U.S. patent number 3,848,293 [Application Number 05/342,539] was granted by the patent office on 1974-11-19 for dual action conical door hinge system.
This patent grant is currently assigned to Atwood Vacuum Machine Co.. Invention is credited to Joseph H. Marchione, John J. Skubal.
United States Patent |
3,848,293 |
Marchione , et al. |
November 19, 1974 |
DUAL ACTION CONICAL DOOR HINGE SYSTEM
Abstract
A locking pawl cooperates with a projection on the door bracket
to confine it during door opening movement, until the door reaches
an intermediate open position, whereupon the pawl is unlocked,
allowing the projection to move relative to the pawl through a
predetermined arc, the extent of throwout of the hinging axis for
the upper hinge being thereby accurately predetermined with both
designs of the upper hinge, with a view to allowing adequate head
room relative to the upper edge and rear corner of the glass on the
door for convenient and safe entry and exit relative to either the
front or rear door, the problem being usually more acute in the
case of the rear door.
Inventors: |
Marchione; Joseph H. (Rockford,
IL), Skubal; John J. (Rockford, IL) |
Assignee: |
Atwood Vacuum Machine Co.
(Rockford, IL)
|
Family
ID: |
23342267 |
Appl.
No.: |
05/342,539 |
Filed: |
March 19, 1973 |
Current U.S.
Class: |
16/297; 16/308;
16/354 |
Current CPC
Class: |
E05D
7/06 (20130101); E05D 3/10 (20130101); E05D
5/062 (20130101); Y10T 16/5385 (20150115); Y10T
16/5389 (20150115); E05Y 2800/26 (20130101); E05Y
2900/132 (20130101); Y10T 16/541 (20150115) |
Current International
Class: |
E05D
3/00 (20060101); E05D 3/10 (20060101); E05d
003/06 () |
Field of
Search: |
;16/163,164,139
;49/146 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gilliam; Paul R.
Assistant Examiner: Troutman; Doris L.
Attorney, Agent or Firm: Wolfe, Hubbard, Leydig, Voit &
Osann, Ltd.
Claims
We claim:
1. In a door hinging construction for pivotal mounting of a door on
a vehicle body, a pair of vertically spaced hinges in coaxial
relationship, the upper one of said hinges comprising a first fixed
member mounted on the vehicle body and a second movable member
mounted on the door, each of said members having thereon a
substantially horizontal segmental planetary gear portion, the
teeth of which are in rolling meshing engagement, upright pintles
on said members at the centers of the arcs of the respective
segmental planetary gears, these pintles being inclined relative to
one another on axes converging downwardly toward the lower hinge,
and links pivoted to the opposite ends of said pintles serving to
keep the segmental planetary gear teeth in mesh, the lower one of
said hinges comprising a first fixed member mounted on a vehicle
body, and a small movable member mounted on the door, these two
members having a universal joint connection pivotally connecting
the members for universal pivotal movement about the point of
convergance of the aforesaid axes, and door throwout control means
on the upper one of said hinges whicn in part-way opening of the
door prevents throwout of the door relative to said hinge but which
in further opening of the door allows a predetermined extent of the
door throwout relative to said hinge, said door throwout control
means in the closing of the door reversing its functioning.
2. In a door hinging construction for pivotal mounting of a door on
a vehicle body, a pair of vertically spaced hinges in coaxial
relationship, the upper one of said hinges comprising a first fixed
member mounted on the vehicle body and a second movable member
mounted on the door, each of said members having thereon a
substantially horizontal segmental planetary gear portion, the
teeth of which are in rolling meshing engagement, upright pintles
on said members at the centers of the arcs of the respective
segmental planetary gears, these pintles being inclined relative to
one another on axes coverging downwardly toward the lower hinge,
and links pivoted to the opposite ends of said pintles serving to
keep the segmental planetary gear teeth in mesh, the lower one of
said hinges comprising a first fixed member mounted on the vehicle
body, and a second movable mounted on the door, these two members
having a universal joint connection pivotally connecting the
members for universal pivotal movement about the point of
convergance of the aforesaid axes, and door hold-open mean on the
lower hinge comprising a torsion bar mounted in prestressed
condition on one of the two members of said lower hinge and having
a resilient deflectable bar portion which in the opening of the
door engages and is deflected by a striker detent carried on the
other of said hinge members as the deflectable bar portion moves
past the same, the striker detent and deflectable bar portion
remaining in a predetermined operative relation to one another
regardless of inclination of the door relative to the universal
joint in the lower hinge.
