WO2010076615A1

WO2010076615A1 - Ratchet buckle with c-shape bar

Info

Publication number: WO2010076615A1
Application number: PCT/IB2009/005079
Authority: WO
Inventors: Weiguo Chen
Original assignee: Weiguo Chen
Priority date: 2008-12-29
Filing date: 2009-03-05
Publication date: 2010-07-08

Abstract

A tie-down provides an adjustable strap under control of a ratchet during retraction and pay-out. The tie-down is provided with a strap (96) issuing rearward from a transverse bar (90) between base sides (11), the bar (90) being an integral part of a base (10) of the tie-down, three sides having been rolled up from the base bottom (12) into a C-shaped bar opening rearward. A forward strap issues forward from the tie-down secured to a spindle (40) to which ratchet wheels (50) attach. The forward strap wraps the spindle (40) during tie-down strap retraction.

Description

RATCHET BUCKLE WITH C-SHAPE BAR

BACKGROUND Field of the Invention

This invention relates to tie-downs, as may be used to secure a load to a vehicle.

Prior Art It is known to have a tie down assembly that secures a load to a vehicle. Typical is that tie-down assembly disclosed by Anthony et al. in U.S. Pat. No. 5,282,706 in which Anthony et al. describes an assembly secured directly to a chassis with a strap issuing therefrom for connection around or to a load. The strap is wrapped around a spool and unwound on release to pay out as necessary. When the strap is secured about the load, the strap is released and it automatically retracts around the spool. The strapping apparatus, U.S. Pat. No. 7,350,767 is also known. Other prior art references are also known, these references being only typical. SUMMARY OF THE INVENTION The ratchet-based tie-down of the present invention features a spindle as a ratchet spool without a retraction spring. In a pay out configuration, a forward directed strap simply unwinds from the spool under user pulling action, without spring bias to rewind. A rearward directed strap extends from the tie-down without length adjustment to assure against slippage in length of the rearward directed strap. Without a retraction spring; when the spindle not connected to anchor points under strap tension, the spindle remains in payout unless and until it is positively rewound by a user onto the spindle.

A forward hold on the base holds a ratchet crank out of engagement with a ratchet wheel, allowing the spindle to rotate freely. A rearward hold on the base holds the crank in a locked position in which the crank captures a locking plate when the locking plate is engaged with the teeth of the ratchet wheel, preventing the ratchet wheel from rotating, thus holding straps of the tie-down taut to forward and rearward anchor points to which they may be attached, respectively. As in ratchet based tie-downs of the prior art, a ratchet spool, or instead in this instant configuration, a spindle without a retraction spring, extends between sides of a tie-down base. Particular to this instant configuration, the spindle comprises two semi-cylindrical halves with opposing diametric surfaces slightly spaced apart. Ends of each of the halves extend through matching holes on each side of the ratchet wheels therein providing a heavy-duty link between the wheels and the crank.

The spindle halves continue through the crank sides and through matching holes in base sides, thus connecting the base sides and crank sides rotationally about the spindle. The tie-down is configurable between a pay-out mode or configuration and a retraction, or ratchet, configuration. With the tie— down assembly in pay-out mode the user simply pulls the strap out without a counter bias from a retraction spring as it unwinds from a spindle, or spool.

The strap is tightened to a load when the tie-down is moved to its retraction mode. Reconfiguration between modes requires positive action by the user so there is no inadvertent switch between operation modes. In retract mode, a crank is repeatedly lifted and lowered in effecting a ratcheting of the spindle rotation in strap retraction. A ratchet plate engages teeth of a ratchet wheel attached to the spindle to secure the spool from releasing when the crank is lowered in normal ratcheting retraction operation to engage a new pair of ratchet teeth on the ratchet wheels. A lock plate engages the ratchet wheel teeth to lock against rotation of the ratchet wheel, taking the ratchet wheel out of ratcheting operation. To return the ratchet wheel to ratchet operation, the crank is lifted forward into operation position which releases the lock plate from ratchet teeth. A cam on the crank also moves the lock plate away from the ratchet wheel as the crank is moved forward allowing the ratchet wheel to freely rotate through the ratcheting mechanism.

