U.S. patent number 3,794,317 [Application Number 05/107,663] was granted by the patent office on 1974-02-26 for automatic swing.
This patent grant is currently assigned to Jenkintown Metal Products, Inc.. Invention is credited to Edmund Barrett.
United States Patent |
3,794,317 |
Barrett |
February 26, 1974 |
AUTOMATIC SWING
Abstract
A child's swing operated by a spring motor. The swing includes a
frame, upstanding legs supporting the frame and a swing seat
suspended from the frame. The spring motor includes a coiled spring
having one end secured to a ratchet wheel and the other end secured
to the frame. A pair of pawls alternately engage the ratchet wheel,
thereby controlling the release of the tension on the spring. The
power of the spring in turn drives the seat in a reciprocating
pivotal movement. The spring is formed from spring steel, and has a
square cross-section. By utilizing the square cross-section, a
spring of increased diameter can be used without the coils of the
spring skewing. The increased diameter of the main coiled spring
permits the swing to operate for at least twice as long as the
prior art automatic swings which were powered by coiled
springs.
Inventors: |
Barrett; Edmund (Narberth,
PA) |
Assignee: |
Jenkintown Metal Products, Inc.
(Jenkintown, PA)
|
Family
ID: |
26805015 |
Appl.
No.: |
05/107,663 |
Filed: |
January 19, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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885525 |
Dec 16, 1969 |
3667756 |
|
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Current U.S.
Class: |
472/119;
297/274 |
Current CPC
Class: |
A47D
13/105 (20130101); A63G 9/16 (20130101) |
Current International
Class: |
A63G
9/16 (20060101); A63G 9/00 (20060101); A63g
009/16 () |
Field of
Search: |
;272/85-91,83A,33
;185/37,39,45 ;297/5,8,274-282 ;46/29 ;287/83,110,115,118,114
;267/180 ;58/114 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Pinkham; Richard C.
Assistant Examiner: Brown; Theatrice
Attorney, Agent or Firm: Caesar, Rivise, Bernstein &
Cohen
Parent Case Text
This application is a continuation-in-part of my co-pending
Application Ser. No. 885,525, filed Dec. 16, 1969 now U.S. Pat. No.
3,667,756.
Claims
What is claimed as the invention is:
1. An automatic swing comprising a frame, a rod rotatably mounted
in said frame, a ratchet wheel secured to said rod, a coil spring
surrounding said rod, said coil spring being adapted to urge said
ratchet wheel in a rotational direction, a hanger bar suspended
from said rod, a seat supported by said hanger bar, said hanger bar
having a first pawl pivotally mounted thereon, a second pawl
pivotally mounted on said frame, said second pawl being urged into
contact with said ratchet wheel by spring means, said second pawl
being urged out of contact with said ratchet wheel when said first
pawl contacts said spring means, with said first pawl being engaged
by said ratchet wheel when said second pawl is urged out of
engagement with said ratchet wheel, and said second pawl being
returned to engagement with said ratchet wheel when said first pawl
is urged out of engagement with said ratchet wheel by the power
furnished by said coil spring, thereby pivoting said hanger bar on
said rod, said spring means comprising a leaf spring having two
arms, with the first of said arms being associated with said second
pawl and the second of said arms being mounted on said frame, said
first pawl having an arcuate lip that contacts said first arm to
move said second pawl out of contact with said ratchet wheel, with
said first arm urging said first pawl into contact with said
ratchet wheel when said second pawl is moved out of contact with
said ratchet wheel.
