Field of Search:
272/85-91,83A,33 185/37,45 297/5,8,274-282 46/29 287/83,110,115,118,114 58/114 267/180
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to spring motor driven cradles and the like and more particularly to an improved spring construction with which greatly extended time of operation is obtained.
2. Brief Description of the Prior Art
Spring motor driven cradles and swings have heretofore been proposed.
One such swing is shown in U.S. Pat. No. 2,807,309 to Saint et al., and improvements thereon are shown in U.S. Pat. Nos. 3,059,725 and 3,071,339.
These devices have been well received but the length of time of operation is limited before rewinding is required and normal operation of those swings is of the order of fifteen minutes.
Various suggestions have been made to increase the operating time but these have not proven satisfactory and have still only permitted brief periods of operation.
SUMMARY OF THE INVENTION
In accordance with the invention an improved power spring construction is provided, using inner and outer series connected spring sections, the connections between the spring sections being effected by a rotatable coupling member movable longitudinally axially with the spring sections, the spring construction providing a greatly increased period of operation and with protection against overwinding.
It is the principal object of the invention to provide a power operated cradle or swing which is spring actuated, and in which the duration of operation is greatly increased.
It is a further object of the invention to provide a power operated cradle or swing which is simple in construction, reliable in its operation and free from problems for the user.
It is a further object of the invention to provide a power operated cradle or swing having an improved power spring construction.
Other objects and advantageous features of the invention will be apparent from the description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature and characteristic features of the invention will be more readily understood from the following description taken in connection with the accompanying drawings forming part hereof, in which:
FIG. 1 is a longitudinal vertical sectional view of the motor operating portion of a cradle or swing;
FIG. 2 is a transverse vertical sectional view, enlarged, taken approximately on the line 2--2 of FIG. 1;
FIG. 3 is a fragmentary vertical sectional view taken approximately on the line 3--3 of FIG. 2;
FIG. 4 is a transverse vertical sectional view taken approximately on the line 4--4 of FIG. 3;
FIG. 5 is an exploded perspective view of the drive shaft ratchet wheel, the spring sections and the spring coupler;
FIG. 6 is a fragmentary perspective view of the spring section coupler showing the engagement of the spring sections and the coupler;
FIG. 7 is a fragmentary perspective view of the spring coupler and outer spring section; and
FIG. 8 is a vertical sectional view, enlarged, taken on the line 8--8 of FIG. 1.
It should, of course, be understood that the description and drawings herein are illustrative merely and that various modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.
Like numerals refer to like parts throughout the several views.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings a canopy 10 is shown, preferably of sheet metal supported in any desired manner, such as by pairs of diverging tubular supporting legs 11 at each end.
The canopy 10 has a horizontal top wall 12, integral inclined front and rear walls 13 and 14 and has end caps 15 at each end in secured relation.
An interior end frame 20 is provided having a front inclined wall portion 21 for secured engagement with the front wall 13, a horizontal top portion 22 and a rear inclined wall portion 23 for secured engagement with the rear wall 14.
The frame plate 20 has a dished portion 24 with a hub 25 and leg engaging and retaining lug portions 26.
An interior end frame 30 is provided having a front inclined wall portion 31 for secured engagement with the front wall 13, a horizontal top portion 32, and a rear inclined wall portion 33 for secured engagement with the rear wall 14.
The frame plate 30 has a dished portion 34 with a hub 35 and leg engaging and retaining lug portions 36.
A crank shaft 37 extends through and is supported in the hubs 25 and 35, extends through the end cap 15 at one end and has an exteriorly accessible manually operable crank arm 38.
The shaft 37 has an oscillatable inverted U-shaped carriage or cradle frame 40 supported thereon with end walls 41 and 42 and hubs 43 and 44 for bearing engagement with the shaft 37. The cradle frame 40 has a bottom closure wall portion 45 and front and rear wall portions 46 and 47, the cradle frame 40 preferably being constructed to prevent access thereabove which might result in pinching of fingers.
The front and rear wall portions 46 and 47 have openings 48 for attachment of the supporting rods (not shown) of a swing seat or a cradle.
The hub 43, at one end, extends into an opening 50 at one side of a ratchet wheel 52, the ratchet wheel 52 being carried on the crank shaft 37. The ratchet wheel 52 has a collar 53 on which one end of a tubular shaft 55 is secured. The shaft 55 preferably has a struck-in tongue 56 engaged in a slot 57 in the collar 53 to key the shaft 55 to the ratchet wheel 52.
