side of the cam moves up toward the buckle body, whereby the webbing which is between the cam and the buckle body is gripped by the cam surface and an extension of the buckle body. Another extension of the buckle body is on the other side of the cam and the cam is symmetrical so that a force on either side of the cam by either end of the webbing will function to grip the webbing between the cam and an extension of the buckle body.

4 Claims, 18 Drawing Figures PAIENIEO 3, 863 .303

sum 2 or 4 1 CONNECTOR BUCKLE CROSS REFERENCE TO RELATED APPLICATIONS This application relates generally to application Ser. No. 414,192, filed Nov. 9, I973, to Daniel Armstrong, entitled, Child Safety Seat."

BACKGROUND OF THE INVENTION This invention generally relates to a buckle which is permanently yet adjustably connected to seat belt webbing for connection to other seat belt webbing.

When child safety seats are positioned on a seat of a vehicle, it is necessary to anchor them in place. Application Ser. No. 4l4,l92, supra, discusses the advantages of having a plastic molded seat supported by a tubular frame, and having auxiliary straps to anchor the supporting tubular frame to the vehicle seat belt.

The prior art teaches differing modes for attaching a child safety seat to the vehicle. Kindelberger US. Pat. No. 2,664,140, dated Dec. 29, 1953, provides a specially designed strap which connects to the child safety seat and which must be separately secured to the floor of the vehicle. The Kindelberger device is also provided with a buckle 27 to adjust a strap attached to part of the seat. Jakob, U.S. Pat. No. 3,709,558, issued Jan. 9, I973, teaches a pair of D-rings on either side of a child safety seat which grip the existing vehicle lap belts to secure the child safety seat. Lucas, US. Pat. No. 3,186,762, dated June l, I965, teaches a mode of attaching the seat belt of a child safety seat to respective vehicle seat belts. Lastly, Cicero, U.S. Pat. No. 3,606,453, dated Sept. 20, 1971, anchors his child safety seat by passing the regular automobile seat belt through slots on either side of the seat. The automobile seat belt is buckled in a normal fashion between the slots and tightened to anchor the child safety seat.

It is advantageous to provide a buckle on the end of the auxiliary belt which can easily be connected to the seat belt of the vehicle. Of course, a quick connection would be to provide a buckle on one auxiliary strap which would be compatible with the tongue plate of the vehicle belt and on the other side to provide a tongue plate on the auxiliary belt which would be compatible to the vehicle seat belt buckle. Because different vehicle seat belts have different shaped buckles, if the child safety seat were to be used in different vehicles, the buckle and tongue plate added to the auxiliary belt would have to be changed for each different type of vehicle seat belt. Therefore, a connector buckle on the auxiliary straps which will grip the webbing of the seat belt instead of being attached to the buckle or tongue plate of the seat belt offers many advantages.

In Ser. No. 227,469, filed Feb. 18, I972, to Roberts et al, it is taught to attach an anchoring belt to the webbing of the vehicle seat belt. However, the seat belts must be passed correctly through a slot on the tongue plate which can be a time-consuming project.

BRIEF DESCRIPTION OF THE INVENTION Therefore, it is a primary object of this invention to provide a novel buckle for connecting two straps together. An additional object of the invention is to provide a buckle which, when attached to one end of a strap, will allow rapid connection to another strap. It support a further object that this connection be quickly made at any point along the webbing and should be such a connection that the person making the connection does not have to plan which way the webbing goes through the buckle. It is also an object to provide a buckle which, if threaded backwards" through the buckle, will still function correctly and therefore be foolproof."

Generally, the improved buckle comprises a buckle body, and a cam which is pivotably connected to the buckle body at an axis of rotation. Extensions from the buckle body on both sides of the axis of rotation of the cam limit pivotal movement of the cam. A suppoprt plate, which is pivotally connected along one side of the buckle body and is normally perpendicular to the axis of rotation of the cam, is provided with an aperture which provides a bearing to support one end of the cam. When the door plate is rotated to a second position, the bearing on the door plate is disengaged from the cam and webbing can be inserted between the buckle body and the cam. Forces applied to one end of the webbing and consequently to one side of the cam cause the other side of the cam to pinch the other side of the webbing against the buckle body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of the child safety seat anchored to the automobile seat.