2. An automatic swing comprising a frame, a horizontal rod carried
by said frame, a seat suspended from said rod, a coiled tension
spring surrounding said rod, said coiled spring being adapted to
actuate a reciprocating pivotal motion to said seat around said
rod, means for winding said coiled spring to increase the tension
on the coils thereof, said coiled spring being formed from a wire
having flattened lateral faces, with said faces being adapted to
contact each other when the tension on said spring is increased by
winding said spring, whereby the flattened lateral faces prevent
the overlapping of the coils of said spring when they contact each
other during winding, a hanger bar suspended from said rod, said
seat being supported by said hanger bar, said hanger bar having a
first pawl pivotally mounted thereon a second pawl pivotally
mounted on said frame, a ratchet wheel secured to said rod, said
coiled spring being adapted to urge said ratchet wheel in a
rotational direction, said second pawl being urged into contact
with said ratchet wheel by spring means, said second pawl being
urged out of contact with said ratchet wheel when said first pawl
contacts said spring means, with said first pawl being engaged by
said ratchet wheel when said second pawl is urged out of engagement
with said ratchet wheel, and said second pawl being returned to
engagement with said ratchet wheel when said first pawl is urged
out of engagement with said ratchet wheel by the power furnished by
said coiled spring, thereby reciprocating said seat in said pivotal
motion, said spring means comprising a leaf spring having two arms,
with the first of said arms being associated with said second pawl
and the second of said arms being mounted on said frame, said first
pawl contacting said first arm to move said second pawl out of
contact with said ratchet wheel, with said first arm urging said
first pawl into contact with said ratchet wheel when said second
pawl is moved out of contact with said ratchet wheel, and said
first pawl including an arcuate lip, said arcuate lip contacting
said first arm.
3. An automatic swing comprising a frame, a horizontal rod carried
by said frame, a seat suspended from said rod, a coiled tension
spring surrounding said rod, said coiled spring being adapted to
actuate a reciprocating pivotal motion to said seat around said
rod, means for winding said coiled spring to increase the tension
on the coils thereof, said coiled spring being formed from a wire
having flattened lateral faces, with said faces being adapted to
contact each other when the tension on said spring is increased by
winding said spring, whereby the flattened lateral faces prevent
the overlapping of the coils of said spring when they contact each
other during winding, said seat being formed from a flexible body
and a frame, said frame comprising a pair of substantially U-shaped
rods, each of said rods having a pair of legs, with said legs of
one of said rods being aligned with the legs of the other of said
rods, said flexible body being secured to said frame, and said legs
having the aligned ends thereof received in a pair of sleeves, said
sleeves having means formed thereon for retaining said legs in
alignment and retaining said frame in its secured position with
respect to said flexible body, and said means for retaining said
legs in alignment comprising teeth projecting inwardly from said
sleeves into said legs, said teeth being unitary with said
sleeves.
4. The automatic swing of claim 3 wherein said teeth project into
said legs at an angle whereby an attempt to move said aligned legs
away from each other will cause said teeth to penetrate said legs.
Description
This invention relates to a child's swing, and more particularly,
to a child's swing that is powered by a spring motor.
Baby swings actuated by spring motors are now in common usage. The
motors are wound and the swing is then set in operation, and will
continue to reciproate in a small arc under the power of the spring
motor until the tension on the spring is fully unwound. Swings of
this type normally operate for 12 to 15 minutes each time the
spring is wound, and the swings serve to keep a young child
occupied and relaxed for this period of time. The swings are also
an aid in putting a young child to sleep.
One type of swing presently in use includes a spring motor that has
one end of the spring secured to a reciprocating cradle and the
other end secured to a shaft which is used to wind the spring. One
of the problems with this structure is that it has been found that
the fingers can be pinched by the cradle against the housing when
the swing is in operation, or when the spring motor is wound. This
occurs because one end of the spring was secured to the cradle, and
when the spring was wound, the cradle would suddenly be forced
against the housing.
In the device disclosed in my aforementioned Application Ser. No.
885,525, the problem of pinched fingers was obviated by providing
hanger bars which were freely rotatable on the rod used for winding
the spring, instead of having the cradle which is always under the
force of the spring. Accordingly, the hanger bars remain in a
substantially vertical orientation during the entire winding
operation. The hanger bar is propelled by the spring motor only
during the use of the swing.
The device of this invention provides a number of improvements over
the device disclosed in aforementioned Application Ser. No.