3. A door hinging construction as set forth in claim 1, and further
comprising door hold-open means on the lower hinge comprising a
torsion bar mounted in prestressed condition on one of the two
members of said lower hinge and having a resilient deflectable bar
portion which in the opening of the door engages and is deflected
by a striked detent carried on the other of said hinge members as
the deflectable bar portion moves past the same, the striker detent
and deflectable bar portion remaining in a predetermined operative
relationship to one another regardless of inclination of the door
relative to the universal joint in the lower hinge.
4. A door hinging construction as set forth in claim 1, wherein the
door throwout control means comprises a bracket on the hinged edge
of the door extending toward the upper hinge and pivotally
connected with one end of one of said links and having a projection
in spaced relation to said pivot spaced from an intermediate
portion of the aforesaid link, the door throwout control means
including a pawl, which in the first portion of opening movement of
the door retains said projection so as to allow only a certain
amount of throwout of the door for a first stage of thrwout up to
an intermediate open position of the door when the pawl previously
locked in the projection retaining position is automatically
released to allow pivotal movement of the bracket relative to the
end of the link to allow further throwout of the door up to the
fully opened position of the door.
5. A door hinging construction as set forth in claim 1 wherein the
door has a bracket on its hinged edge projecting toward the upper
hinge and pivotally connected with one end of one of said links and
the throwout control means comprises a pawl pivoted on one of the
substantially horizontal segmental planetary gears and having a
tooth which in the closed position of the door engages behind a
projection on the link, the pawl having an arm extending in the
other direction from the pivot in spaced relation to one end of the
segmental gear so that a projection on the bracket is held between
the arm and the segmental gear in a predetermined spaced relation
to the pivot between the arm and segmental gear between closed
position of the door and an intermediate open position after which
in further opening of the door, the tooth on the pawl unlocks from
the projection on the link allowing the projection on the bracket
to move further away from the pivot, the arm on said pawl having
first depression in the inner edge thereof wherein to confine the
projection on the bracket in the first stage of door opening
movement and a second depression in the inner edge thereof farther
removed from the pivot wherein to confine the projection on the
bracket in the later stage of door opening movement.
6. A door hinging construction as set forth in claim 1 wherein the
door has a bracket on its hinged edge projecting toward the upper
hinge and pivotally connected with one end of one of said links and
the throwout control means comprises a pawl pivoted on one of the
segmental gears and having a tooth whicn in the first portion of
door opening movement is engaged behind a projection on the link
holding a generally U-shaped portion of the pawl in straddling
relation to a projection on the bracket retaining it in one end of
an arcuate slot provided in said bracket, said releasing said
projection to move to the other end of the arcuate slot when the
tooth on the pawl becomes disengaged relative to the projection on
the link at an intermediate open position of the door to permit the
second stage of throwout of the door, the projection on the second
movable member returning to the first mentioned end of the arcuate
slot at the intermediate open position of the door in closing,
whereupon the tooth on the pawl reengages the projection on the
link to confine the projection in its first position in the final
closing movement of the door.
7. A door hinging construction as set forth in claim 5 wherein the
fixed member on the vehicle body has a stop projection thereon
spaced from the planetary gear teeth on said member, said stop
projection being engaged by a projection on the segmental gear
spaced from the gear teeth thereon, whereby to limit the rolling
meshing engagement when the door reaches a part-way open position,
all further relative movement of the rest of the parts occurring in
the further door opening movement to the fully open position of the
door as the second movable member swings relative to the pivot at
one end of said links.
