Drum construction for winches used with cargo tie-down straps

An winch drum for a winch used to secure cargo straps which restrain cargo transported on a flatbed vehicle. The winch drum has two D-shaped sections arranged with the flat surfaces spaced apart and facing each other to form a slot for receiving the end of a cargo strap. The arcuate surfaces of the drum sections form a generally cylindrical surface on which the strap can be wound. The flat surfaces of each drum section are formed by inturned sides which are butted together edge to edge. Each drum section has notches at the ends of the flat surfaces. Reinforcing plates are secured in the winch drum by welding them to the drum sections adjacent to the notches. This construction exhibits strength because the reinforcing plates resist any tendency for the tubular drum to collapse.

FIELD OF THE INVENTION 
This invention relates generally to winches of the type used with cargo 
tie-down straps to secure cargo on flatbed vehicles. More particularly, 
the invention is directed to a winch having a structurally enhanced drum 
construction. 
BACKGROUND OF THE INVENTION 
It is common in the trucking industry for cargo that is transported on 
flatbed trucks to be held down by cargo straps drawn tightly over the 
cargo. These straps are secured at one end to one side of the cargo bed, 
are drawn over the cargo, and are held tightly by a winch mounted on the 
other side of the cargo bed. The winch typically has a ratchet and pawl 
mechanism which locks the winch drum in order to retain the cargo straps 
in a tight condition. 
One type of winch that has been used advantageously is disclosed in U.S. 
Pat. No. 5,490,749 to Arbues. However, the configuration of the slots 
through which one end of the cargo strap is threaded can cause problems. 
The slots in the Arbues winch drum are surrounded by edges having sharp 
corners that can cut or otherwise damage the cargo strap webbing. This 
slot configuration does not provide the winch with a strong construction, 
and the winch drum is thus susceptible to possible structural problems. If 
the drum is crushed in a collision, the slot edges can easily cut through 
the cargo strap. The cargo is then released, and the consequences of the 
collision can be greatly aggravated. 
It can also be somewhat difficult to feed the strap through the slots, as 
the strap end can catch on the edge opposite the slot into which it is 
initially inserted. The strap end is often doubled over before it is 
thread through the drum slot. The doubled over webbing naturally tends to 
spread apart, and this makes it even more susceptible to catching on the 
slot edges. 
Winch drums have also been constructed using two D-shaped sections welded 
together near the ends and with flat surfaces spaced apart and facing one 
another to provide opposite sides of the slot that receives the cargo 
strap. A variation of this construction involves bending the sides again 
to form flanges that are perpendicular to the flat surfaces on opposite 
sides of the slot. The primary problem with both of these constructions is 
that the winch drum can collapse and be crushed when subjected to heavy 
forces. There is no structure oriented perpendicular to the drum axis in 
order to provide effective resistance to crushing forces. 
SUMMARY OF THE INVENTION 
The present invention is directed to a winch drum having a special slot 
configuration which is reinforced at its opposite ends to increase the 
strength of the winch drum and its resistance to crushing forces, and to 
facilitate feeding of the strap through the slot. 
In accordance with the invention, the winch drum is constructed of two drum 
sections which are each formed in the general shape of the letter D. The 
arcuate portions of the drums cooperate to form a generally cylindrical 
surface on which cargo straps can be wound. The flat surfaces of the drums 
are spaced apart and face one another to form a slot which extends 
continuously through the diameter of the drum with the flat surfaces 
extending along the entirety of the slot. As a consequence, the flat 
surfaces provide assistance in guiding of the strap through the slot 
without difficulty and without catching on any edges or corners. 
Each drum section is preferably formed from a flat plate which is stamped 
in the desired shape and then rolled to form the arcuate surface in its 
center portion. The flat surface of each drum section is formed by turning 
the sides of the plate inwardly from the edges of the arcuate portion, 
with the opposite sides butting up against one another edge to edge. 