885,525. One of these improvements resides in the provision of an
enlarged diameter coiled spring for the spring motor. The diameter
of the spring is substantially larger than the diameter of the tube
on which the spring is wound. Accordingly, the spring requires a
greater number of turns to tighten the same against the tube. The
greater the number of turns of the spring, the longer it takes for
the spring to unwind. This, in turn, results in providing a
substantially longer period of operation for the swing each time
the spring is wound. It has been found that the increased diameter
spring permits an operating time of up to forty minutes for the
swing.
One of the problems encountered in the use of the enlarged diameter
spring was that the coils of the spring would skew or overlap
during the winding operation. This, in turn, caused the locking of
the spring and/or a point of weakness in the spring each time the
spring was wound. Eventually, the operating time of the spring
would be greatly reduced because of the locked coils, and in
addition, the spring would eventually break because of the fatigue
point at the skewed coil.
In order to overcome the problem of the skewing, a spring was
developed which was formed from spring wire having a square
cross-section. The abutment of the flat face of one coil with the
flat face of the adjacent coil prevented the skewing of the coils
during the winding of the spring. Thus, the round coils of the
prior spring had a tendency to slide over and under each other,
thereby resulting in the skewing. However, the flat sides of the
square wire coils abut each other during the winding operation, but
do not readily slide over each other. For this reason, the skewing
is eliminated.
Another improvement of the device of this invention resides in the
replacing of a hairspring with a leaf spring. The leaf spring is
used to urge one of the pawls into releasable engagement with the
ratchet wheel. During the operation of the swing, a second pawl is
brought to bear against the leaf spring, thereby taking the first
pawl out of engagement with the ratchet wheel. In the swing
disclosed in aforementioned Application Ser. No. 885,525, a
hairspring was used for this function. However, because of the thin
wire used in the hairspring, it was found that the hairspring could
fatigue during extensive periods of use. The leaf spring is far
stronger, and should undergo indefinite use without fatiguing.
A third improvement residing in the device of this invention is the
provision of an arcuate shoulder on the pawl which contacts the
leaf spring. In the device disclosed in aforementioned Application
Ser. No. 885,525, a sharp edge of the second pawl contacted the
hairspring during the operation of the spring. This sharp edge
could, in some instances, cause complete fatigue and failure of the
hairspring. By providing the arcuate shoulder, the pawl glides over
the leaf spring supporting the first pawl, and does not damage the
leaf spring at a given spot since the contact is over an enlarged
area.
A fourth improvement in the device of this invention resides in the
provision of a new frame for supporting the fabric seat of the
swing. In the prior art swings, the seat was supported by a pair of
side rods which had short flanges that were inserted in elongated
tubes at the front and rear of the fabric seat. It has been found
that it is extremely difficult to insert the flanges into the
tubes, and quite often the fabric of the seat was torn during the
insertion. Very little excess fabric was provided because the
tension of the fabric on the side rods maintained the flanges in
the tubes.
In the device of this invention, the elongated tubes are
eliminated, and in their place short sleeves are used. These
sleeves have gripping teeth which permanently secure the side rods
within the sleeves. Accordingly, the tension of the fabric on the
side rods is no longer necessary to maintain the seat frame in
place.
It is accordingly an object of this invention to provide a novel
automatic swing.
It is another object of this invention to provide an automatic
swing that is powered by a coiled spring, which swing will operate
for extensive periods of time each time the coiled spring is wound
to increase the tension thereof.
It is a further object of this invention to provide an automatic
swing having a novel seat assembly.
It is yet a further object of this invention to provide an
automatic swing having a novel pawl assembly.
These and other objects of this invention are accomplished by
providing an automatic swing comprising a frame, a horizontal shaft
carried by said frame, a seat suspended from said shaft, a coiled
spring surrounding said shaft, said coiled spring being adapted to
actuate a reciprocating motion to said seat around said shaft, said
coiled spring having a diameter which is substantially larger than
the diameter of said shaft, with the coils of said spring having
flattened lateral faces, and means for winding said coiled spring
to increase the tension of the coils thereof.
