U.S. patent number 3,594,852 [Application Number 04/680,518] was granted by the patent office on 1971-07-27 for pin hinge.
This patent grant is currently assigned to Westhem Corporation Limited. Invention is credited to Alois Albin Krawagna.
United States Patent |
3,594,852 |
Krawagna |
July 27, 1971 |
PIN HINGE
Abstract
A snap hinge which includes a plate member pivoted to a rigid
member. Extending from the plate member at a location spaced from
the first pivot is a resilient arm the end of which is integral
through a flexible web with a connecting arm. The other end of the
connecting arm is pivoted to the rigid member at a point spaced
from the plate member pivot. Depending on the distance between the
pivots, the snap hinge has either one or two at-rest positions.
Inventors: |
Krawagna; Alois Albin
(Willowdale, Ontario, CA) |
Assignee: |
Westhem Corporation Limited
(Toronto, Ontario, CA)
|
Family
ID: |
24731437 |
Appl.
No.: |
04/680,518 |
Filed: |
November 3, 1967 |
Current U.S.
Class: |
16/227 |
Current CPC
Class: |
E05F
1/1284 (20130101); F16H 35/14 (20130101); Y10T
16/5257 (20150115) |
Current International
Class: |
E05F
1/12 (20060101); F16H 35/00 (20060101); E05F
1/00 (20060101); F16H 35/14 (20060101); E05d
007/00 () |
Field of
Search: |
;16/150,128B
;220/31 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gay; Bobby R.
Assistant Examiner: Troutman; Doris L.
Claims
What I claim as my invention is:
1. A snap-hinge comprising:
a plate member,
a rigid member to which the plate member is pivotally mounted by a
first pin-and-socket connection defining a first pivot axis,
a resilient arm integral with said plate member and extending
therefrom at a location spaced from said first pivot axis, the
resilient arm tending to seek a given position with respect to said
plate member,
a connecting arm integral through a flexible web with a portion of
the resilient arm spaced from the plate member,
said connecting arm being pivotally mounted to said rigid member at
a location remote from said flexible web by a second pin-and-socket
connection defining a second pivot axis,
said web constituting a hinge axis which is spaced from said first
pivot axis when said resilient arm is in said given position,
the rigid member maintaining said first pivot axis separated from
said second pivot axis by a distance which is less than the
distance between said second pivot axis and said hinge axis.
2. A snap hinge as claimed in claim 1, in which said resilient arm
in said given position defines an acute angle with the hypothetical
line joining said first pivot axis and said location.
3. A snap hinge as claimed in claim 2, in which said plate member,
said resilient arm and said connecting arm are made of
polypropylene.
4. A snap hinge as claimed in claim 2, in which said plate member
has at least one cylindrical pin projecting therefrom at each pivot
axis, the rigid member having socket-defining means for receiving
all cylindrical pins.
5. A snap-hinge comprising:
a plate member,
a rigid member to which the plate member is pivotally mounted by a
first pin-and-socket connection defining a first pivot axis,
a resilient arm integral with said plate member and extending
therefrom at a location spaced from said first pivot axis, the
resilient arm tending to seek a given position with respect to said
plate member,
a connecting arm integral through a flexible web with a portion of
the resilient arm spaced from the plate member,
said connecting arm being pivotally mounted to said rigid member at
a location remote from said flexible web by a second pin-and-socket
connection defining a second pivot axis,
said web constituting a hinge axis which is spaced from said first
pivot axis when said resilient arm is in said given position,
the rigid member maintaining said first pivot axis separated from
said second pivot axis by a distance which is greater than the
distance between said second pivot axis and said hinge axis.
6. A snap hinge as claimed in claim 5, in which said resilient arm
in said given position defines an acute angle with the hypothetical
line joining said first pivot axis and said location.
7. A snap hinge as claimed in claim 6, in which said plate member,
said resilient arm and said connecting arm are made of
polypropylene.
8. A snap hinge as claimed in claim 6, in which said plate member
has at least one cylindrical pin projecting therefrom at each pivot
axis, the rigid member having socket-defining means for receiving
all cylindrical pins.
Description
This invention relates to biased hinges, or "snap-hinges" as they
are sometimes called, in which the hinge tends to hold itself in
either the closed position or the open position, or both
positions.
The object of this invention is to provide a two-part, biased hinge
in which the biasing structure is incorporated integrally into one
of the two parts, the other of the two parts being merely a rigid
member.
Accordingly, this invention provides a snap hinge comprising: a
plate member having a first pivot, a resilient arm integral with
said plate member and extending therefrom at a location spaced from
said first pivot, the resilient arm tending to seek an unstressed
position with respect to said plate member, a connecting arm
integral through a flexible web with a portion of the resilient arm
spaced from the plate member, said connecting arm having a second
pivot remote from said flexible web, said web portion constituting
a hinge axis which is space d from said first pivot when said
resilient arm is in said unstressed position.