It is a particular feature of the invention that the winch drum is provided 
with two reinforcing plates which fit within the drum at the opposite ends 
of the slot. The plates occupy planes that are perpendicular to the drum 
axis and thus resist loads tending to crush the drum. The drum sections 
have notches at the opposite ends of the slot to facilitate welding of the 
reinforcing plates to the drum sections in a manner to assure strong 
connections.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to the drawings in more detail and initially to FIG. 1, 
numeral 10 designates the frame of a flatbed truck having a flat bed 12 
carrying cargo 14. The cargo 14 may take a variety of forms, and it is 
held down and restrained on the bed 12 by a plurality of flexible cargo 
straps 16. Each strap 16 has one end hooked or otherwise fixed in a secure 
manner to the side of the frame 10 opposite the side that is visible in 
FIG. 1. The straps are drawn over the top of the cargo 14, and each strap 
16 is received at its other end and tightened by a winch 20 which is 
constructed in accordance with the present invention. 
With reference now more particularly to FIG. 2, each of the winches 20 has 
a rigid frame 22 preferably constructed of a bent metal plate. The frame 
22 may take the shape of an inverted letter U having parallel opposite 
sides 22a and a horizontal bight portion 22b which connects the upper 
edges of the sides 22a. The bight portion 22b is connected with the frame 
10 of the vehicle in a suitable manner such as by bolting or welding it to 
the underside of the bed 12. Alternatively, the winch frame 22 can be 
fitted into a track (not shown) which is secured to the vehicle frame and 
which permits each winch to be adjusted in position forwardly and 
rearwardly along the length of the vehicle. 
Each winch 20 includes a cylindrical winch drum which is generally 
identified by numeral 24 and which extends between the sides 22a of the 
winch frame 22. The drum 24 is fitted through round openings in the frame 
sides 22a and is able to rotate about a horizontal axis parallel to the 
longitudinal axis of the vehicle and coincident with the longitudinal axis 
of the drum 24. 
In accordance with the present invention, the winch drum 24 has a special 
construction which includes a pair of identical drum sections 26. 
Preferably, each drum section 26 is formed from a flat metal plate which 
is stamped to provide it with the desired shape. The two drum sections 26 
cooperate to provide a slot 28 which extends through the winch drum 24 
along its diameter. 
As best shown in FIGS. 4 and 5, each drum section 26 presents in cross 
section the general shape of the letter D in the area of the slot 28. Each 
section 26 has an arcuate center portion 30 which forms the outer surface 
of the drum section. Opposite side portions 32 of the plate from which 
each section 26 is formed are turned inwardly from the edges of the 
arcuate section 30. The portions 32 are generally flat and terminate in 
edges that are butted against one another at 34. The drum sections 26 are 
secured in a manner that the flat surfaces provided by the portions 32 are 
spaced apart and generally parallel to one another to present the slot 28 
between them. By virtue of this construction, the slot 28 is bounded 
throughout its length and width by the flat surfaces which are formed on 
its opposite sides by the inturned portions 32 of the drum sections. The 
size of the slot 28 between the opposing portions 32 can vary but should 
be large enough to easily receive a cargo strap 16, preferably even if the 
cargo strap is doubled over. 
Each of the side portions 32 is preferably smoothly bent inwardly from the 
arcuate portion 30 such that curved intersections are provided between 
each portion 32 and the corresponding arcuate portion 30. This eliminates 
sharp corners in the area of the slot 28 that could possibly cut or 
otherwise damage or weaken the cargo strap 16 when it bears against the 
intersections between portions 30 and 32. 
The slot 28 does not occupy the entire length of the winch drum 24, and its 
length is slightly less than the distance between the opposite sides 22a 
of the winch frame. On opposite ends of the slot 28 at locations adjacent 
the frame sides 22a, the arcuate portions 26 are semi-cylindrical and 
terminate in edges which are adjacent to the edges of the opposing drum 
section, as indicated at 36 in FIG. 5. Thus, on opposite ends of the slot 
28, the drum sections 26 provide a nearly complete cylinder. In the area 
of the slot 28, the arcuate portions 30 of the opposing drum sections 26 
cooperate to provide a generally cylindrical surface that is interrupted 
only by the slot 28 and is able to receive the cargo strap 16 wound around 
it in a roll such as the roll 38 shown in FIG. 3. 