Other objects and many of the attendant advantages of this
invention will be readily appreciated as the same becomes better
understood by reference to the following detailed description when
considered in connection with the accompanying drawings
wherein:
FIG. 1 is a perspective view of an automatic swing embodying the
present invention;
FIG. 2 is an enlarged sectional view taken along the line 2--2 of
FIG. 1;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2;
FIG. 4 is a sectional view similar to FIG. 3, but showing the
position of the pawls at one end of the arc of the hanger bar;
FIG. 5 is a sectional view similar to FIG. 4, but showing the
position of the pawls at the other end of the arc of the hanger
bar;
FIG. 6 is an exploded perspective view of the elements of the
escapement mechanism for the ratchet wheel;
FIG. 7 is a perspective view of the seat of the automatic swing
embodying the present invention;
FIG. 8 is a partial perspective view of the front of the seat
during the assembly of the seet;
FIG. 9 is a partial perspective view of the securement mechanism
for the rods of the seat;
FIG. 10 is a sectional view taken along the line 10--10 of FIG.
9;
FIG. 11 is a perspective view of the coiled spring used in the
swing of this invention; and
FIG. 12 is an enlarged sectional view taken along the line 12--12
of FIG. 11.
Referring now in greater detail to the various figures of the
drawings wherein like reference characters refer to like parts, an
automatic swing embodying the present invention is generally shown
at 10 in FIG. 1. Device 10 basically comprises a frame 12 having
supporting legs 14 and a seat 16 suspended therefrom.
Frame 12 comprises an upper housing 18 and a lower housing 20
secured thereon. Upper housing 18 includes a top plate 22, side
plates 24 which flare outwardly (FIG. 2), a front plate 26 (FIG. 3)
and a rear plate 28. Braces 30 extend from rear plate 28 to front
plate 26 and are riveted to the front and rear plate, as shown at
32 with respect to rear plate 28 in FIG. 2. As seen in FIG. 2, the
braces 30 have one surface that lies in a plane parallel to side
plates 24. The side plates 24 are spaced from braces 30 a distance
equal to the diameters of the legs 14, and the legs are mounted
between braces 30 and side plates 24 by sheet metal screws 34 (FIG.
2). Braces 30 also include openings 36 on the sides which are
parallel to end plates 24.
Legs 14 are formed from tubular steel, and as seen in FIG. 1, flare
outwardly from the frame 12. The flaring is accomplished because
the plates 24, 26 and 28 all taper outwardly in going from top
plate 22 downward. Having the flared positioning of the legs
provides a more stable structure when a child is supported in the
swing, and prevents the inadvertent tipping of the swing. Rubber or
plastic end caps 38 are placed at the bottoms of the legs. Legs 14
are pivotable about screws 34 for collapsing the swing, and are
held in the open position by side straps 39 (FIG. 1).
Mounted within housing 18, and forming a part of the frame, is a
pair of supporting plates 40. Each supporting plate 40 is
vertically extending within housing 18, and includes an upper
flange 42 which is mounted against top plate 22 of housing 18. Each
plate 40 further includes a pair of side flanges 44 which are
riveted to front and rear plates 26 and 28 of housing 18 (FIG. 3),
as shown at 45. Each plate 40 further includes a first bottom
flange 46 (FIG. 6) and a second bottom flange 48 (FIG. 2). As seen
in FIG. 2, since plates 40 are arranged in a position whereby they
face each other, the bottom flange 48 of one plate 40 will be
aligned with the bottom flange 46 of the other plate 40. Each plate
40 is provided with an outstruck opening 50 (FIG. 2).
A horizontally extending rod 52 is received in outstruck openings
50 of plates 40. One end of rod 52 is held within frame 12 by clip
54 formed of spring steel. Rod 52 passes through opening 36 in one
of the braces 30 and through opening 56 in an end plate 24. A crank
arm 58 is formed at the end of rod 52, and a knob 60 (FIG. 1) is
rotatably mounted on the end of arm 58.