The tie-down is changed from ratchet mode to pay-out mode by moving the crank forward over a forward hold that is beyond a normal ratcheting range of motion locking the crank forward as the ratchet plate and the lock plate are both withdrawn from the ratchet wheel allowing it to rotate freely. Thus, in pay-out mode the strap is pulled by the user without restriction. A further feature of the invention incorporates the rearward strap attached rearward on the base on a base buckle that includes a "C shaped" bar transverse the tie-down between base sides. This is a design feature that is an improvement over a bolt and nut typical of the prior art in that its C shaped structure provides an enhanced strength and flexural resistance much improved over a bolt and nut configuration where the strap passes over a nut transversely attached to base sides by nuts . The bar is formed by stamping three sides of a generally rectangular shape out of the base bottom and further including attachment ears on cut corners that connect to the base sides. The three sided rectangular is then rolled from the base bottom back toward the uncut rectangular side forming the C shaped opening rearward with the ears secured into matching holes in the base sides. This rear strap bar structure then improves the tie down structure by simplifying the design and configuration and inherently reduces failure of the tie down from breakage of parts as parts are eliminated, which also helps reduce construction cost. It also provides an increase in strength by the rear strap bar being unitary with the base bottom.

BRIEF DECRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the tie down of FIG. 1 .

FIG. 2 is an exploded isometric view of the tie down of the present invention.

FIG. 3 is a bottom view of the tie down of FIG. 2. FIG. 4 is a side view of the tie down of FIG. 2.

FIG. 5 is a perspective view of the base of the tie down of FIG. 2 FIG. 6 is a side section view of the base of FIG. 2 showing the connection of the rearward strap to the base. FIG. 7 is a top planar view of the base of the present invention prior to it being stamped and folded. FIG. 8 is a cut-away perspective view of the rear strap bar.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The tie down 1 of the present invention comprises a base 1 0 and a crank 30 mutually pivoting at a spindle 40 by a ratchet action. The base 1 0 includes opposing base sides 1 1 upstanding from a base bottom 1 2, each side 1 1 having a base spindle hole 1 3 for receiving the spindle 40 that rotates coaxially within the base spindle holes 1 3 between the base sides 1 1 . The crank 30 includes crank sides 31 spaced apart by a spacer 32 that extends intermediate the length of each of the crank sides 31 between the crank sides 31 . Crank sides 31 partially overlap the base sides 1 1 outside the base sides 1 1 as the base sides 1 1 and the crank sides 31 mutually pivot at the spindle. A crank handle 32 extends between crank sides 31 rearward in the crank 30. The crank 30 also has a pair of crank holes 33 on respective crank sides 31 aligned with the base holes 1 3 such that the spindle 40 passes rotatably through the aligned holes 1 3, 33. A ratchet wheel 50 is located between respective base 1 1 and crank sides 31 align coaxially with the spindle 40 and aligned base spindle and crank holes 1 3, 33 and orthogonal to the base and crank sides 1 1 , 31 .

The spindle 40 is forward in the tie-down and comprises two half spindles 41 a, 41 b disposed with opposing diametric faces 42 spaced apart. Ends 43 of each half spindle 41 a, 41 b fit into matching semi circular holes 51 in the respective ratchet wheels 50 with each semi circular hole 51 receiving a half spindle end 43 such that as the crank 30 rotates the ratchet wheels 50, the spindle 40 also rotates. The half spindles 41 a, 41 b are held in place in the semi-circular holes 51 by pins 44 passing through pin holes 45 in ends 46 of the half spindles 41 a, 41 b.

A forward strap 60 wraps around the spindle 40, for example with a forward strap end 61 passing between the half spindles 41 a, 41 b to bind the forward strap 60 to the spindle 40 such that as the crank 30 rotates the forward strap 60 further wraps or unwraps the spindle 40.