FIG. 2 is a side elevation of the child safety seat of the present invention.

FIG. 3 is a front elevation of the child safety seat.

FIG. 4 is a perspective of the tray assembly which is attachable to the child safety seat.

FIG. 5 is a cross sectional view of the auxiliary strap attaching means, taken along the line V-V of FIG. 2.

FIG. 6 is the rear elevation of the improved child safety seat.

FIG. 7 is the top elevation of the improved child safety seat.

FIG. 8 is the bottom view of the improved child safety seat.

FIG. 9 is a sectional view of the tray attachment along the line IX-IX of FIG. 2.

FIG. 10 is a sectional view of the child safety seat, showing the harness attachment to the tubular frame. and is taken along line X---)( of FIG. 3.

FIG. 11 is a section view of the child safety seat showing the crotch strap adjustment and is taken along line XI-XI of FIG. 3.

FIG. 12 is a sectional view of the shoulder strap adjusting means, and is taken along line XII-XII of FIG. 3.

FIG. 13 shows a modified position of use of the shoulder straps of the harness of FIG. 12.

FIG. 14 is a side view of the buckle attaching the auxiliary straps to the automobile seatbelt webbing.

FIG. 15 is a front view of the buckle showing the auxiliary straps and the seatbelt webbing.

FIG. 16 is the other side view of the buckle shown in FIG. 14.

FIG. 17 is the rear view of the buckle.

FIG. 18 is a cross sectional view of the buckle taken aiong line XVIII-XVIII of FIG. [5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The seat body means, which is the subject of the aforesaid application Ser. No. 4l4,l92, is shown generally at 10 and in FIG. 1 is shown anchored against vehicle seat back 19. It is contemplated that the child safety seat would have its greatest applicability in use in automobiles. However, the seat could be used in connection with any vehicle having seatblets. Also in FIG. I, the child safety seat is shown anchored to a bench seat, but it could easily be anchored to a bucket" seat.

Referring to FIG. 2, the child safety seat 10 comprises generally a seat or bottom wall 11, a rear wall 12, and side walls 13. The walls of the seat body means 10 are molded plastic, high density ethylene butene copolymer. Attached to the walls of the seat body is cushioning material. The child sits on seat or bottom cushion 14, and upper cushion l surrounds the rear wall and side walls and cushions the child when he contacts a side wall 13.

A lip 16 is formed around at least a portion of the front of the walls of the seat body. The function of the lip is threefold. First, it adds rigidity to the plastic seat body. Second, it presents a rounded front edge to a child seated in the seat to lessen the chance of injury on a sharp edge. Third, formed behind the lip is a channel 17 whose function will be further explained hereinafter. The channel 17 is shown in more clarity in FIGS. 5, 6, 8 and 9.

The seat body means is supported by support means. shown generally as tubular frame 20. A tubular frame was chosen for its strength, its low weight and its ease of bending and assembly. The tubular frame comprises a horizontal bottom portion 21 and a horizontal top portion 22, shown more clearly in FIG. 6, and upright portions of the frame 23 which connect the upper and lower horizontal portions of the frame together. The upright portion 23 of the frame comprises a bottom upright portion 24 and a diagonal upright portion 25.

In order to ease the assembly of the device, the frame is made in two sections. One section contains the hori zontal upper portion of the frame and part of the upright diagonal portion. The part of the upright diagonal portion is indicated at 27. The other section of the frame consists of the bottom horizontal portion 21, the bottom upright portion 24 and part of the diagnal upright portion 25. That part of the diagonal upright portion is indicated at 26. The upper diagonal portion includes a necked-down portion of smaller diameter 28 for insertion into the end of bottom diagonal portion 26. Pin 29 passes through the top part of bottom diagonal portion 26 and its intersection with the smaller diameter portion 28 to secure the frame members together.

The upper horizontal portion of the frame fits between an upper support 30 and a lower support 31 to assist in securing the frame to the back wall of the seat body.