As seen in FIG. 2, rod 52 is provided with a pinched portion 62
adjacent one end thereof. The pinched portion forms a pair of
aligned outwardly projecting lips in the rod. Openings 50 in plates
40 are provided with aligned slots 64 (FIG. 6) to permit the
pinched portion 62 of rod 52 to pass therethrough. A ratchet wheel
66 is provided with a pair of slots 67 (FIG. 6) which receive the
pinched portion 62 of the rod thereby keying the ratchet wheel to
the rod. Ratchet wheel 66 contains a plurality of equally spaced
ratchet teeth 68 around its circumference.
A tube 70 is telescoped over rod 52 and is mounted between ratchet
wheel 66 and one supporting plate 40. One end of tube 70 is secured
by a collar 72 which is riveted to plate 40, as shown at 74. A
second collar 76 is riveted to ratchet wheel 66, as shown at 78.
Tube 70 includes outstruck tabs 80 which are used for the alignment
of rod 52 when it is passed through tube 70 during the assembly of
the swing. Thus, the tabs 80 insure that the rod 52 will pass
through the opening in ratchet wheel 66 during the assembly
process.
A coiled tension spring 82 is telescoped over tube 70. One end 84
of the tension spring is rigidly mounted with respect to plate 40
by rivet 74. The other end 86 of spring 82 is rigidly mounted with
respect to ratchet wheel 66 by rivet 78.
The lower housing section 20 is mounted on the bottom of upper
housing section 18 by riveting it to flanges 46 and 48 of plates 40
(FIG. 2). Lower housing section 20 is not shown in FIGS. 3, 4 and 5
for the purpose of clarity. A slot 88 is formed in lower housing
section 20, as seen in FIG. 2. A hanger bar 90 having a central
horizontal section 92 and vertically extending arms 94 and 96 is
suspended from rod 52 by passing the rod through holes formed in
arms 94 and 96. Arm 94 is received in slot 88 of lower housing
section 20. Arm 96 is positioned between plate 40 and a side brace
30, beyond the outer edge of lower housing section 20.
Hanger bar 90 is formed from a tube, with the horizontal section 92
being retained in a tubular shape. The ends of the tube are
flatened in order to form vertical arms 94 and 96. A pair of hanger
rods 98 (FIG. 1) is supported by horizontal section 92 of hanger
bar 90. Each rod 98 includes an upper bent portion 100 (FIG. 3)
that passes through a pair of aligned holes in hanger bar 90.
Horizontal section 92 includes an upwardly projecting slot 102
(FIG. 3) beneath the holes formed for bent portions 100. A chain
104 (FIG. 1) passes upwardly through each slot 102 and is received
on the bent portion 100 of each rod 98. The rod then passes through
the front of horizontal tube 92 where it is held in place by a cap
106.
Rods 98 and chains 104 support seat 16. The seat comprises a
flexible body supporting section 108 and a metal frame 110. The
specific structure of the metal frame and its assembly will be
explained hereinafter. The seat is supported by the placing of the
metal frame sections in hooks 112 of rod 98 and in one of the links
of chains 104.
Vertical arm 94 of hanger bar 90 has a pawl 114 (FIG. 6) mounted
thereon. Pawl 114 includes a plate 116 that is pivotally mounted on
arm 94 by rivet 117. A flange 118 projects perpendicularly from
plate 116. Flange 118 in turn includes a downwardly projecting
arcuate lip 119. Arm 94 includes an outstruck tab 120 (FIGS. 3 to
6) on which pawl 114 rests.