Two embodiments of the present invention are shown in the
accompanying drawings, in which like numerals refer to like parts
throughout the several views, and in which:
FIG. 1 is a perspective view of one embodiment of this
invention;
FIGS. 2, 3, 4 and 5 are sectional views, taken at the line A-A of
FIG. 1, showing sequential rotational positions of the first
embodiment of this invention; and
FIGS. 6, 7, 8 and 9 are sectional views, similar to FIGS. 2 to 5,
of the second embodiment of this invention.
Turning first to FIG. 1, the first embodiment of this invention is
seen to include a first part 10 and a second part 11. The first
part 10 consists of a plate member 12, which is shown to be
substantially in the shape of a tuning fork, although any other
suitable shape can be used. The plate member 12 thus has two arms
14 and a base 16. The plate member 12 has a first pivot 18 defined
by two integral, aligned bosses 20, one projecting outwardly from
either arm 14. Integral with the plate member 12 and extending from
the plate member between its two arms 14 is a resilient arm 22. The
resilient arm 22 extends from the plate member 12 at a location 23
spaced rightwardly from the pivot 18, and is constructed such that
it tends to seek an unstressed position with respect to the plat
member 12, this unstressed position being shown in dotted lines in
FIG. 2. In the latter Figure it will be noted that the resilient
arm 22 in its unstressed position forms an acute angle with
hypothetical line extending between the pivot 18 and the location
23 at which the resilient arm extends from the plate member 12.
A connecting arm 25 is integral with the resilient arm 22 through a
flexible web 26. The flexible web 26 is remote from the location 23
at which the resilient arm 22 extends from the plate member 12, and
constitutes a hinge axis between arms 22 and 25.
The connecting arm 25 has a pivot 28 at its end remote from the
flexible web 26, and the pivot 28 is define by two cylindrical
extensions 30, one projecting from either side of the connecting
arm 25.
In FIG. 1, the second part of the hinge has been shown as a single,
rigid disc 32 having a central aperture 33 and a plurality of
eccentric apertures 34 all equidistant from the central aperture
33. The second part 11 actually consists of two such discs 32, but
the nearer one has not been shown, in order to permit the structure
of the first part 10 to be viewed. The bosses 20 are adapted to
enter the apertures 33 in the discs 32, and the cylindrical
extensions 30 are adapted to lodge in particular ones of the
eccentric apertures 34 of the discs 32. The discs 32 are identical,
and they are fixed with respect to each other in such a way that
the apertures 33 and 34 correspond in pairs and are coaxial.
The ends of the arms 14 have curved seating portions 36 which are
adapted to rest against the extensions 30 and thereby provide a
limit to the counterclockwise rotation of the plate member 12 about
the pivot 18. The limit-providing property of the curved portions
36 is best seen in FIG. 2. When the plate member 12 is in the FIG.
2 position, and the bosses 20 and projections 30 are lodged in
appropriate apertures 33 and 34, the length of the connecting arm
25 and the distance between the apertures 33 and 34 are such that
the resilient arm 22 is flexed to some degree toward the bosses 20.
The degree of flexure is that between the dotted line and solid
line positions of the resilient arm 22 in FIG. 2. Thus, when the
plate member 12 is in the FIG. 2 position, the resilient arm 22 is
pulling upwardly and rightwardly on the pivot 28 through the medium
of the connecting arm 25. This slight tension of the resilient arm
22 tends to maintain the plate member 12 in the FIG. 2 position,
and can be said to bias the plate member 12 to the FIG. 2
position.
Attention is now directed to the sequential FIGS. 2, 3, 4 and 5, in
which the biasing action of the first embodiment of this invention
is shown. The first embodiment of this invention is one wherein the
plate member 12 is adapted to be biased into two positions, the
first one being that shown in FIGS. 1 and 2, the second position
being that shown in FIG. 5, which is almost 180.degree. rotated
from the position of FIG. 2. The plate member 12 is pivoted to the
discs 32 about the pivot 18, and downward pressure on the base 16
of the plate member 12 will begin to rotate the plate member in the
clockwise direction about the pivot 18. FIG. 3 shows the plate
member 12 rotated approximately 60.degree. clockwise from the
position in FIG. 2. It will be noted that the resilient arm 22 is
flexed further toward the pivot 18 in FIG. 3 than it is in FIG.
2.
Attention is now directed to the line 40 which is the hypothetical
line along which tension in the connecting arm 25 is directed. It
will be noted that, in FIG. 2, the line 40 lies well away to one
side of the pivot 18. As the plate member 12 reaches the FIG. 3
position, the hypothetical line 40 moves closer to the pivot 18,
but still remains on the same side of the latter. Because the line
40 is still on the same side of the pivot 18, the effect of the
spring action in the resilient arm 22 will remain one of biasing
the plate member counterclockwise towards the FIG. 2 position. It
will be noted however, that when the plate member 12 reaches the
FIG. 4 position, the hypothetical line 40 is coincident with the
pivot 18, and it is in this position that the biasing action of the
resilient arm 22 is completely nullified. In effect, when the plate
member 12 reaches the FIG. 4 position, it is in a state of unstable
equilibrium. If the plate member 12 is now moved further in the
clockwise direction, the line 40 will pass to the other side of the
pivot 18, and the effect of this will be to bias the plate member
12 towards the FIG. 5 position, where the resilient arm 22 and the
connecting arm 25 are in contact to establish a clockwise limit to
the rotation of the plate member 12. It will be noted that the
resilient arm 22 is flexed the most when the hypothetical line 40
coincides with the pivot 18 in FIG. 4, and that the resilient arm
22 comes back some distance in FIG. 5 towards its unstressed
position (dotted lines in FIG. 2).