8. A door hinging construction as set forth in claim 6 wherein the
fixed member on the vehicle body has a stop projection thereon
spaced from the planetary gear teeth on said member, said stop
projection being engaged by a projection on the segmental gear
spaced from the gear teeth thereon, whereby to limit the rolling
meshing engagement when the door reaches a part-way open position,
all further relative movement of the rest of the parts occurring in
the further door opening movement to the fully open position of the
door as the second movable member swings relative to the pivot at
one end of said links.
9. A door hinging construction as set forth in claim 1, wherein the
door in swinging open has a predetermined rise to mid-open
position, the construction including tension spring means in the
upper hinge which is stretched in the closing of the door from
approximately mid-open position on closed position to offset the
gravity effect and thereby avoid slamming of the door.
10. A door hinging construction as set forth in claim 2 including
tension spring means in the upper hinge which is stretched in the
closing of the door from approximately mid-open position to closed
position to counterbalance the assist action of the torsion bar and
thereby avoid slamming of the door.
11. A door hinging construction as set forth in claim 1, wherein
the door in swinging open has a predetermined rise to mid-open
position, the construction including tension spring means in one of
the hinges which is stretched in the closing of the door from
approximately mid-open position to closed position to offset the
gravity effect and thereby avoid slamming of the door.
12. A door hinging construction as set forth in claim 2 including
tension spring means in one of the hinges which is stretched in the
closing of the door from approximately mid-open position to closed
position to counterbalance the assist action of the torsion bar and
thereby avoid slamming of the door.
Description
This invention relates to a new and improved dual action conical
door hinging system and is more particularly concerned with
improvements on the single action conical door hinging system
disclosed in Slattery U.S. Pat. No. 3,594,853, the hinging herein
disclosed having been designed with the latest streamlined designs
of cars in mind and giving the increased head room required for a
person getting safely into or out of a car, by virtue of the dual
action of the geared link hinge at the upper location, the ample
head room avoiding any likelihood of a person bumping his head on
the upper edge portion of a glass on the door and possibly
sustaining cuts or bruises.
The need for relieving the cramped condition has become acute,
especially on rear doors with the recent style changes, that make
the radius of curvature of the glass on the door smaller and
smaller, thereby increasing the so-called "tumble home" to the
point where the glass on a rear door has its rear upper corner
sufficiently inboard relative to the hinging axis so that it not
only restricts entry and exit but gives rise to a serious danger of
injury by a person striking his head on the corner or upper edge of
the glass. The two designs of what we prefer to call "dual action
conical planetary hinging" avoid these difficulties by hinging the
door so that the upper portion thereof, instead of pivoting about a
conventional upright axis, is given ample outward movement away
from the body with both designs so that there is always adequate
head room for easier and safer entrance and exit.
We are aware that others have also worked on a solution for this
problem but, so far as we are aware, their constructions have not
been adopted to date for one reason or another, doubtlessly due to
the impracticability of their hinge constructions or their
prohibitive cost due to their complicated and expensive
constructions, or due to their failure to comply with the latest
safety requirements and limitations, all of which objections are
avoided in the constructions of our invention. "Dual action" is
incorporated in both designs herein diclosed, the hinging axis of
the door by virtue of the special construction of the upper hinge
being swung outwardly appreciably in the initial opening movement,
and in further opening movement being swung outwardly much futher,
assuring ample head room for anyone leaving or entering the car,
and, while the conical hinging action necessitates a universal ball
and socket construction in the lower hinge, the lower hinge in
accordance with the present invention is preferably of the novel
construction herein disclosed in which a torsion bar is included,
which in the opening movement is loaded so as to give the desired
degree of better control on the door' s swinging movement so that
it will not be so apt to bang into some object nearby, but be
cushioned in the event of such contact and also have sufficient
spring action stored therein to give appreciable assist action in
the closing of the door.