A second pawl 122 (FIG. 6) is mounted on plate 40 which is adjacent
ratchet wheel 66. Pawl 122 includes a plate 124 which is pivotally
mounted on plate 40 by rivet 126. A flange 128 projects from plate
124. A leaf spring 130 (FIG. 6) has one arm 132 received in
outstruck loops 134 on flange 46 of plate 40 adjacent ratchet wheel
66. The other arm 136 of spring 130 is received in an opening
formed in flange 128 of pawl 122. The spring 130 urges pawl 122 in
a clockwise direction, as viewed in FIG. 6, around rivet 126.
In FIG. 7, the seat 16 is shown in detail in its assembled
condition. As pointed out above, the seat includes a flexible body
108 which can be formed from cotton duck, canvas or plastic.
Suitable leg holes 138 are formed in the body. The body also
includes a plurality of spaced looped sections 140 through which
the frame 110 passes.
Frame 110 comprises a pair of substantially U-shaped rods 148 which
include legs 150 at the top and bottom of the seat and a bridging
section 152 on the sides of the seat. As seen in FIGS. 1 and 7, the
bridging sections 152 are angled at the center in order to form the
contour of the seat. The rods 148 are received in looped sections
140 of the body of the seat.
In assembling the seat, the rods are threaded through the looped
sections 140. At the same time, the chains 104 and hooks 112 of
rods 98 are threaded in place. If desired, ornamental discs, such
as discs 154 (FIG. 7) can also be threaded on the rods. The ends of
the legs of the two rods are in alignment in the area of the spaces
156 between the upper and lower looped sections 140. The aligned
ends of the rods are secured together by the use of a sleeve 158.
As best seen in FIGS. 8, 9 and 10, each sleeve 158 has a central
opening 160 formed therein. Outstruck teeth 162 project inwardly
adjacent opening 160.
In the securement of the ends of rods 150, one rod 150 is inserted
into sleeve 158 until its end is positioned in the center of
opening 160. Thereafter, the end of the other rod 150 is inserted
in sleeve 158, and a force is applied against the bridging section
of the other rod. This force can be the force of a hammer while the
first rod is held stationary. This brings the two ends of the rods
into abutment within sleeve 158 as shown at 164 in FIG. 9. As seen
in FIG. 10, the two ends of the rods 150 are permanently secured
within sleeve 158 by the engagement of teeth 162 into the rods.
Thus, any attempt to separate the rods will only cause the teeth
162 to bite further into the rods.
The other two ends of the rods 150 are secured in the same manner
as that shown in FIGS. 8 to 10. Accordingly, once the rods have
been inserted in the sleeves 158, they are held rigidly in place,
thereby forming a permanent frame for the seat body 108.
The coiled spring 82 is shown in perspective in FIG. 11. As seen
therein, the spring includes a central section 166 of a constant
diameter and tapering end sections 168. As seen in FIG. 2, the
coils of the spring are closely spaced in the assembled condition
of the swing. As seen in FIG. 12, the spring is formed from a wire
having a square cross-section. The critical feature of the spring
used in the swing of this invention is that the sides of the coils
be flat, whereby the flat sides of adjacent coils will abut each
other. As pointed out above, having the flat sides prevents the
overlapping or skewing of the coils during the winding of the
spring.
The device of this invention is used by first winding crank arm 58
in a clockwise direction, as viewed in FIG. 1. Since ratchet wheel
66 is keyed to rod 52, the rotation of the crank arm will cause the
ratchet wheel to rotate in a clockwise direction, as viewed in
FIGS. 3 to 6. During the rotation of the ratchet wheel, flange 128
of pawl 122 will be moved out of engagement with the ratchet teeth
68 in view of the shape of the ratchet teeth, which permit the
winding in a clockwise direction. However, whenever the winding is
stopped, flange 128 will engage the forward edge of a ratchet tooth
under the urging of spring 130. Pawl 114 will be slightly removed
from the ratchet teeth during the winding of the crank arm 58. In
this connection, it should be noted that arms 94 and 96 of hanger
bar 20 are freely pivotally mounted on rod 52. Accordingly, when
the rod 52 is turned, thereby turning ratchet wheel 66, the arms 94
and 96 will remain substantially vertical. When in the vertical
orientation, the pawl 114 is slightly removed from the ratchet
teeth 68.
