Car door opening tool and method

A car door opening tool for opening a car door of the type having a locking bar located within that functions to open the car door in response to the application of an unlatching force thereto. A shaft of sufficient length to access the locking bar through the car door's window slot from a position outside of the car door is provided with coupling device at its gripping end for both engaging the locking bar and for gripping it in response to a force-couple applied to the handle end of the shaft. By inserting the gripping end of the shaft through the window slot to engage the locking bar and then applying a force-couple to the handle end while simultaneously impressing the unlatching force to the shaft, the car door is caused to open.

BACKGROUND OF THE INVENTION 
This invention relates in general to car door opening tools, and more 
particularly to tools which are used to open a car door of the type having 
an otherwise generally inaccessible locking bar located within it which 
functions to open the door in response to the application of an unlocking 
force. 
DISCUSSION OF THE PRIOR ART 
It is well known that persons who have locked themselves out of their car 
in a remote or dangerous location, at a later hour, in inclement weather, 
or at a time when they are late for an engagement, experience the fears 
and frustations involved, and the need for a tool for opening the locked 
car door. 
A spare set of keys is often unavailable, a capable locksmith is often 
difficult to locate, and the car door opening tools employed by tow-truck 
operators and policemen are often ineffective. A person is often left with 
the option of breaking one of the car windows to gain access. 
Existing tools for opening a car door employ various configurations for use 
in opening various types of car doors. Some are of the "coat-hanger" type. 
They are made from a flexible wire bent into a form enabling the user to 
access the car door locking button from a position outside of the car door 
by inserting the tool through the weather stripping around the car door or 
car door window. 
Other tools are formed so that the user can insert the tool through a car 
door window slot into the interior of the car door to engage and pull the 
car door locking bar contained therein. 
Still other tools are designed to be inserted through some other opening in 
the car door such as the latch opening in order to fish for and engage the 
locking bar in an attempt to pull it sufficiently to unlock the door. 
Existing tools for opening car doors are often difficult to use because 
they require "fishing" for the locking bar. The operator must often have a 
good knowledge of the interior of the car door and the position of the 
locking bar, and he must often patiently move the unlocking tool about in 
the interior of the car door in a haphazard attempt to engage the locking 
bar. 
Existing car door opening tools often have no adequate means of engaging 
the locking bar so that longitudinal motion can be conveniently imparted 
thereto. After locating and engaging the locking bar, the tool can slide 
along the length of the locking bar without imparting sufficient motion 
thereto to unlock the car door. Such existing tools can grip the locking 
bar only at a point where the locking bar has a bend in it. 
Large forces must be impressed at one end of some existing tools to cause 
them to grip the locking bar so that sufficient longitudinal motion will 
be imparted to it to unlock the car door. Such tools are often difficult 
to grasp or pull to impart sufficient longitudinal motion to the locking 
bar. 
Additionally, existing tools for opening car door are often adapted for use 
with only the right hand or left hand door, a separate tool being required 
for each side of the car. 
Therefore, it is desirable to have a car door opening tool with which a 
person can quickly and easily locate and grip the locking bar in order to 
pull it sufficiently to open the car door. It is desirable to be able to 
grip the locking bar at a point on the locking bar that has no bend. It is 
further desirable to have a car door opening tool that can open both the 
left-hand and right-hand doors of a car. 
SUMMARY OF THE INVENTION 
In an exemplary embodiment, the invention provides a car door opening tool 
intended for use with a car door having a locking bar located within that 
functions to open the door in response to the application of an unlatching 
force. The tool employs a shaft which can be inserted along side the car 
door window into the interior of the car door to engage the locking bar. 
Coupling means connected to the end of the shaft act to grip the engaged 
locking bar when the shaft is axially twisted and to couple the unlatching 
force from the shaft to the locking bar, so that by simultaneously axially 
twisting the shaft while impressing the unlatching force to the shaft 
causes the car door to open. 
The car door opening tool may employ a string attached to it near the 
locking bar so that the unlatching force can be applied to the car door by 
gripping the locking bar with the tool and pulling on the string from a 
position outside of the car door. 
The invention therefore provides a new and improved tool which may be used 
to open therefore difficult to open locked doors. It can grip a locking 
bar at a straight section thereof as opposed to being able to grip the bar 
only where a bend exists. With a string attached to the tool, it can be 
used to couple an unlatching force to a difficult-to-access locking bar 
with the string bending around any corners or obstacles that may lie 
between the locking bar and an operator of the tool. Thus, the invention 
is a useful addition to the tools carried by policemen, tow-truck 
operators, and locksmiths, and a convenience to any person that may be 
called upon to assist in opening a car door. 
The objects, features and advantages of this invention will be readily 
understood when the detailed description thereof is read in conjunction 
with the accompanying drawing therein:

DETAILED DESCRIPTION OF THE INVENTION 
With reference to the drawing, the details of the car door opening tool 
constructed in accordance with the principles of this invention are shown. 