The tie-down functions in the normal manner of a ratchet to controllably rotate the spindle. In implementing the ratchet 70, each crank side 31 has a crank through side slot 34 angled radial to the spindle 40. A ratchet plate 71 extends between the crank sides 31 (and over the base sides 1 1 ) disposed to engage both ratchet wheels 50 at respective crank sides 31 . The ratchet plate 71 is withdrawn from engagement with ratchet teeth 72 by a user's pull of a ratchet release 73 that is connected to the ratchet plate 71 . Typically, the ratchet release 73 and the ratchet plate 71 are a single piece with opposite ends defining the ratchet plate 71 and the ratchet release 73. Ends of the ratchet plate

71 fit slidably in a radial direction with respective to the spindle 40 in respectively crank side slots 34, into and out of engagement with the ratchet teeth 72. The ratchet plate 71 is disposed to be pulled radially outward by action of the ratchet release 73 or released radially inward under bias of a first spring 75. Thus, sliding the ratchet plate 71 inward through the crank side slots 34 causes the ratchet plate 71 to engage the ratchet teeth 72. Similarly, sliding the ratchet plate 71 outward through the crank side slots 34 causes the ratchet plate 71 to disengage from the ratchet teeth 72, therein allowing the crank to rotate with the ratchet plate 71 outside of the ratchet teeth72.

With the crank 30 rotated rearward generally, the ratchet plate 71 may be pulled further outward, also radially, and lifted over a rearward hold 1 5 that is on an upper edge 1 6 of each respective base side 1 1 to a rotational position 1 7 behind the rearward hold 1 5 on the edge 1 6 of the base side 1 1 therein preventing the crank 30 from rotating until the crank side 31 is lifted back over the rearward hold 1 5 to rest on the edge

1 6 of the base side 1 1 forward of the rearward hold 1 5. To effect a ratchet wheel lock, a lock plate 80 is provided in the base 1 0, extending between base sides 1 1 and passing through base slots 1 7. As with the crank slots, the base slots 1 5 are directed radially to the spindle 40 and ratchet wheels 50 below the crank 30. As the crank 30 is rotated rearward with the ratchet plate 71 rearward of the rearward hold 1 5, a notch 36 in the respective crank sides 31 engage the lock plate 80 in the lock plate lock position 81 , that is, with the lock plate 80 engaging the ratchet teeth 72, thus preventing the lock plate 80 from moving rearward out of engagement with the ratchet teeth 72. In the lock position 81 , the ratchet wheels 50 and thus the spindle 40 are prevented from rotating. The lock plate 80 is released by lifting the crank 40 such that the notch 36 does not engage the lock plate 80. A lock spring 82 continues to bias the lock plate 80 into engagement with the ratchet teeth 72. As the crank 30 is further lifted and the ratchet release 73 is pulled backward as the crank 30 is rotated forward to a forward side 1 8 of the rearward hold 1 5, a cam 19 forward on the crank respective sides 31 engages the lock plate 80 and moves the lock plate

80 rearward out of engagement with the ratchet teeth 72. The cam 1 9 continues to move the lock plate 80 away from the ratchet teeth 72 as long as the ratchet plate 71 is forward of the rearward hold 1 5. In the reverse crank motion, the cam 1 9 releases from engagement with the lock plate 80 allowing the lock plate 80 under spring bias to engage the ratchet teeth 72 as the lock plate 80 is received into the notch 36. The notch 36 is prevented from engaging the lock plate 71 except when the crank 30 is lowered rearward of the rearward hold 1 5.

With the ratchet 70 thus enabled, as the crank 30 is lowered, the ratchet plate 71 continually slides over the ratchet teeth 72 from one pair of teeth 72a on respective ratchet wheels 50 to a subsequent pair of teeth 72b. When the crank motion is reversed the ratchet plate 71 engages the ratchet teeth 72 and rotates the ratchet wheels 50 as the crank 30 is moved forward relative to the base 1 0 in the normal method of ratcheting. A forward hold 20 is located forward on respective base side edges

1 6. The ratchet plate 71 may be pulled by the ratchet release 73 radially away from the ratchet teeth 72 and over the forward hold 20 on each base side 1 1 into engagement with a forward notch 21 on the forward side 22 of the forward hold 20 radially outward from the ratchet teeth 72 thus preventing the ratchet plate 71 from engaging the ratchet teeth 72. With the crank 30 forward, the cam 1 9 continues to maintain the ratchet plate 71 and the lock plate 80 disengaged from the ratchet teeth 72. Thus, the spindle can rotate freely, normally unwinding.