The other end of the shaft 55 has a bushing 59 secured therein with a central opening 60 through which the crank shaft 37 extends. The bushing 59 has a radial slot 61 which is engaged by a struck-out tongue 62 for rotation of the shaft 55 upon rotation of the crank shaft 37.
The carriage 40 has spaced pivots 64 and 65 which pivotally support a pawl 66 having an edge portion 67 for engagement with one of the teeth on the outer periphery 68 of the ratchet wheel 52, and which is adapted to be moved outwardly upon movement of the ratchet wheel 52 in a clockwise direction as seen in FIG. 2.
The interior end frame 20 has a bracket 70 with a pivot opening 71, which with a parallel portion of the end frame 20 provides supports for pivots 73 and 74 of a safety dog 75. The dog 75 has a tongue 76 for engagement with a tooth of the outer periphery 68 of the ratchet wheel and a control tongue 78 for engagement by the inner cylindrical toother surface 79 upon faster than normal movement of the ratchet wheel 52 to cause the tongue 76 to engage.
A spring 81 is engaged at one end on an arm 82 on the safety dog 75 and engaged at its other end on an arm 83 on the pawl 66. The spring 81 acts in tension and in compression. The operation of the pawl 66 and safety dog 75 is similar to that described in U.S. Pat. No. 3,071,339.
In order to provide the desired impelling force for long continued operation the force spring system to be described is employed.
An inner coil spring 85 preferably of spring wire of square or rectangular cross section to reduce the tendency of the turns to override, has one end hooked as at 86 into an opening 87 in the shaft 55, has a plurality of turns as at 88 in close engagement with the shaft 55 to provide more secure fastening action, a plurality of turns as at 89 of conical configuration, and the major portion of its length with helical turns of substantially uniform diameter as at 90. The inner spring 85 has an inwardly extending hook 91.
A spring section connector or coupling 95 is provided having a mounting sleeve 96 freely rotatable and longitudinally slidable on the tubular shaft 55.
The coupling 95 has a radially outwardly disposed segment 92 with an end shoulder 93 for engagement by the hook 91, and outwardly extending spring retention fingers 94 and 97 for spring retention on the segment 92. A spring retention arm 99 is provided having a face 100 in a common plane with a face of the retention finger 97 and has a projection 101. A spring retention arm 102 is provided having a face 103 in a common plane with the face 100 and has a spring holding projection 104. The coplanar faces 100 and 103 serve as abutments to retain the inner spring 85 on the coupling 95.
An outer spring 105 is provided, preferably of spring wire of square or rectangular cross section, and has an outwardly extending hook 106 for engagement with the projection 101.
The coplanar faces 100 and 103 of the spring retention arms 99 and 102 and the corresponding face of the retention finger 97 also serve as abutments to retain the outer spring 105 on the coupling 95.
The projection 104 limits outward displacement of the outer spring 105.
An additional abutment arm 114 on the coupling 95 retains the ends of the springs 85 and 105 against displacement beyond the coupling 95. The spring 105 has its major portion of helical turns as at 109 and at the end opposite the hook 106 has a plurality of conical turns as at 110, and a plurality of turns as at 111 for engagement with the shaft 55, when the shaft 55 is wound, and an end hook 112 which is engaged in the end wall 42 of the carriage 40. The spring 105 is of opposite hand from the spring 85.
The smaller diameter turns 111 of the outer spring 105 serve as release turns and provide a slip-clutch action to prevent excessive pull on the hook portion 112 upon movement of the carriage 40 as well as upon winding.
The mode of operation will now be pointed out.
The power springs 85 and 105 are wound by turning the crank arm 38 and the shaft 55, turning of the tubular shaft being effective for winding the inner spring 85 and through the coupling 95 also winding the outer spring 105. The effect is like that of winding a long continuous spring. Winding of the springs 85 and 105 causes the coupling 95 to move along the shaft 55 toward the ratchet wheel 52, the coupling 95 turning on the shaft 55 as required for winding and transferring a winding action from the inner spring 85 to the outer spring 105.
The springs 85 and 105 are together effective for imparting a turning force to the shaft 55. A swinging movement of the carriage 40 is effected by reason of the escapement provided by the pawl 66 and safety dog 75.
The springs 85 and 105 are self-locking on the spring section coupling 95.
The extended effective length of spring made available by the coupiing of the inner and outer springs 85 and 105 provides for a greatly extended period of operation for a single winding operation and which can be of the order of one hour, dependent upon the cross-sectional area of the spring turns and the number of turns.