The tool is referred to generally by reference number 11, and by reference 
to FIG. 1 it can be seen to comprise basically a an elongate, 
substantially straight shaft 12 having a handle end 13 with a handle 17 
and a gripping end 14 with coupling means formed by an offset member 15 
and a coupling or locking bar engaging device 16. FIG. 1 illustrates the 
coupling device 16 engaging a locking bar 21. Also illustrated in phantom 
lines in FIG. 1 is an alternate embodiment 22. 
The car door opening tool illustrated is of single piece construction, 
preferably made from a length of wire-like material such as circular bar 
stock formed to the desired configuration. Other materials and methods of 
fabrication may be used as long as the tool is sufficiently strong to 
withstand the forces required to grip and move the locking bar, and 
sufficiently rigid not to deform during such use. As can be seen, a handle 
is formed at handle end 13 of the shaft 12 by a few simple bends in the 
wire. An alternate embodiment 22 may be formed at the handle end to serve 
both as a handle and as an alternately-dimensioned offset member with 
another coupling device formed therein. An approximately five inch long 
offset member has been found advantageous as an alternate. The handle 
serves as a means to grasp the shaft with one's hand and to facilitate 
axially twisting the shaft as well as facilitating the application of an 
axially-directed engaging force and an unlatching force to the shaft. The 
handle also serves to prevent the shaft from sliding entirely within the 
car door interior, as well as providing a convenient means of holding the 
tool as it is being positioned through the car door window slot or 
otherwise. 
Shaft 12 is made form steel wire-like material such as circular bar stock 
of approximately one-eighth stock diameter. It is particularly 
advantageous in the practice of the invention to use 17-4PH heat treated 
stainless steel, which has been found withstands the bending forces 
involved without deforming, although other sizes and materials may suffice 
to withstand the forces involved. Generally available spring steels may be 
used to withstand the bending forces involved. The wire is of generally 
circular cross section, although other cross sections may be used as long 
as they do not substantially impair the ability to twist the shaft after 
it has been inserted through the car door window slot, it being desired to 
twist the shaft so that the offset member can be positioned parallel to 
the car door window in order to insert it through the car doow window slot 
and then positioned to engage the car door locking bar 21 by twisting the 
shaft approximately one-quarter turn. The distance between handle end 13 
and gripping end 14 is approximately fifteen inches, although the length 
of the shaft may be varied so long as it is sufficient to allow engaging 
the locking bar with the coupling device with the shaft extending through 
the car door window slot to a position outside of the car door. The shaft 
is straight between its handle and gripping ends. 
Offset member 15 is formed by bending the wire-like material used to form 
shaft 12 so that a substantially right angle is formed. The length of 
offset member 15 is approximately two inches, although other lengths may 
be employed so long as the offset member is not too long to allow 
inserting the gripping end 14 and coupling device 16 through the car door 
window slot 25, nor tool ong to permit positioning offset member 15 and 
coupling device 16 in the car door interior 31 between the interior 
surface of inside door panel 32 and the interior surface of outside door 
panel 33. 
Coupling device 16 is formed from the length of wirelike material into a 
hook-type configuration, although other materials and methods of 
fabrication can be employed without avoiding the inventive concept therein 
embodied. The hook-type configuration has a hook opening which is 
dimensioned to enable the hook-type configuratin to fit partially around 
the locking bar 21 so that it can hook onto and engage the locking bar 
with the hook opening facing generally away from handle 17 in a direction 
substantially parallel to the longitudinal axis of shaft 12. As can be 
seen with reference to FIG. 4, the hooktype configuration of coupling 
device 16 may open in any other direction so long as the axially-directed 
engaging force illustrated by arrow 26 is applied in the same direction 
and the moment illustrated by arrow 27 is applied so as to cause the 
hook-type configuration to grip the locking bar. 
Referring again to FIG. 1, it is seen that the hook-type configuration of 
coupling device 16 has a hook opening illustrated by dimension 37 which is 
approximately one-fourth inch across, although other size openings can be 
employed as long as they easily fit around locking bar 21 sufficiently to 
engage and grip it. It is also seen that the mouth of the hook opening is 
approximately three-sixteenths inch across as illustrated by dimension 38 
to allow the coupling device to be snapped onto locking bar 21 and 
retained there while the car door is opened, although the car door opening 
tool has been found to function effectively with the mouth of the hook 
opening equal to or greater than the hook opening itself. 
With reference to FIG. 1, it can be seen that the hook-type configuration 
of coupling device 16 is formed so that the hook opening cross sectional 
area generally conforms to the cross sectional area of a circular locking 
bar, although it may be otherwise formed as long as engagement of the 
locking bar is not significantly inhibited and the force-couple applied to 
the shaft causes coupling device 16 to grip locking bar 21 sufficiently to 
couple the unlatching force, illustrated in FIG. 4 by arrow 28, from the 
shaft 12 to locking bar 21 to move the locking bar and open the car door. 
