Safety Chain Arrangement for Towed Vehicles

1. Field of the Invention

The invention relates generally to a safety arrangement for assuring that loss of control of a towable mixer will not occur in the event of failure of its hitch connection with the towing vehicle. More particularly, the invention relates to towable plaster, mortar or concrete mixers having a front post or pedestal located on the towing end of the mixer. The safety device of the present invention relates to the combination of a compartmented slotted front post of such a towable mixer, together with a safety chain having a hook, snap, or other fastening device on each end.

2. Description of the Prior Art

Use of safety chains is known for plaster, mortar, or concrete mixers and other trailers, and the like, having a hitch mechanism attached to a tow pole for towing by a towing vehicle. Such safety chains are attached to the tow pole and afford some degree of protection against failure of the hitch mechanism. However, when safety chains are attached to the tow pole, the danger exists that, in the event of failure of the hitch mechanism connecting the tow pole with the towing vehicle, the tow pole could be dislodged from the towed device, with nothing remaining to connect the towed device to the towing vehicle.

The present invention avoids hazards associated with prior methods of attaching safety chains to a towable mixer, specifically to plaster, mortar, or concrete mixers having a front post and tow pole, by linking the safety chain directly through the front post.

Accordingly, it is an object of the present invention to provide a safety device for linking a towing vehicle with a towable mixer having a front post by linking a safety chain directly through the front post.

Another object of the invention is to provide a safety chain easily installed by use of a hook, snap, or other fastening device on each end.

Still another object of the invention is to provide a safety device having a safety chain having adequate length and strength to meet standard motor carrier safety regulations, where excess length can be easily stored to keep the chain clean, to prevent entanglement of the safety chain with an operator's feet and to prevent the chain from dragging on the ground during over-the-road towing.

Yet another object of the invention is to provide an improved retention means of the safety chain in the front post, comprising a keyhole where the slot is angled forward and down at an angle coinciding with the angle the chain makes when attached to the towing vehicle.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

FIG. 1 is a perspective view of the safety chain installed on a towing vehicle on the left, and a towable mixer on the right.

FIG. 2 is a fragmental side elevational view of the towable mixer disconnected from a towing vehicle and showing the invention when not in use.

FIG. 3 is a sectional view taken substantially upon a plane passing along section line 3--3 on FIG. 2, showing the invention when not in use.

FIG. 4 is a fragmental perspective view showing the manner of attachment of the end of the chain when in use.

FIG. 5 is a top plan view of the chain.

In FIG. 1, towing vehicle 10 is attached through hitch 12, which can be a loop hitch, ball hitch, or other suitable type of hitch, to tow pole 14 through loop 15. Tow pole 14 telescopes through frame member or front post 16 from a retracted position as shown in FIG. 2 to provide a relatively short protruding portion to allow the operator of towable mixer 18 or others to walk around the device without tripping over the pole to an extended in use position for connection with a towing vehicle as shown in FIG. 1. Towable mixer 18, which can be a plaster, mortar, or concrete mixer, or any other trailer or towed device of the construction shown, has a main beam 20 reinforced by channel-shaped gusset 22, which is welded to both the channel-shaped front post 16 and main beam 20. Gusset 22 is oriented with respect to front post 16 to create a compartment 24 for storage of a safety chain 26 of integral contruction when chain 26 is not in use, or for storage of excess links of chain 26 when in use. The lower surface of compartment 24 is formed by base plate 28, which is welded to front post 16 and gusset 22. Provision for draining any water collected within compartment 24 is made by openings drilled in plate 28, or by purposeful failure to complete the weldment between base plate 28 and front post 16 or gusset 22. When safety chain 26 is looped through front post 16 in the manner illustrated in FIG. 1, failure of hitch 12, through breakage or slippage of hitch pin or bolt 30, through failure of loop 15, or through disconnection of tow pole 14 from front post 16, causes retention of towable mixer 18 by the connection of chain 26 through hole 32 of towable mixer 18 and through its connection with towing vehicle 10, shown in FIG. 1 at bumper aperture 34. In prior safety chain attachment techniques, involving connection with tow pole 14, successful operation in the event of failure of hitch 12 depends upon maintenance of the integrity of the tow pole 14, and its connection with front post 16 through bolt 36 and the connection of the chain to the pole.

FIG. 5 shows safety chain 26, including end links 38 and 40 having snaps 42 and 44. End links 38 and 40 are of sufficient size so that they will not pass through hole 32, which prevents the chain from being completely removed from the post or completely stored in compartment 24 when the end links are connected thereto. Hole 32 is provided with slot 46 which coacts with hole 32 to form a keyhole through each leg or wall of the post for retention of links of chain 26 during operation of the invention. Slot 46 is angled forward and downward from hole 32 at an angle approximatey 30 degrees from the horizontal, such angle coinciding with the angle which chain 26 makes when attached to the towing vehicle 10. Chain 26 is retained in slot 46 under its own weight, forming a path approximated by a catenary curve.

If the relation between towing vehicle 10 and towable mixer 18 is such that chain 26 is too long for the distance between attachment points at slot 46 and aperture 34, excess chain links can be stored in storage compartment 24 during towing operating by pushing links of chain 26 through hole 32, and its counterpart on the opposite wall of front post 16, and securing appropriate links of chain 26 in the slots 46. Safety chain 26 is constructed of adequate length and strength to meet standard safety regulations, such as U.S. Department of Transportation Motor Carrier Safety Regulations. Further, although the invention has been described with reference to plaster, mortar, or concrete mixers, the invention has broad applicability. Also, any type of hook, snap-hook or other fastener device may be removably attached to ends of the chain as long as they will not pass through hole 32.

To place the safety chain into operation from its stored position in FIG. 2, each of the end links 38 and 40 of chain 26 is removed by use of snaps 42 and 44. Remaining links of chain 26 are grasped and the links of the chain in the slots 46 are disengaged and desired lengths of chain are pulled out of the post. Ends of chain 26 are now passed through aperture 34, as shown in FIG. 1, and looped back to a convenient inside link of chain 26. One end of chain 26 is fed through a link, as shown in FIG. 4, and the end link 38 is then reattached. End link 40 is similarly attached to an interior length of chain 26 to secure both ends of chain 26. Any excess slack in the lengths of chain 26 between the post 16 and bumper aperture 34 is placed interiorly of the post and the desired link of the chain engaged in slot 46 which positively locks each length of chain to the post independently of the other so that if one length of chain 26 becomes disconnected or breaks, the other length of the chain remains effective.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.