To effect a tie-down tightening action, as noted above the forward strap 60 is secured around the spindle, the forward strap 60 extending forward. Further, a rearward strap 62 is secured to the tie-down, extending rearward. As the spindle 40 is rotated as described above the effective combined strap length is extended or shortened, which combined strap comprises the forward and rearward straps 60, 63 joined by the tie-down therebetween. A rear strap bar 90 is cut out of the base bottom 1 2 by three sided stamping. The bar 90 is then rolled from the base bottom 1 2 leaving a hole 95. The bar 90 is rolled upward from the base bottom 1 2 about a uncut fourth side 94 that remains integral with the base 1 2. The bar includes ears 91 on each bar end 92 that fit into bar receiving holes 93 in the base sides 1 1 that are of size to receive the ears 91 as base sides 1 1 are bent upward from the base bottom 1 2 on each base side 1 1 which provides attachment of the bar 90 to the base bottom 1 2. With the ears in the rear strap bar 90 received into bar receiving holes 93, the rear strap bar 90 is prevented from moving further rearward past the bar receiving holes 93 under pull of the rear strap 96 under load. The rear strap 96 secures to the rear strap bar 90 by entering around the rear strap bar 90 through a hole 95 in the base bottom 1 2 and then wrapping around the rear strap bar 90 and back upon the rear strap 96 to which it is affixed therein securing the rear strap against slippage in length under load in its securement to the rear strap bar 90. and secures the rear strap 96 against slippage in length in its securement to the rear strap bar 90. In summary, then the invention disclosed herein comprises

A tie down including a base and a crank mutually pivoting at a spindle by a ratchet action, the base including opposing base sides upstanding from a base bottom, each base side including a ring and having a base spindle hole in each ring for receiving the spindle, which spindle rotates within the base spindle holes between the base sides, the crank including crank sides spaced apart and further including a crank handle extending between crank sides, the crank having a pair of crank holes on respective crank sides that are aligned with the base holes together with ratchet wheels with ratchet teeth at each spindle end such that the spindle passes rotatably through the aligned crank and base holes, the tie down adapted to receive a forward strap in attachment to the spindle to extend forward from the tie down and adapted to receive a rearward strap in attachment to the base to extend rearward from the tie down such that as the crank is rotated forward with the base and crank pivoting apart in cooperation with the ratchet action, the effective length of the combined forward and rearward straps is reduced, the improvement comprising: a rearward lug rearward on and projecting outward from said curvilinear outer edge, a ratchet plate slidable in respective crank side slots directed toward the ratchet wheel, the ratchet plate extending between the crank sides and including a ratchet plate leg portion disposed to releasably engage and disengage from teeth of the ratchet wheels, the ratchet plate leg portion movable between a ratchet condition forward of the lug and a lock condition rearward of the lug, wherein the ratchet plate moves generally along the outer edge during said ratchet action with the ratchet plate in said ratchet condition wherein movement of the ratchet plate between said ratchet and lock conditions is effected by lifting said ratchet plate leg portion over said rearward lug and wherein the crank is prevented from rotating when said ratchet plate is in lock condition, a lock plate slidable in respective base side slots directed toward teeth of the ratchet wheel, the lock plate extending between the crank sides and including a lock plate leg portion disposed to releasably engage teeth of the ratchet wheels, preventing the ratchet wheel from rotating rearward as the ratchet plate disengages from said teeth and said crank and ratchet plate rotate rearward with the base and crank pivoting together in said ratchet action, wherein at least one of said crank sides has a notch such that with the lock plate in engagement with the teeth, as the crank with ratchet plate lowers into said lock position, the lock plate is received into said notch, preventing the lock plate from disengaging from the teeth and thus the ratchet wheel from rotating. a forward lug forward on and projecting outward from said curvilinear outer edge, a cam on the crank sides moving the lock plate out of engagement with the ratchet teeth when the rotating plate in the crank is rotated over and forward of the forward lug from said ratchet condition to a forward position wherein the ratchet plate is supported out of engagement with the said teeth and wherein movement of the ratchet plate between said ratchet condition and said forward position is effected by lifting said ratchet plate leg portion over said forward lug, wherein with the crank with ratchet plate in forward position the spindle can rotate freely with the ratchet plate and the lock plate out of engagement with the teeth the ratchet wheel, a rear strap bar attached between the base sides, the rear strap bar being unitary with the base bottom being bent therefrom on a strap bar side that remains integral with the base, wherein the rear strap bar comprises an ear on each rear strap bar side that fits into a rear strap bar receiving hole in each base side, the respective rear strap bar receiving holes being of size to receive the respective ears therein preventing the rear strap bar from moving rearward past the bar receiving holes under pull of the rear strap under load, wherein the rear strap bar is adapted to receive the rear strap in securement thereto by the rear strap entering through a hole in the base bottom and then wrapping around the rear strap bar and back upon the rear strap to which it is affixed therein securing the rear strap against slippage in length under load in its securement to the rear bar, wherein the rear strap bar is formed with three sides of the rear strap bar having been cut and rolled up from the base bottom into a C-shaped bar opening rearward of the tie down, wherein the rear strap bar is formed with three sides of the rear strap bar having been cut and rolled up from the base bottom into a C- shaped bar opening rearward of the tie down, and wherein said hole in the base bottom is formed as the rear strap bar is cut and bent out of the base bottom.