The harness means 40 is shown in detail in FIG. 3 and 7, and comprises generally a harness plate 41, shoulder straps 42 and crotch strap 5!. On the rear portion of harness plate 41, is an abdominal cushion 49 which surrounds the front of the infant or child.

Conventional seat harnesses are usually of the five point type, that is, two shoulder straps, crotch strap and two side belts secured at the center. However, the side belts were eliminated because the shoulder straps and crotch strap in combination with the abdominal cushion holds the child securely and the side belts would be superfluous. The child safety seat could be modified to add side belts which would be secured in a suitable manner.

The shoulder straps 42 are attached to the harness plate by shoulder securing means 44 shown in more detail in FIG. 12. A securing plate 45 is fastened to the harness plate 41 at an upper portion thereof. Belt 42 is pushed through the slot 46 on securing plate 45 then through the loop means 47 and back through the slot 46 terminating in a free end 48. The slot 46 is of such dimension that a slight drag is exerted on the belt 42. The loop means 47 is of such dimension that it cannot be pulled through the slot.

The crotch strap securing means is shown generally at 50 in FIG. 11 and includes a crotch strap 51, one end of which is looped through metal loop 53 and terminates in a sewn portion 52 to secure the strap to the loop. The crotch strap is passed through a slot 75 in the cushion and slot 74 in the bottom wall of the seat body, around horizontal bottom portion 21 of the frame, and then back through the slots in an upward direction toward the abdominal pad. The crotch strap is passed through slot on central buckle 54 and then down through the metal loop 53. It is again passed through slot 55 and terminates in a free end 56. When there is little or no tension in the webbing, free end 56 can easily be pulled to adjust the crotch strap. However, when tension is applied to the crotch strap adjusting means, as for example, during a crash, the friction on the webbing at the two loops through slot 55 prevents any slipping of the webbing.

Pin 57, having a raised portion 59 thereabout is secured to the securing plate 45. Slot 58 of central buckle 54 is large enough to pass over the raised portion 59 of pin 57. The slight forces from the webbing and from gravity on central bucklet 54 prevent the central buckle from accidental slipping from pin 57. To facilitate securing and removing of the central buckle 54 from pin 57, a buckle handle 60 is provided.

The means securing the harness to the rest of the assembly follows, and isshown in FIGS. 10, II and 13. The shoulder straps are passed through slots 71 of the cushion and slot of rear wall 12 of the seat body and around the top horizontal portion of the frame. The shoulder straps can be adjusted to accommodate a smaller child by passing the shoulder belt through lower cushion slots 73 and lower rear wall slots 72 and then around the frame. If the lower set of slots is used, the shoulder straps will better conform to the body of a small child.

In a similar manner crotch strap 51 is passed through slot in the seat cushion l4 and slot 74 in bottom wall 11. The harness straps also assist in holding the tubular frame against the seat body means.

During a crash or very sudden deceleration, the forces from the child will be applied to the abdominal pad 49. These forces will be transmitted to the shoulder straps and the crotch strap, and because these straps are looped around the tubular frame, all forces will be absorbed by the frame. The straps merely pass through slots in the walls of the seat body means, and, therefore, no force from the straps will be transmitted to the seat body. In this manner, it can be seen that the seat body means can be made of very lightweight material since it does not have to resist deformation during a crash.

To increase the rigidity of the seat while maintaining rather thin walls for lightweight construction, a system of ribs is molded with the seat body means at the rear thereof as shown in FIG. 6. Horizontal ribs 76 extend around the upper portion of the rear and side walls. Vertical ribs 77 add rigidity to the horizontal ribs 76. lt should be noted that these vertical ribs are directly above the lower seat slots 72.

Referring now to FIG. 13 when the child safety seat is being used with small children and the

lower slots

72, 73 are being used, the shoulder straps pass from the slots along the back end of the horizontal ribs 76 to the tubular frame. It is along the path of the shoulder strap from the frame to the lower slots that vertical ribs 77 are needed to help reinforce that region of the horizontal ribs 76. Vertical ribs 77 terminate at rib 79 which is just above the lower slots and does not extend to bottommost rib 78 which is below the slots so that the straps can pass between

ribs

77 and 78 to the lower slots.