The upper hinge in both forms can be described as of the dual
action geared planetary link type. In the simpler one of the two
designs a substantially horizontal link of arcuate form is
pivotally connected at opposite ends to a body bracket and a door
bracket, respectively, and a plurality of arcuately arranged gear
teeth on the body bracket, having the pivotal connection as the
center of the arc, have meshing engagement with other arcuately
arranged gear teeth on the outer periphery of a gear segment
pivoted on the door bracket pivot, this gear segment having a
lateral projection near its outer end carrying a pivot for a
locking pawl, which, in the closed position of the door, engages
behind a projection on the link holding the keeper in closed
position, maintaining a hold on a cylindrical projection on the
door bracket but maintaining such hold on the projection only in
the initial opening movement of the door, so that the hinged edge
of the door cannot swing outwardly until after the projection on
the keeper swings clear of the projection on the link, when the
keeper allows the projection on the bracket to ride out of its
first position to the second position in the outer end of the
keeper, thereby limiting the outward swing of the door. A stop
projection on the body bracket serves as a limiting stop that is
engaged by the periphery of the segmental gear in a mid-position of
opening of the door, after which the final outward movement of the
hinged edge is made possible only by the riding of the cylindrical
projection on the door bracket lengthwise of the keeper from the
inner recess therein to the outer one.
The other top hinge is also of the dual action geared planetary
type and comprises a link of generally arcuate form pivoted at its
opposite ends on a body bracket and a door bracket, and there
again, there are actuately arranged gear teeth on the body bracket
meshing with arcuately arranged gear teeth on the periphery of a
segmental gear pivoted at its one end on the door bracket pivot in
a manner analogous to what is contained in the first hinge just
described. However, in this second hinge there is a locking pawl
pivoted on the outer end of the gear segment and having on its one
side edge a recess receiving a cylindrical projection mounted on
the door bracket that is movable in an arc with the door pintle as
a center, this projection moving an arcuate slot in the segmental
gear concentric with the door pintle, the position of the
projection in the slot determining the position of the locking pawl
so that with the door in the closed position the locking pawl has a
lug in locking engagement with a lug on the link. However, in the
initial door opening movement, the locking pawl has its lug move
clear of the lug on the link so as to free the projection on the
segmental gear to permit further door opening movement to the
extent permitted by the arcuate slot in the segmental gear, the
locking pawl being free at this point to swing about its pivot on
the segmental gear. In the initial closing movement of the door the
pawl is swung around into a position where its lug will engage
behind the lug on the link in the final door closing movement, and,
here again, there is a stop on the body bracket, which, in the
initial door closing movement, comes into engagement with a portion
of the periphery of the segmental gear to hold the link in a
position for swinging of the door about its inner end in the final
door closing movement.
The invention is illustrated in the accompanying drawings, in
which:
FIG. 1 is a vertical section through the body of an automobile
showing a ball and socket type lower hinge and indicating the
converging door hinging axis lines on which are located the
converging pintles on the upper hinge, one on the body bracket and
the other on the door bracket with the geared planetary hinge of
FIGS. 2 to 4 serving as the upper hinge;
FIGS. 2, 3, and 4 are top views of the upper hinge taken on line
2--2 of FIG. 1, showing the door closed in FIG. 2, and in an
intermediate open position in FIG. 3, and in fully opened position
in FIG. 4;
FIG. 5 is a view similar to FIG. 1, but showing a modified form of
ball and socket hinge at the lower location, incorporating a
torsion bar, as seen in FIGS. 5 and 6, and the geared planetary
hinge of FIGS. 7 to 9 in the upper location;
FIG. 6 is a top view of the lower hinge, taken on line 6--6 of FIG.