It is considered that the principal criterion which determines that
the hinge will function in the way just described with reference to
FIGS. 2 to 5 is that the discs 32 maintain the pivot 18 separated
from the pivot 28 by a distance which is less than the distance
between the pivot 28 and the web 26, i.e., the interpivot distance
is less than the effective length of the connecting arm 25.
The operation of the hinge when the length of the connecting arm 25
is less then the distance between the pivots 18 and 28 is shown in
FIGS. 6 to 9, and this constitutes the second embodiment of this
invention. The second embodiment is one which is only biased in one
direction, and which never reaches the null point beyond which it
is biased in the other direction. Looking first at FIG. 6, the
unstressed position for the resilient arm 22 is again shown in
dotted lines, the plate member 12 is again adapted to pivot about
the pivot 18, the connecting arm 25 (visibly shorter than the
distance between the pivots 18 and 28) is again integral with the
resilient arm 22 through a web portion 26, and tension in the
connecting arm 25 is exerted along a hypothetical line 40. As the
plate member 12 is rotated in the clockwise direction about the
pivot 18, it reaches the FIG. 7 position. It will be noted that the
resilient arm 22 is more greatly flexed in FIG. 7 than in FIG. 6,
and that the hypothetical line 40 remains on the same side of the
pivot 18. Further rotation of the plate member 12 brings it to the
FIG. 8 position, in which the resilient arm 22 is flexed completely
across to the other side of the plate member 12, and that the
hypothetical line 40 is still on the same side of the pivot 18.
Further rotation brings the plate member 12 to the FIG. 9 position,
where the resilient arm 22 is very greatly stressed, the
hypothetical line 40 still remaining on the same side of the pivot
18. Because the hypothetical line 40 never crosses the pivot 18,
the plate member 12 is always biased in the counterclockwise
direction with respect to the discs 32, with a biasing effect which
grows greater with every degree of clockwise rotation of the plate
member 12, due to the increasing flexure of the arm 22.
The first and second embodiments of this invention can be compared
in terms of moment arms by considering that the discs 32 are
exerting a leftward force on the projections 30 along the
hypothetical line 40, and that this leftward force along the line
40 is transmitted to the entire plate member through the resilient
arm 22. The moment arm at any given point is the product of the
perpendicular distance from the pivot 18 to the line 40 and the
force exerted by the connecting arm 25 on the discs 32. As the
plate member reaches the FIG. 3 position, the force has increased
due to the greater flexing of the arm 22, but the perpendicular
distance from the pivot 18 to the line 40 has decreased, so that
their produce may be greater or smaller than in FIG. 2. In FIG. 4,
however, the distance from the pivot 18 to the line 40 is zero, so
that the moment arm itself is zero, which gives rise to the
unstable equilibrium described above. In FIG. 5, the pivot 18 is
again a finite distance from the line 40, and a moment arm is
thereby created. However, since the line 40 is now on the other
side of the pivot 18, the sense of the moment arm will change. In
the second embodiment, shown in FIGS. 6 to 9, since the line 40
never crosses the pivot 18, the moment arm never changes direction,
and the plate member 12 is always biased in the counterclockwise
direction about the pivot 18.
By using the first embodiment of this invention, and by slightly
altering certain portions of the assembly, there can be provided an
"on-off" switch in which the "on" position can be selected from a
number of radial positions around the discs 32. As shown in FIG. 1,
the connecting arm 25 is forked in such a way that the projections
30 can be moved toward one another under pressure. The outer ends
of the projections 30 are made hemispherical, and the apertures 34,
equally spaced from the aperture 33, are replaced by hemispherical
depressions. Thus, when the plate member 12 and the two discs 32
are assembled, the bosses 20 engage, as before, the apertures 33,
but the projections 30 are wedged into a pair of hemispherical
depressions 34. The projections 30 can be moved from any given pair
of hemispherical depressions to the next adjacent pair of
hemispherical depressions merely by applying pressure at the end of
the base 16 of the plate member 12. For example, when the assembly
is in the situation of FIG. 2, the projections 30 can be moved to
the next counterclockwise pair of hemispherical depressions by
exerting pressure upwardly on the rightward end of the base 16 of
the plate member 12. When the plate member is in the FIG. 5
position, the projections 30 can be moved to the next clockwise
pair of hemispherical depressions by pushing upwardly on the outer
(now leftward) end of the plate member 12.
It will be appreciated that the elements of the hinge assembly
herein disclosed do not need to be identical to those shown. In
particular, the discs 32 can be replaced by a single plate member
having sockets into which the bosses 20 and the projections 30 can
be received.
While preferred embodiments of this invention have been disclosed
herein, those skilled in the art will appreciate that changes and
modifications may be made therein without departing from the spirit
and scope of this invention as defined in the appended claims.
* * * * *