Claims

Having described the invention, what is claimed is as follows:

Claims: 1 . A tie down including a base and a crank mutually pivoting at a spindle by a ratchet action, the base including opposing base sides upstanding from a base bottom, each base side including a ring and having a base spindle hole in each ring for receiving the spindle, which spindle rotates within the base spindle holes between the base sides, the crank including crank sides spaced apart and further including a crank handle extending between crank sides, the crank having a pair of crank holes on respective crank sides that are aligned with the base holes together with ratchet wheels with ratchet teeth at each spindle end such that the spindle passes rotatably through the aligned crank and base holes, the tie down adapted to receive a forward strap in attachment to the spindle to extend forward from the tie down and adapted to receive a rearward strap in attachment to the base to extend rearward from the tie down such that as the crank is rotated forward with the base and crank pivoting apart in cooperation with the ratchet action, the effective length of the combined forward and rearward straps is reduced, the improvement comprising: a rearward lug rearward on and projecting outward from said curvilinear outer edge, a ratchet plate slidable in respective crank side slots directed toward the ratchet wheel, the ratchet plate extending between the crank sides and including a ratchet plate leg portion disposed to releasably engage and disengage from teeth of the ratchet wheels, the ratchet plate leg portion movable between a ratchet condition forward of the lug and a lock condition rearward of the lug, wherein the ratchet plate moves generally along the outer edge during said ratchet action with the ratchet plate in said ratchet condition wherein movement of the ratchet plate between said ratchet and lock conditions is effected by lifting said ratchet plate leg portion over said rearward lug and wherein the crank is prevented from rotating when said ratchet plate is in lock condition, a lock plate slidable in respective base side slots directed toward teeth of the ratchet wheel, the lock plate extending between the crank sides and including a lock plate leg portion disposed to releasably engage teeth of the ratchet wheels, preventing the ratchet wheel from rotating rearward as the ratchet plate disengages from said teeth and said crank and ratchet plate rotate rearward with the base and crank pivoting together in said ratchet action, wherein at least one of said crank sides has a notch such that with the lock plate in engagement with the teeth, as the crank with ratchet plate lowers into said lock position, the lock plate is received into said notch, preventing the lock plate from disengaging from the teeth and thus the ratchet wheel from rotating. a forward lug forward on and projecting outward from said curvilinear outer edge, a cam on the crank sides moving the lock plate out of engagement with the ratchet teeth when the rotating plate in the crank is rotated over and forward of the forward lug from said ratchet condition to a forward position wherein the ratchet plate is supported out of engagement with the said teeth and wherein movement of the ratchet plate between said ratchet condition and said forward position is effected by lifting said ratchet plate leg portion over said forward lug, wherein with the crank with ratchet plate in forward position the spindle can rotate freely with the ratchet plate and the lock plate out of engagement with the teeth the ratchet wheel, a rear strap bar attached between the base sides, the rear strap bar being unitary with the base bottom being bent therefrom on a strap bar side that remains integral with the base.

2. The tie down of claim 1 wherein the bar comprises ears on each bar side that fit into bar receiving holes sized to receive the ears.

3. The tie down of claim 1 wherein the rear strap bar comprises an ear on each rear strap bar side that fits into a rear strap bar receiving hole in each base side, the respective rear strap bar receiving holes being of size to receive the respective ears therein preventing the rear strap bar from moving rearward past the bar receiving holes under pull of the rear strap under load, wherein the rear strap bar is adapted to receive the rear strap in securement thereto by the rear strap entering through a hole in the base bottom and then wrapping around the rear strap bar and back upon the rear strap to which it is affixed therein securing the rear strap against slippage in length under load in its securement to the rear bar.