5, and
FIGS. 7, 8, and 9 are top views of the upper hinge taken on the
line 7--7 of FIG. 5, showing in FIG. 7 the closed position of the
door, in FIG. 8 an intermediate open position, and in FIG. 9 the
fully opened position of the door.
Similar reference numerals are used to designate corresponding
parts throughout these views in the following specification.
Referring to the drawings and more particularly to FIGS. 1 to 4,
illustrating what we have termed "conical hinging," the reference
numerals 11 and 12 designate the upper and lower hinges,
respectively, applied to a door 13 on a body 14, with a view to
having the fixed door's hinging axis a-b define the center line of
a cone described by the swinging hinging axis c-d, as indicated at
15 in FIG. 1, so that the upper portion of the door in opening
swings away from the body 14 to the extent clearly indicated in
FIG. 1, thereby causing the upper rear corner of the window to be
swung away from the body sufficiently to give ample entrance and
exit space and accordingly much reduced likelihood of anyone upon
entering or leaving the car striking their hand on the upper rear
corner or upper edge of the window and sustaining a cut or bruise.
The lower edge of the door with this novel hinging is kept at a
nearly uniform level throughout the door's movement, even though,
as previously indicated, the main objective has been to insure more
adequate head from for easier and safer entrance and exit.
Turning now to FIGS. 2 to 4, which illustrate the upper hinge 11
which, as previously indicated, is best described as a dual action
geared planetary link hinge, the body bracket 16 includes a
segmental gear 17 concentric with the pintle 18 that is inwardly
inclined to the small extent seen in FIG. 1, the gear 17 meshing
with arcuately arranged gear teeth 19 provided on the segmental
gear 20 pivoted at its inner end on the pintle 21 on door bracket
22. The pintle 21, as seen in FIG. 1, is outwardly inclined on axis
c-d. The axes a-b and c-d passing through the centers of the
pintles 18 and 21, respectively, converge to the center of the
ballhead 23 of the lower hinge 12. An arcuate substantially
horizontal link 24 is pivotally connected at its opposite ends to
the pintles 18 and 21. The gear segment 20 has a lateral projection
25 near its outer end carrying a pivot 26 for a locking pawl 27,
which, in the closed position of the door shown in FIG. 2 has its
radial lug 28 engaging behind a lug 29 on the link 24, while a
cylindrical projection 30 on the bracket 22 is held between the
edge of the gear segment 20 and an arcuate recess 31 provided on
the inner edge of the pawl 27, holding the door 13 closed. However,
when the door is opened partway to the intermediate position shown
in FIG. 3, the lug 28 moves clear of the lug 29 and the cylindrical
projection 30 is no longer locked between the pawl 27 and the edge
of the segmental gear 20, so at that point the projection 30 is
free to ride from the arcuate recess 31 at the inner end of the
pawl 27 into the other arcuate recess 32 provided in the outer end
of the pawl 27, and it is in this shifting of parts in the upper
hinge 11 that the stop projection 33 on the outer end of the body
bracket 16 comes into engagement with the corner portion 34 on the
outer end of the gear segment 20, allowing the door bracket 22 to
swing freely about the pintle 21, so that the cylindrical
projection 30, previously mentioned, can ride from the inner
arcuate recess 31 out into the outer arcuate recess 32 of the pawl
27, so the hinge 11 permits the door 13 to swing farther out and
accordingly gives the desired added clearance between the glass on
the door and the body to provide the additional head clearance for
safer and easier entrance and exit. Obviously, in the closing of
the door the series of movements just described are reversed, the
projection 30 moving inwardly along the pawl 27 from the outer
arcuate recess 32 into the inner arcuate recess 31, as seen in FIG.
3, and then in the further closing movement of the door the lug 28
on the pawl 27 rides behind the lug 29 on the link 24, and finally
the hinge parts are all locked up firmly as they appear in FIG. 2
when the door is closed.