The turning of the ratchet wheel 66 will in turn place a tension on
coiled spring 82, since one end of the coiled spring is rigidly
mounted with respect to the ratchet wheel by rivet 78 and the other
end 84 of the coiled spring is rigidly mounted on plate 40. The
winding of the spring supplies the moving force for the spring
motor comprising the spring, ratchet wheel and the pawls. The sping
is prevented from unwinding by the engagement of pawl 122 in
ratchet teeth 68. The fact that the hanger bar is not moved during
the winding of the spring is one of the advantages of the swing of
this invention. In the prior art, the spring had one end secured to
a cradle which supported the spring. Accordingly, when the spring
was wound, the cradle immediately was forced against the housing,
thereby presenting the possibility of pinching any fingers that
were within the housing. Since all of the elements which are
directly controlled by the spring are maintained within bottom
housing 20, which is rigidly mounted in place, there is no danger
of injury at the time the spring is wound.
After the spring is wound, hanger bar arm 94 will be in the
position shown in FIG. 3. During the operation of the swing, hanger
bar arms 94 and 96 will reciprocate in the form of a pendulum, as
shown by arrow 170 in FIG. 6. The reciprocation of the hanger bar
arms will in turn reciprocate the swing seat 16 holding the baby,
as indicated by arrow 172 in FIG. 1.
After the spring has been wound, the swing action is initiated by
pushing the hanger bar in a clockwise direction, as viewed in FIG.
3. Referring now to FIG. 5, the action of the hanger bar when
pushed forward is seen. Thus, during the forward motion, arcuate
lip 119 of flange 118 engages arm 136 of spring 130. The lip glides
upwardly on the arm 136 thereby depressing the arm. At the same
time, the arm 136 rotates pawl 114 in a clockwise direction around
rivet 117, thereby engaging the flange 118 in a ratchet tooth 68.
At the same time, flange 128 of pawl 122 is rotated out of
engagement with a ratchet tooth 68. With the pawl 122 removed from
the ratchet wheel, the tension on spring 82 causes the ratchet
wheel to rotate in a counterclockwise direction. This in turn
pushes arm 94 in a counterclockwise direction by the pressure of
the ratchet tooth against pawl 114. Accordingly, pawl 114 is moved
to the position shown at 114' in FIG. 5.
As the arm 94 is moved in a counterclockwise direction, the
pressure against spring arm 136 is removed, and flange 128 will
re-engage a ratchet tooth 68. The pressure of the spring against
pawl 114 while the flange 128 is disengaged from ratchet wheel 66
is sufficient to swing arm 94 to the position shown in FIG. 4.
Since the swing seat 16 depends from the hanger bar 90, the swing
seat will be carried backward along with the arm 94 and the
remainder of the hanger bar 90.
On the counterclockwise swing of arm 94, pawl 114 is completely
free of ratchet teeth 68. This is because the pawl is freely
pivotable on arm 94 around rivet 117, and gravity will hold the
pawl in the position shown in FIG. 4 against outstruck tab 120.
Accordingly, it is unnecessary to have any spring tension on the
pawl 114, as would be necessary when utilizing the prior art
structures.
After the spring force has carried the hanger bar to the position
shown in FIG. 4, the force of gravity will rotate the hanger bar in
the opposite direction. On the return movement, pawl 114 will again
engage spring arm 136, thereby freeing flange 128 from a ratchet
tooth, and engaging flange 118 in a new ratchet tooth. The arm 94
will again be returned to the position shown in FIG. 4 in the
manner described above, thereby swinging seat 16 in a
counterclockwise direction.
During one full reciprocation of arm 94, the ratchet wheel 16 will
be advanced a rotational amount equal to one ratchet tooth. Thus,
each time pawl 122 is removed from the ratchet wheel, it is
returned to the next successive ratchet tooth. This controlled
escapement of the tension on spring 82 permits the swing to be used
for periods of time of approximately forty minutes each time the
spring is wound.