At each end of the slot 28, a pair of notches 42 (FIG. 4) are formed in 
each of the drum sections 26. The notches 42 extend in a circumferential 
direction on the drum 24 and are thus generally perpendicular to the 
longitudinal axis of the drum. The slots 42 are adjacent to the edges 36 
of the arcuate portions 30 of the drum sections and are also adjacent to 
the opposite ends of the inturned portions 32 of the drum sections. The 
notches 42 form transition areas between the ends of the inturned portions 
32 and the nearly cylindrical portions of the drum located adjacent to the 
frame sides 22a. 
A pair of reinforcing plates for the winch drum 24 may take the form of 
metal disks 44. Each disk 44 has a diameter substantially equal to the 
inside diameter of the drum 24. The disks 44 are inserted inside drum 24 
and butted against the edges at the opposite ends of the inturned side 
portions 32. This locates the disks adjacent to the notches 42, as best 
shown in FIG. 4. The disks 44 are planar members which occupy planes 
perpendicular to the longitudinal axis of the winch drum 24. The circular 
periphery of each disk 44 is in contact with the arcuate wall portions 30 
of the drum sections 26 along substantially its entire length. 
After the two drum sections 26 are assembled with their arcuate portions 30 
cooperating to form a cylindrical surface and their flat portions 32 
spaced apart and facing each other to form the slot 28, the disks 44 are 
secured in place by welds 46. The welds 46 are applied through and fill 
the notches 42 which are located adjacent to the edges of the disks 44. 
The welds 46 secure each disk 44 to both of the drum sections 26 and also 
secure the two drum sections together adjacent the edges 36 and the 
opposite ends of the slot 28. 
The notches 42 and welds 46 may be provided on only one side of the drum 
24. Alternatively and preferably, the notches 42 are provided in pairs in 
both edges of each drum section 26 so that each section has four notches 
and there are two sets of notches at each end of the slot 28 which are at 
diametrically opposed locations. The welds 46 are then four in number. The 
notches 42 on one drum section 26 are aligned with the notches on the 
other drum section to provide convenient access to the disks 44 for 
applying the welds 46 in a manner to assure a strong connection. 
As shown in FIG. 2, an enlarged collar is fitted around and secured to one 
end of the winch drum 24 at a location adjacent to the outside surface of 
one of the frame sides 22a. The collar 47 fits closely and fully around 
the arcuate portions 30 on the end of the drum 24 where the arcuate 
portions form a nearly complete cylinder. Collar 47 may be welded on its 
end to both of the arcuate portions 30, thus helping to secure the drum 
sections 26 together. The welds 46 assure that the drum sections 26 remain 
fixed while the collar is applied and secured in place. The collar 47 is 
larger in diameter than the drum 24 and is too large to fit through the 
opening in the frame side 22a through which the drum 24 extends. The 
collar 47 has diametrically opposed openings 48 (see FIG. 2) through which 
a cylindrical rod or the like (not shown) can be extended and used as a 
lever for turning of the winch drum 24. 
A ratchet wheel 50 is secured on the end of the winch drum 24 opposite the 
end which carries the collar 47. The ratchet wheel 50 is fitted closely 
and fully on the cylindrical end portion of the drum 24 at a location 
adjacent to the outside surface of one of the frame sides 22a where the 
arcuate portions 30 form a nearly complete cylinder. The ratchet wheel 50 
may be welded on its end to both of the drum sections 26, thus assisting 
in securing of the drum sections together. The collar 47 and ratchet wheel 
50 retain the winch drum 24 against axial movement relative to the frame 
22, although the drum is able to rotate as previously indicated. 
As described more fully in U.S. Pat. No. 5,490,749 to Arbues, which is 
incorporated by reference, the ratchet wheel 50 may have two sets of 
staggered ratchet teeth 52 which are located in offset planes. 