The lower hinge 12, which, as previously indicated, is of the ball
and socket type, has the ballhead 23 received in a socket 35, a
retaining plate 36 being secured to the socket to hold the ballhead
therein while allowing operating clearance for the small amount of
inclination of the door with respect to the body in the opening and
closing of the door, the yoke 37 serving to limit the door opening
movement positively.
The operation should be clear from the foregoing description. Upper
and lower links 24 and 38 positively maintain the spaced and
inclined relationship of the pintiles 18 and 21, and, in the
opening of the door, due to the rolling of the gear teeth 19 on the
gear teeth 17, the axis c-d on which pintle 21 on the door 13 lies,
moves through an angle of approximately 40.degree. in the
approximately 80.degree. opening movement of the door, with the
result that the upper portion of the door 13 is swung outwardly
away from the body 14, causing the window on the door to have its
upper edge swung out much farther to provide the needed head room
for convenience and safety in entering and leaving the car. The
universal joint action of the lowering hinge 12 permits this
angular displacement of the door in rotation to the body, while
still supporting the door for steady hinging in the opening and
closing movements. The lower edge of the door remains nearly
parallel to the ground or sidewalk throughout the 80.degree.
movements of the door, being only slightly higher at mid-open
position due to inclination of the axis c-d.
Referring next to the other construction, shown in FIGS. 5 to 9,
the lower hinge 12' is of a modified ball and socket type so as to
include a torsion bar 39 similar to that disclosed in Marchione
U.S. Pat. No. 3,371,374 to give a hold-open action by virtue of the
fact that the door 13', on which the plate 40 is mounted, turns
relative to the ball 23' mounted on plates 41 carried on the body
14'. The torsion bar 39 has one of its radially extending arms 42
fixed, as at 43 at its outer upturned end to the plate 40, while
the other radius arm 44 at the other end of the torsion bar has its
downwardly extending end 45 movable in an arc about the vertical
mid-portion 46 of the bar 39 for loading from a preload position at
the outset or commencement of door opening movement, by deflection
upon contact with strikers 47 and 48 mounted on and projecting from
one of the plates 41 carried on the body, to increase the spring
tension in the torsion bar above preload spring tension in the door
opening movement of the plates 40 and 41 relative to one another
for a hold-open action, as disclosed in the aforementioned
Marchione patent. The strikers 47 and 48 are in the form of
scalloped rollers which give a detent action as the end portion 45
of the torsion bar rides onto and past one or the other of the
rollers, thus holding the door open and giving better assurance
that in the event of wind pressure or by someone accidently
brushing against the open door when it is not intended to close it,
the detent acton prevents accidental closing of the door. The slot
indicated at 49 in FIG. 6 in the upper flange of plate 40 allows
for the arcuate swinging movement of the end portion 45 of arm 44
torsion bar 39.
Referring now to FIGS. 7, 8, and 9, which illustrate the upper
hinge 11', there is a general similarity in this geared link-type
hinge to that shown in FIGS. 2, 3, and 4, but with this more
sophisticated design of the upper hinge, the throwout of the upper
portion of the door is increased appeciably and yet the relatively
movable parts of the hinge are just as securely interlocked to
insure smooth swinging movement of the door first from closed
position shown in FIG. 7 to the intermediate position shown in FIG.