With reference to FIG. 1 it may be readily understood that the coupling 
device may grip the locking bar by making contact with the locking bar, in 
response to axially-twisting the shaft, at two locations on the locking 
bar that are positioned generally diametrically opposite one another about 
the circumference of the bar. By axially-twisting the shaft sufficiently, 
a force-couple is generated at those locations of contact with sufficient 
resulting frictional forces to couple the unlatching force from the shaft 
to the locking bar. 
To further facilitate sufficiently gripping locking bar 21, coupling device 
16 may be provided with a friction enhancing coating 36 by commonly 
employed means such as dipping it in plastic or rubber. A suitable coating 
has been found to be H.C.F. Hard Coat Finish manufactured by P.D.I., Inc. 
of St. Paul, Minn., and the rubber or plastic coatings commonly applied to 
the handles of hand tools such as pliers may be used. 
FIG. 2 illustrates the car door opening tool 11 in position to open a car 
door 23 having a window 24 and an associated car door window slot 25 which 
defines an access way to the locking bar from a position outside of the 
car door thorugh which the car door unlocking tool can be inserted. The 
car door opening tool extends from a position outside of the car door 
through the car door window slot 25 to engage the locking bar 21. As 
further illustrated in FIG. 2, a car door opening tool may be used to open 
a car door by first engaging the locking bar, and then applying an 
axially-directed engaging force to the handle 17 as illustrated by arrows 
26. A twisting moment may then be applied to the handle as illustrated by 
arrow 27, while simultaneously applying a force to the handle in a 
direction 28A substantially parallel to the unlatching direction 28 of the 
locking bar 21 door opening tool in the manner illustrated in FIG. 2 will 
cause the unlatching force to be coupled by means of coupling device 16 to 
the locking bar 21, causing the locking bar to move and the car door to 
open. 
Positioning of the car door opening tool is further illustrated in FIG. 3 
wherein the shaft 12 is shown inserted through the car door window slot 25 
to a position where the coupling device 16 engages locking bar 21. As can 
be readily understood with reference to FIG. 3, offset member 15 offsets 
coupling device 16 from shaft 12 in order to facilitate engagement of 
locking bar 21. Offset member 15 also acts as a moment arm which 
facilitates gripping locking bar 21 with coupling device 16. Offset member 
15 may be dimensioned to fit easily inside car door interior 31 defined by 
the interior surface of the inside door panel 32 and the interior surface 
of the outside door panel 33. 
As illustrated in FIG. 4, the car door opening tool may be fitted with a 
string-like member 34, one end of which may be attached to coupling device 
16 or to offset member 15, with the other end extending through car door 
window slot 25 to a position outside of the car door and pulled upon as 
depicted in FIG. 4 by arrow 36 is such as to impart the unlatching force 
28 to the unlocking bar 21 to cause it to move and open the car door. The 
string-like member maybe a flexible wire, cord, string, or the like 
capable of bending around corners and obstacles which may lie between the 
locking bar and the position of the human hand 35. The string-like member 
employs a material of sufficient strength to withstand the required string 
force 36, and it also serves to reduce the strength requirements of the 
wire-like material used for the tool since less force is required to be 
exerted at the handle end. 
Reference to FIG. 4 illustrates the forces involved which function to grip 
the locking bar 21 sufficiently to couple the unlatching force illustrated 
by arrow 28 thereto. Axially twisting the shaft at the handle 17 results 
in the moment illustrated in FIG. 4 by arrow 27. The moment results in 
forces which may be visualized as a force-couple acting at two locations 
of contact between coupling device 16 and locking bar 21 on generally 
diametrically opposite sides of the locking bar. The force-couple acts to 
force the coupling device 16 against locking bar 21 at the two points of 
contact, with the resulting frictional forces acting to grip the locking 
bar sufficiently so that the unlatching force illustrated by arrow 28 can 
be coupled thereto. 
Frictional forces between coupling device 16 and locking bar 21 may be 
enhanced by the use of a friction enhancing coating on coupling device 16, 
the friction enhancing coating being most readily perceived in the 
drawings by reference to coupling device 16 in FIG. 1 wherein friction 
enhancing coating 36 is best depicted. 
Although the foregoing specification has described the use of the invention 
as involving the application of the unlatching force 27 by either pulling 
on handle 17 or string-like member 34, other means may be employed to 
impress the unlatching force on the shaft or offset member, such as by 
tapping the shaft with a hammer. 
The foregoing is a complete description of an exemplary embodiment of a car 
door opening tool which is constructed in accordance with the principles 
of this invention. It is likely that changes and modifications will occur 
to those skilled in this art which are within the inventive concepts 
disclosed and claimed herein.