A pawl 54 cooperates with the ratchet wheel 50 in order to lock the winch 
drum 24 against rotation in a direction to unwind the cargo strap 16. The 
pawl is pivotally secured at one end to a pivot coupling 56 which is 
secured to the frame side 22a. The coupling 56 has an axis parallel to the 
axis of the winch drum and has an enlarged head in order to retain the 
pawl adjacent to the outer surface of the frame side 22a. As described 
more fully in the aforementioned Arbues patent, the pawl 54 may have two 
staggered sets of teeth that interlock with the teeth 52 of ratchet wheel 
50 when the pawl is in the locking position shown in FIG. 2. The 
interaction between the teeth of the wheel and pawl prevents the ratchet 
wheel 50 from turning in one direction but allow turning in the opposite 
direction, with the teeth slipping in and out of meshing engagement. The 
pawl 54 can be pivoted upwardly about the coupling 56 to a release 
position wherein its teeth are displaced from the ratchet wheel teeth, and 
the winch drum 24 is then released so that it can rotate in both 
directions. 
In use, the winch 20 acts to retain cargo strap 16 in a tight condition in 
order to restrain the cargo 14. After one end of the cargo strap is hooked 
to one side of the vehicle frame, the strap 16 is drawn over the cargo 14, 
and its opposite end 60 (see FIG. 3) is threaded through the slot 28. The 
winch drum 24 may be turned by hand in a counterclockwise direction as 
viewed in FIG. 3 in order to wind the strap 16 around the winch drum 24 to 
form a roll 38 on the drum. The slot 28 holds the strap end 60 in order to 
prevent the strap from slipping as it is wound around the winch drum. 
After the winch drum has been turned as far as possible by hand, a rod or 
other tool is extended through the collar openings 48 and used as a lever 
to turn the collar 47 in order to additionally rotate the winch drum 24 
until the strap 16 is tightened as fully as possible. Due to the influence 
of gravity, the pawl 54 is naturally engaged such that its teeth mesh with 
the ratchet wheel teeth. As the winch drum is tightened to tighten the 
cargo strap 16, the ratchet wheel teeth are able to slip relative to the 
pawl teeth. 
The manner in which the slot 28 is formed involves providing the inturned 
portions 32 on each drum section 26 such that each drum section in the 
area of the slot is in the form of a substantially semi-cylindrical tube. 
This structure exhibits considerably more strength than an arcuate plate 
that is devoid of inturned portions such as 32. The provision of the 
reinforcing plates (disks 44) increases the strength significantly. 
Because the disks occupy planes perpendicular to the drum axis, they 
exhibit great resistance to forces tending to collapse or crush the winch 
drum. Consequently, the construction of the winch drum 24 provides 
structural strength that is able to withstand the forces to which the 
winch drum is subjected in use. 
The inturned side portions 32 provide substantially flat guide surfaces 
that border the opposite sides of the slot 28 so that there are no edges 
or corners on which the end portion of the cargo strap may catch. The 
disks 44 provide boundaries at the opposite ends of the slot 28 that 
prevent the strap from accidentally entering the fully cylindrical 
opposite end portions of the drum and possibly catching on something. It 
is common for the end 60 of the cargo strap to be doubled over as depicted 
in FIG. 3, and the end portion of the strap has a tendency to spread apart 
when doubled over, thus enhancing the possibility of the strap becoming 
caught. 
Although the reinforcing plates for the winch drum have been shown and 
described as disks, other shapes are possible. For example, square plates 
can be substituted in place of the disks, as can a variety of other 
shapes. 
From the foregoing it will be seen that this invention is one well adapted 
to attain all ends and objects hereinabove set forth together with the 
other advantages which are obvious and which are inherent to the 
structure. 
It will be understood that certain features and subcombinations are of 
utility and may be employed without reference to other features and 
subcombinations. This is contemplated by and is within the scope of the 
claims. 
Since many possible embodiments may be made of the invention without 
departing from the scope thereof, it is to be understood that all matter 
herein set forth or shown in the accompanying drawings is to be 
interpreted as illustrative, and not in a limiting sense.