8, and finally to the fully open position shown in FIG. 9. The body
bracket 16', similarly as in the other construction, includes a
segmental gear 17' concentric with the pintle 18' that is inclined
inwardly to the small extent seen in FIG. 5, the gear 17' meshing
with arcuately arranged gear teeth 19' concentric with the pintle
21' provided on the segmental gear 20' that is pivoted at its inner
end on the pintle 21' on door bracket 22'. The pintle 21', as seen
in FIG. 5, is outwardly inclined. The axes a-b and c- d passing
through the centers of the pintles 18' and 21', respectively,
converge to the center of the ball 23' in the lower hinge 12'. An
arcuate, substantially horizontal, link 24' is pivotally connected
at its opposite ends to the pintles 18' and 21', and there is a
corresponding link 38'on the bottom of the hinge 11' connecting the
lower ends of the pintles 18' and 21' to maintain their fixed
spaced and inclined relationship, similarly as in the upper hinge
11, first described. So far, the similarity in hinges 11 and 11' is
evident. However, in this second hinge 1' there is a locking pawl
27' that is quite different from the locking pawl 27 of hinge 11,
the pawl 27' being pivoted at 26' on the outer end of the gear
segment 19' and having on its inner side a single arcuate recess
31' receiving a cylindrical projection 30' mounted on the door
bracket 22'. The projection 30' is arranged to move in an arc with
the pintle 21' as the center from one end to the other of an
elongated arcuate slot 50 provided in a lateral projection 51 on
one side of the gear segment 20', the position of the projection
30' in the slot being determined by the position of the locking
pawl 27'. With the door in the closed position, pawl 27' has a lug
52 in locking position behind a lug 53 on the link 20'. However, in
the initial door opening movement, the locking pawl 27' has its lug
52 move clear of the lug 53 on the link so as to free the
projection 30' on the segmental gear to permit further door opening
movement to the extent permitted by the length of the arcuate slot
50, the locking pawl 27' at this point being free to swing about
its pivot 26' relative to the gear segment 20'. It is at the
intermediate position of the door, shown in FIG. 8, that pawl 27'
is unlocked at 52-53. Hence, as seen in FIG. 9, the door swings
farther open as the projection 30' moves outwardly to the outer end
of slot 50. In the initial closing movement of the door, pawl 27'
is swung around its pivot 26' into a position, as shown in FIG. 8,
where its lug 52 is ready to engage behind the lug 53 on link 24',
and hence, in the final closing movement of the door, the hinge
parts are interlocked as seen in FIG. 7. Here, again, there is a
stop 33' on the outer end of the body bracket 16' which, in the
closed position of the door, shown in FIG. 7, is spaced from the
outer corner portion 34' on gear segment 20'. However, in the
initial door opening movement the stop 33' on the body bracket 36'
comes into engagement with the corner portion 34' on the periphery
of the segmental gear 20' so as to hold the link 24' in a position
for swinging of the door about its inner end in the final door
opening movement.
The operation of this form is closely similar to the operation of
the form first described insofar as the upper hinge 11' is
concerned, so that the only additional comments necessary are in
regard to how the inclusion of the torsion bar 39 in the lower
hinge 12' affects the operation. Obviously, in the winding up of
the torsion bar 39 in the opening movement of the door, the
operator is aware of the spring restraint on the door's movement,
which is not enough to present any difficulty, of course, although
it does reduce the likelihood of the door being swung open too
violently, and that is, of course, desirable. Then, near the limit
of door opening movement the hold-open action takes place as the
end 45 of the torsion bar rides over first one and then the other
of the detent rollers 47 and 48. Then, in closing the door, the
spring action of the torsion bar 39 obviously gives an assist
action, but there, again, not enough to make the door closing
movement too violent. The line e-f in FIG. 7 is the center line of
the counterbalancing tension spring stretched between pintle 21'
and stop projection 33' that is given a certain preload tension so
as to be stretched further as the door swings toward closed
position from the intermediate open position of the parts shown in
FIG. 8 to the fully closed position of the parts shown in FIG. 7,
thereby avoiding slamming of the door by reason of its being on a
descent in this portion of its travel. Obviously, this spring
assists in the opening movement to an equal extent. A further
advantage is that it helps to eliminate rattle and a feeling of
looseness of the door when the hinge parts are in the part-way open
position of FIG. 8.
It is believed the foregoing description conveys a good
understanding of the objects and advantages of my invention. While
a preferred embodiment of the invention has been illustrated and
described, this is only for the purpose of illustration, and it is
to be understood that various modifications in structure will occur
to a person skilled in this art.
* * * * *