A tray 90 is attachable to the child s safety seat. The tray consists of a flat tray surface 95 and downwardly extending flanges 91. Formed on each flange 91 is a pin 92 which tits in hole 93 in each sidewall 13. Each sidewall 13 is provided with a recess 94 into which flanges 91 fits so that tray 90 is prevented from rotating. See FIG. 9.

As shown in H6. 2, part of the bottom diagonal portion 26 of the tubular frame rests within channel 17 of the seat body means. As shown in H0. 5, auxiliary belt 81, which is attached to the vehicles seatbelt in a manner described hereinafter, passes through a slot 82 on the lip portion 15 of each sidewall 13. It is looped around bottom diagonal portion 26 of the tubular frame then passes back through the slot 82 where the short end is sewn to the long end of strap 81 at sewn together portion 83. it should be noted that auxiliary strap 81 is secured to the bottom diagonal portion 26 of the tubular frame within channel 17 of the seat body means and assists in maintaining the seat body means and the tubular frame together. This arrangement is also shown in FIGS. 6 and 8.

The auxiliary belt 81 tightly restrains the child seat on the vehicle seat. When a child is seated on the child safety seat, the system has a center of gravity indicated as CG in H08. 1 and 2. Referring particularly to FIG. 2, it should be noted that the connection 84 between auxiliary belt 8] and the tubular frame is above and in front of the center of gravity of the assembly. in a crash situation, the dynamics of the system are such as to cause the center of gravity to move in a counterclockwise rotation about the belt anchoring location 84. This rotation balances a rotation in the opposite direction about the horizontal bottom portion 21 of the frame which is caused by the center of gravity being above the horizontal bottom portion 21 of the frame which is resting on the vehicle seat 18. This balance of moments result in a near horizontal ride-down" of the seat minimizing the frontal excursion of the child.

In a lateral impact, shown in FIG. 1, since the center of gravity of the child and the seat assembly is behind the point of attachment 84 the seat will tend to rotate, turning the seat back in the direction of the impact, therefore containing the child within the seat. Therefore, it is important to anchor the auxiliary strap 81 forward and above the center of gravity of the assembly. It should also be noted that the auxiliary strap is anchored to the tubular frame and not to the plastic seat body means. Therefore, forces transmitted to the child safety seat are absorbed by the tubular frame and not the plastic seat body.

in order to make the seat body means of the aforesaid application Ser. No. 414,192 compatable with different vehicles, it is preferable to provide an assembly which can be permanently attached to the end of auxiliary strap Bl, and which will grip the webbing of a vehicle seatbelt. This design is necessitated by the fact that different vehicles might have different buckles on the seatbelts of the vehicle. To make the seatbelt compatable with each different buckle would require different gripping means for each seatbelt buckle. However, the instant invention grips the webbing of the existing behicle seatbelts in a manner set forth below. The gripping means consists of a buckle body shown generally as element 110. The buckle body consists generally of a front face 112, a rear face 113, and a side face 114 on one side of the buckle body. A fixed axle support 111 depends from the side face 114. On the other side of the buckle body is side plate 115 and lateral stops or guides 116, whose function will be described hereinafter. Cam means, shown generally at is pivotally connected to the buckle body by having an extended portion of the cam act as an axle through bearing 131 on fixed axle support 111.

As shown in FIG. 18, webbing 157 of the car seatbelt passes over the cam means 120. In order to insert the seatbelt webbing over the cam, the buckle body is provided with means to allow insertion of the webbing 140. The means to allow insertion of the webbing 140 consists of a pivotable support plate 141, which is pivotally connected by pivots 144 through bearings M3 on pivot plates 142 of front face 112 and rear face 113 of the buckle body. Spring [45 biases the support plate 141 in a direction clockwise about pivot 144 in FIG. 17. Aperture in plate 141 provides a movable support means or bearing for one end of cam 120. When the support plate 141 is in the closed position as shown in FIG. 15, the shaft end 128 of the cam 120 is pivotally mounted and restrained within removable support means or bearing aperture 130. To facilitate opening and closing of the support plate Ml, shaft end 128 has a rounded portion 129 to easily fit into bearing aperture 130.

