Universal cable winding drum

A universal cable winding drum for winding and unwinding a cable connected thereto. The drum has a hollow central hub for securement to a rod associated with a winding mechanism to impart rotation to the drum. A cylindrical cable supporting wall is connected to the hub and extends thereabout for supporting a plurality of windings of a cable thereon. The cable supporting wall has a plurality of cable guide channels formed therein in side-by-side relationship and are interspaced at overlapping end regions whereby to constitute right and left hand cable guide channels so that the cable can be wound thereon from either side of the drum. The end of the cable is secured through an end one of the channels on the cylindrical wall of the drum.

BACKGROUND OF INVENTION 
(a) Field of the Invention 
The present invention relates to a cable winding drum as utilized in a door 
raising and lowering mechanism and wherein the drum of the present 
invention is provided with universal cable guide channels whereby to 
accept a cable winding from either the right or left hand side so that the 
drum may be used on either side of the door. 
(b) Description of Prior Art 
In a door raising and lowering system there is usually provided two cable 
winding drums, one positioned on each top side of the door. A steel cable 
is secured at one end to the bottom of the door and at the upper end to 
the drum. When the door is lowered or raised the drum is rotated and the 
cable is unwound or wound about the drum. 
SUMMARY OF INVENTION 
It is a feature of the present invention to provide an improved cable 
winding drum and wherein the drum is provided with right and left hand 
cable guide channels to form a universal drum whereby a single drum may be 
used and installed on either the right or left side of the door. 
Another feature of the present invention is to provide a universal cable 
winding drum providing a faster installation of a door raising and 
lowering mechanism and eliminating errors in packaging and also providing 
for a reduction in manufacturing costs and a reduction in inventory costs. 
Another feature of the present invention is to provide a universal cable 
winding drum in which there is provided adjustable cable securement means. 
According to the above features, from a broad aspect, the present invention 
provides a universal cable winding drum for winding and unwinding a cable 
connected thereto. The drum has a hollow central hub for securement to a 
rod associated with winding means to impart rotation to the drum. A 
cylindrical cable supporting wall is connected to the hub and extends 
thereabout for supporting a plurality of windings of a cable thereon. The 
cable supporting wall has a plurality of cable guide channels formed 
therein in side-by-side relationship. The channels define valleys and side 
peaks with the valleys diminishing in depth from diametrically opposed 
points on respective opposed half-sections of the drum to an intermediate 
mid-area on diametrically opposed sides of the cable supporting wall where 
said peaks of the channels of one of said half-sections are interspaced 
and overlap in length with the peaks of the other half-section and taper 
within the drum table supporting wall. The channels thus constitute right 
and left hand cable guide channels. Means is provided to secure an end of 
the cable to the drum.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring now to the drawings, there is shown generally at 10 the universal 
cable winding drum of the present invention. The drum comprises a hollow 
central hub 11 which is adapted for securement to a support rod (not 
shown) which is usually associated with a coil spring thereabout to impart 
rotation to the drum. The drum has a cylindrical cable supporting wall 12 
connected to the hub by spokes 13 thus to form a drum with a hollow 
interior 14. 
The cylindrical cable supporting wall 12 extends concentrically about the 
hub 11 and is provided with a plurality of cable guide channels 15 whereby 
to support a plurality of windings of a cable 16 thereon. The cable guide 
channels 15 are formed in the supporting wall 12 in side-by-side 
relationship and define valleys and side peaks 17 and 18 respectively. The 
valleys diminish in depth from diametrically opposed points, herein 
defined by axis 19 in FIG. 1, on respective half-sections of the drum to 
an intermediate mid-area 20 on diametrically opposed sides of the cable 
supporting wall. 
As can be seen clearly in FIG. 2, the peaks 18 of the channels 15 in one of 
the half-sections of the drum are interspaced and overlap in length with 
the peaks of the channels in the other half-section and taper within the 
drum cable supporting wall surface. Thus, as is clearly seen in this 
Figure, the pulley can accept a winding of the cable 16 from either 
direction and thus the drum can be used as either a right hand drum or 
left hand drum. It can be seen that the peaks 18 of the cable guide 
channels 15 in each half-section of the drum are disposed substantially 
parallel to one another and slightly angulated toward their intermediate 
mid-area 20. Because the peaks in the mid-area 20 are substantially flush 
with the outer surface of the wall 12, the cable 16 wound thereon can 
cross over to the guide channels 15 from one half-section of the drum to 
the other. 
In order to prevent the cable 16 wound on the drum cable supporting wall 
from slipping off the wall, there is provided an end flange 21 formed 
integral with the supporting wall and disposed at each side thereof. In 
fact, the entire drum is formed as an integral part and is preferably, 
although not exclusively, made as a die cast of aluminum thus making the 
drum strong and light-weight. 
In order to secure the cable 16 to the drum, there is provided a cable 
entry hole 22 which is formed transverse in an end one of the cable guide 
channels 15. The entry end of the entry hole 22 has opposed curved tapers 
23 to define a flared end thus providing a smooth curved support surface 
for the cable at its entry point into the hole 22 whereby to prevent the 
cable from kinking and breaking in that region (see FIG. 1). The entry 
hole 22 is provided with an exit end 24 intermediate the hub 11 and the 
support wall 12 whereby a cable securing end will exit through the hollow 
interior 14 to permit access thereto such that a pulling tool, i.e. a pair 
of pliers, can be inserted to pull the wire taut through the cable entry 
hole 22. A threaded bore 25 is provided in intersecting relationship to 
the entry hole 22 and receives therein an arresting fastener (not shown) 
whereby the fastener can arrest the cable end in the entry hole 22 once it 
has been properly adjusted. 
As shown in FIG. 2, an access hole 26 may also be provided in the cable 
supporting wall 12 to provide access to a fastener secured to the hub 11 
to mount the pulley on its support rod (not shown). Further modifications 
to the drum are foreseeable and it is within the ambit of the present 
invention to cover these, provided they fall within the scope of the 
appended claims.