The reason the swing of this invention can operate for
approximately 40 minutes, whereas the prior art spring motor swings
could operate for a maximum period of time of only fifteen minutes,
resides in the provision of spring 82. As best seen in FIG. 12, the
spring is formed from wire having a square cross section.
Accordingly, flat faces are provided for each of the coils. During
the winding of the spring, the diameter of the spring is reduced
until the spring is tightly wound on tube 70. This brings the coils
of the spring into abutment. However, the flat faces of the coils
prevent the skewing of adjacent coils. In the prior art springs,
the coils were all circular in cross section, and skewing presented
a serious problem. Thus, if the coils became skewed or overlapped,
weakness developed in the spring, and in addition, the running time
of the swing was substantially reduced. Eventually, the spring
could break because of the weakness formed by the skewed coils.
Because skewing is substantially eliminated by having the square
coils, a greater number of coils can be provided in the same space
utilized for the prior art springs having coils of a circular cross
section. The greater the number of coils in a given length, the
longer the swing will operate. By way of specific example, spring
82 is formed from square steel wire having a width of 0.062 inch.
The outer diameter of section 166 of the spring is 1 9/16 inches.
This section of constant diameter is 7 1/2 inches in length. The
tapering sections 168 are each 1 inch in length, and the smallest
outer diameter of the spring is 1 3/16 inches. Accordingly, the
spring tapers from an outer diameter of 1 9/16 inches to an outer
diameter of 1 3/16 inches over a space of 1 inch. The spring is
stretched to a length of 13 5/8 inches when secured in the housing
18 in the manner shown in FIG. 2.
The foregoing dimensions are by way of example only. The dimensions
can be varied to suit the needs of the user for a specific swing.
The critical feature, however, of the spring is that the coils have
flat lateral faces. By having these flattened faces, a
substantially greater number of coils can be provided for a given
unit of length in the swing. This in turn results in greater
running time for the swing.
Another feature of the swing of this invention resides in seat 16.
The use of short tube 158 to secure the ends of rods 148 in place
provides a distinct advantage over the tubes used in the prior art
swings. In the prior art, tubes were used which extended over
substantially the entire width of the front and back of the swing.
The legs 150 of the prior art rods were extremely short, and had to
be forced into the ends of the tubes by stretching the fabric of
the seat. The tension of the fabric of the seat against the rods
held the ends of the rods in the tubes. One of the problems
encountered was that the fabric was not resilient enough to always
permit the ends of the rods to be inserted in the tubes with any
degree of ease. Accordingly, quite often the fabric of the seat was
torn during the insertion.
In the seat of this invention, the tension of the fabric body of
the seat plays no part in the securement of the rods in the tubes
158. The ends of the rods are held in the tubes solely by the
engagement of pointed teeth 162 in the rods, as shown in FIG. 10.
An excess of fabric is provided in the seat to enable the ends 150
of the rods to easily be inserted into the tubes 158. The fabric of
the seat is not needed to hold the rods in place, and therefore the
fabric need not be taut. This greatly facilitates the assembly of
the seat.
Another improvement of the swing of this invention is the provision
of arcuate lip 119. This lip glides against leg 136 of spring 130
during the operation of the swing. Contrasted with this, in the
swing disclosed in my aforementioned co-pending Application Ser.
No. 885,525, a sharp edge of flange 118 would strike the spring at
a single point, thereby fatiguing the spring at that point.
Another improvement of the swing of this invention is the provision
of leaf spring 130 instead of the hairspring used in the swing of
my co-pending Application Ser. No. 885,525. The leaf spring is much
stronger in construction, and should last far longer than the thin
wire hairspring of my prior swing.
Without further elaboration, the foregoing will so fully illustrate
my invention, that others may, by applying current or future
knowledge, adopt the same for use under various conditions of
service.
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