When the webbing is inserted between the cam and the buckle body, it assumes a configuration shown generally at FIG. 18. The cam shape is an important feature of the present invention and is best seen in FIG. 18. Specifically, the cam consists of a cylindrical surface 120. In the preferred embodiment, the surface is circularly cylindrical but other curves could be chosen. The circularly cylindrical shape of surface 120 is extended as the shaft ends fitting into the

bearings

130 and 131. The circularly cylindrical surface extends more than half way around the axis 132 of the cam. From both sides of the circularly cylindrical portion of the cam, extend two cam clamping or pinching

surfaces

121 and 123. A plane extending from these surfaces should preferably intersect the axis of rotation 132.

Extending downward from the front face 1 l2 and the rear face 113 are

buckle gripping surfaces

127 and 126 respectively. As shown in FIG. 18, the application of a force due to vehicle impact or the like on car seatbelt webbing 157 away from the buckle will cause rotation of the cam means 120 about axis rotation 132. Cam surface 123 moves upward until it contacts the free end of webbing 128 and grips it at buckle gripping surface 127. The buckle gripping surface 127 is so positioned that cam surface 123 will be parallel to the bottom edge of buckle gripping surface 127 when they are separated by the thickness of seatbelt webbing 128 to present the greatest area of the gripping surface and the cam surface to the webbing, This assists in gripping the webbing. Depending on the location of

buckle gripping surfaces

126 and 127, the orientation of the cam pinching or clamping

surfaces

121 and 123 can be modified. From these

clamp pinching surfaces

121 and 123 extend cam extension surfaces 122 and 124. By having these extension surfaces, a force applied by pulling on seatbelt webbing 157 supplies a greater moment about axis 132, which results in a greater force applied to the loose end of seatbelt webbing 158 by the gripping sur faces 123 and 127.

It should be noted at this point that it does not matter that the webbing of the seatbelt 157 be inserted only in the manner shown in H0. 18. if the washing were reversed so that free end 158 of the webbing were actually the end on which force was applied, cam 120 would be pivoted counter-clockwise about axis 132 to grip the webbing between

gripping surfaces

121 and 126.

Therefore, it does not matter which end of the webbing is anchored to the vehicle. The devices is almost foolproof."

In order to maintain plate 141 and bearing 130 aligned with fixed support 111 and perpendicular to the

cam axle

128 and 125, lateral stops or guides 116 extend from the front face 112 and the rear face 113 of the buckle body. Side plate 115 with slot 117 fits over the lateral stops 116. Support plate 141 rests against the side plate 115 to maintain the plate 141 in a position shown in FIG. 15. Lateral guides 116 assist in maintaining the support plate from moving in a side-toside direction as shown in FIG. 14.

The buckle assembly is adjustable by way of buckle adjustment means 150, shown in FIG. 18. The buckle adjustment means consists of a slidebar 151 slideably attached to the buckle body. The extension of auxiliary belt 81 is shown at 155. The belt portion 155 passes through slot 152, around slidebar 151 and back through slot 152. The free end of the belt 156 passes by tang 154. A force pulling on belt 155 will slide the slidebar 151 so that the belt contacts cinch point 153 to secure the belts. Tang 154 is properly positioned so as to compensate for the different force vectors caused by opposite rotation of cam means 120.

it will thus be seen that the improvement of the present invention described in its exemplary form, meets all of the aforementioned objects to provide a novel structure whose definition is limited only by the following claims.