4. The tie down of claim 3 wherein the rear strap bar is formed with three sides of the rear strap bar having been cut and rolled up from the base bottom into a C-shaped bar opening rearward of the tie down.

5. The tie down of claim 1 wherein the rear strap bar is formed with three sides of the rear strap bar having been cut and rolled up from the base bottom into a C-shaped bar opening rearward of the tie down.

6. A tie down including a base and a crank mutually pivoting at a spindle by a ratchet action, the base including opposing base sides upstanding from a base bottom, each base side including a ring and having a base spindle hole in each ring for receiving the spindle, which spindle rotates within the base spindle holes between the base sides, the crank including crank sides spaced apart and further including a crank handle extending between crank sides, the crank having a pair of crank holes on respective crank sides that are aligned with the base holes together with ratchet wheels with ratchet teeth at each spindle end such that the spindle passes rotatably through the aligned crank and base holes, the tie down adapted to receive a forward strap in attachment to the spindle to extend forward from the tie down and adapted to receive a rearward strap in attachment to the base to extend rearward from the tie down such that as the crank is rotated forward with the base and crank pivoting apart in cooperation with the ratchet action, the effective length of the combined forward and rearward straps is reduced, the improvement comprising a rear strap bar attached between the base sides, the rear strap bar being unitary with the base bottom being bent therefrom on a strap bar side that remains integral with the base.

7. The tie down of claim 6 wherein the rear strap bar is formed with three sides of the rear strap bar having been cut and rolled up from the base bottom into a C-shaped bar opening rearward of the tie down.

8. The tie down of claim 6 wherein the rear strap bar comprises ears on each rear strap bar side that fit into rear strap bar receiving holes sized to receive the ears therein preventing the rear strap bar from moving rearward past the bar receiving holes under pull of the rear strap under load.

9. The tie down of claim 6 wherein the rear strap bar is adapted to receive the rear strap in securement thereto by the rear strap entering through a hole in the base bottom and then wrapping around the rear strap bar and back upon the rear strap to which it is affixed therein securing the rear strap against slippage in length under load in its securement to the rear bar.

1 0. The tie down of claim 6 wherein the rear strap bar comprises an ear on each rear strap bar side that fits into a rear strap bar receiving hole in each base side, the respective rear strap bar receiving holes being of size to receive the respective ears therein preventing the rear strap bar from moving rearward past the bar receiving holes under pull of the rear strap under load, wherein the rear strap bar is adapted to receive the rear strap in securement thereto by the rear strap entering through a hole in the base bottom and then wrapping around the rear strap bar and back upon the rear strap to which it is affixed therein securing the rear strap against slippage in length under load in its securement to the rear bar.

1 1 . The tie down of claim 6 wherein said hole in the base bottom is formed as the rear strap bar is cut and bent out of the base bottom.

1 2. A tie down including a base and a crank mutually pivoting at a spindle by a ratchet action, the base including opposing base sides upstanding from a base bottom, the tie down adapted to receive a forward strap in attachment to the spindle to extend forward from the tie down and adapted to receive a rearward strap in attachment to the base to extend rearward from the tie down such that as the crank is rotated forward with the base and crank pivoting apart in cooperation with the ratchet action, the effective length of the combined forward and rearward straps is reduced, the improvement comprising a rear strap bar attached between the base sides, the rear strap bar being unitary with the base bottom with three sides of the rear strap bar having been cut and rolled up from the base bottom into a C-shaped bar opening rearward of the tie down having been bent therefrom on a strap bar side that remains integral with the base bottom wherein the rear strap bar includes an ear on each rear strap bar side that fits into a rear strap bar receiving hole in each base side, the respective rear strap bar receiving holes being of size to receive the respective ears therein preventing the rear strap bar from moving rearward past the bar receiving holes under pull of the rear strap under load, wherein the rear strap bar is adapted to receive the rear strap in securement thereto by entering through a hole in the base bottom and then wrapping around the rear strap bar and back upon the rear strap to which it is affixed therein securing the rear strap against slippage in length under load in its securement to the rear bar, which hole in the base bottom is formed as the rear strap bar is cut and bent out of the base bottom into a C-shaped bar opening rearward of the tie down.