We claim:

1. In a device for connecting webbing to a buckle including a buckle body with limiting means mounted thereto, and cam means mounted on said buckle body, said cam extending longitudinally for engaging the width of the webbing between itself and the limiting means, the improvement comprising the provision of:

first supporting means on said buckle body for supporting one longitudinal end of said cam means for pivoting movement about its longitudinal axis and permitting movement of said longitudinal axis through an arcuate path;

second supporting means associated with said buckle body and movable between a first position for supporting said other longitudinal end of said cam means for pivoting movement of said cam means about said longitudinal axis and preventing arcuate movement of said longitudinal axis of said cam and to a second position releasing said end of said cam and permitting the axis to move in said arcuate path whereby when said second supporting means is in its second position, said webbing being insertable between said cam and said limiting means when said cam is moved in an arcuate path, and when said second supporting means is in its first position, said webbing is prevented from being removed from between said cam and limiting means whereby pulling on an end of the webbing causes said webbing to pivot said cam means about said longitudinal axis to grip the webbing between said limiting means and said cam means.

2. The improvement of claim 1, further including the provision of said second support means being pivotally connected to said buckle body between its first position and second position.

3.1n the device of claim 1 wherein said cam includes a central portion and two transverse portions on opposite sides of said central portion from each other, said limiting means further including a pair of gripping surfaces for gripping said webbing between said cam and either of said gripping surfaces, the improvement further including the provision of cam extension surfaces on each side of said cam extending transversely past both gripping surfaces to increase the moment of force from said webbing on one side of said cam to increase the force from said cam on the webbing between the other side of said cam and the gripping surface.

4. The improvement of claim 1 further including the provision of having said cam including a cylindrical surface about the longitudinal axis of rotation of said cam. said cylindrical surface extending a substantial angle more than half way about said axis of rotation, two first planar surfaces intersecting said cylindrical surface, and wherein the plane of said first planar surfaces in cludes said longitudinal axis of rotation of said cam, said first planar surfaces acting as clamping means to clamp the webbing between one of said first planar surfaces and said limiting means on said buckle body upon pivoting of said cam, and two second planar surfaces intersecting said first planar surfaces to extend the moment arm of force applied to the cam on one side of the longitudinal axis of rotation whereby a large force is transmitted to said clamping means for clamping said webbing at said limiting means on the other side of said longitudinal axis of rotation.

Claims

1. In a device for connecting webbing to a buckle including a buckle body with limiting means mounted thereto, and cam means mounted on said buckle body, said cam extending longitudinally for engaging the width of the webbing between itself and the limiting means, the improvement comprising the provision of: first supporting means on said buckle body for supporting one longitudinal end of said cam means for pivoting movement about its longitudinal axis and permitting movement of said longitudinal axis through an arcuate path; second supporting means associated with said buckle body and movable between a first position for supporting said other longitudinal end of said cam means for pivoting movement of said cam means about said longitudinal axis and preventing arcuate movement of said longitudinal axis of said cam and to a second position releasing said end of said cam and permitting the axis to move in said arcuate path whereby when said second supporting means is in its second position, said webbing being insertable between said cam and said limiting means when said cam is moved in an arcuate path, and when said second supporting means is in its first position, said webbing is prevented from being removed from between said cam and limiting means whereby pulling on an end of the webbing causes said webbing to pivot said cam means about said longitudinal axis to grip the webbing between said limiting means and said cam means.

3. In the device of claim 1 wherein said cam includes a central portion and two transverse portions on opposite sides of said central portion from each other, said limiting means further including a pair of gripping surfaces for gripping said webbing between said cam and either of said gripping surfaces, the improvement further including the provision of cam extension surfaces on each side of said cam extending transversely past both gripping surfaces to increase the moment of force from said webbing on one side of said cam to increase the force from said cam on the webbing between the other side of said cam and the gripping surface.

4. The improvement of claim 1 further including the provision of having said cam including a cylindrical surface about the longitudinal axis of rotation of said cam, said cylindrical surface extending a substantial angle more than half way about said axis of rotation, two first planar surfaces intersecting said cylindrical surface, and wherein the plane of said first planar surfaces includes said longitudinal axis of rotation of said cam, said first planar surfaces acting as clamping means to clamp the webbing between one of said first planar surfaces and said limiting means on said buckle body upon pivoting of said cam, and two second planar surfacEs intersecting said first planar surfaces to extend the moment arm of force applied to the cam on one side of the longitudinal axis of rotation whereby a large force is transmitted to said clamping means for clamping said webbing at said limiting means on the other side of said longitudinal axis of rotation.