BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a mechanical mermaid having a tail movement mechanism according to an illustrative embodiment of the present invention.
FIG. 2 is a perspective view of the coupling mechanism between a motor and the curling mechanism according to the embodiment.
FIG. 3 is a top plan view of the mermaid's tail, showing the jointed segments of the tail uniformly curling in the counterclockwise direction.
FIG. 4 is a top plan view of the mermaid's tail, showing the jointed segments of the tail uniformly curling in the clockwise direction.
FIG. 5 is an exploded view of two of the jointed segments of the mermaid's tail and the control links that connect non-adjacent segments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a mechanical, battery operated swimming mermaid bath or swimming pool toy constructed according to one illustrative embodiment of the present invention. Mermaid 10 includes a torso 20, a first rotating jointed segment 50, a second segment 60, and a distal most and third segment 70. A flexible elastomeric tail and skin, shown in outline, are fitted over the curling tail mechanism structure. Torso section 20 has housed within it one or more batteries (not shown) for providing power, a motor (not shown), and a reduction gear set (not shown). The battery and motor are contained within a watertight housing, which may include the reduction gear set as well. The components not shown are standard design components, and persons skilled within the relevant art will be able to select and/or design the necessary components.
FIG. 2 shows the distal end of torso section 20 with its cover removed to reveal the mechanical interface between the drive shaft and the tail curling structure. Drive shaft 22 protrudes from the reduction gear housing. Attached to drive shaft 22 is a rotating wheel 24 having a cylindrical knob 26. Knob 26 fits into a slot 33 formed in the proximal end 32 of first segment 50, which is attached to the distal end of first segment 50 via lever 34. Lever 34 is rotatably mounted to torso 20 by round pin 36. First cross member or control link 45 has an approximate 90 degree bend at its proximal end, which is rotatably attached to the torso by the bent end being fitted into a hole within control link support 38. As drive shaft 22 and wheel 24 rotate, knob 26 travels in circles, causing end 32 to rock up and down in an oscillating sinusoidal manner. This causes the distal end of first segment 50 to also rock up and down in the same manner as first segment 50 pivots on pin 36, which provides the axis of rotation for first segment 50.
FIG. 3 is a top plan view of the tail mechanism with the covers (not shown) of the torso 20, first segment 50, and second segment 60 removed, and with the structure curled upward in a counterclockwise curling motion. In the illustrative embodiment the covers of segments 50 and 60 are attached to the segments and held in place thereto via threaded screws (not shown) which screw into the center holes of cylindrical shafts 54 and 64.
FIG. 5 is an exploded view that shows the details of the individual segments, and shows the way that the control links are mounted to the segments. Second segment 60 includes a pivot section 63 which receives cylindrical pivot pin 54 of first segment 50, a cylindrical pivot pin 64 received in hole 76 of third segment 70, and a lever portion 61 which has a hole 66 for receiving the bent distal end of first control link 45. As control link 45 pushes or pulls on lever portion 61, second segment 60 rotates downward or upward, respectively, relative to first segment 50 about cylindrical shaft 54. The proximal end of first control link 45 is fitted into control link support 38 attached to torso 20 (FIG. 1).
Second control link 55 has two ends bent at approximately 90 degrees for rotatably fitting into hole 57 in first segment 50, and into hole 76 in lever section 71 of third segment 70. Note that the control link therefore rotatably connects first segment 50 and non-adjacent third segment 70, but is not connected to second segment 60 across which it generally extends. A line between the two mounting points 57 and 76 defines a longitudinal axis of second control link 55. Similarly, first control link 45 has a longitudinal axis defined by the two points at which the control link is mounted.
Returning to FIG. 3, pin 36 defines a rotational axis of first segment 50. Similarly, cylindrical shafts 54 and 64 define the rotational axes of second and third segments 60 and 70, respectively. An imaginary line passing through the segments' axes of rotation defines a longitudinal axis of the tail. When the tail is straight, there is a single longitudinal axis passing through all of those pivot points.
In the figure as shown, slotted proximal end 32 (not shown) of first segment 50 is rotated toward the bottom of the figure, which has caused the distal end 52 of first segment 50 to rotate upwards about pin 36. First control link 45 is attached to torso 20 at support 38 and is attached to second segment 60 at hole 66. Because first control link 45 is connected skew to the longitudinal axis of the pivot points which link the segments together, the upward rotation of first segment 50 has caused first control link 45 to pull backwards on lever portion 61 of second segment 60, which caused second segment 60 to rotate upwards and counterclockwise relative to first segment 50. That is, second segment 60 acted upon by control link 45, has rotated in the same direction with respect to the first segment as the first segment rotated with respect to torso 20. Similarly, because second segment 60 has rotated upward relative to first segment 50, second control link 55, which is connected between first segment 50 at hole 57 and third segment 70 at hole 76 within lever section 71, has caused third segment 70 to rotate upward or counterclockwise with respect to second segment 60. The end result is that a movement of slotted end 32 has caused a ripple effect by which each segment within the mechanism has curled in turn in a single direction to impart a uniform curl throughout the mechanism.
FIG. 4 shows the mechanism curling uniformly downward and clockwise. In this figure, slotted end 32 (not shown) has been driven toward the top of the figure, which caused first segment 50 to rotate downward. This has caused first control link 45 to push on lever section 61 of second segment 60, which in turn rotated second segment 60 downward, which in turn caused third segment 70 to rotate downwards in response to a push on it from third control link 55.
The mechanism of the present invention has therefore caused a simple, oscillatory up-and-down or side-to-side movement at slotted end 32 to be translated into a uniform curl of the entire tail, first in one direction and then in the opposite direction, thus causing the mechanism to simulate the flopping back and forth motion of a fish tail and inducing a swimming action of the mermaid.
In the illustrative embodiment, the distal end of first control link 45 is mounted generally above the pivot point of the second segment, and the proximal end of second control link 55 is mounted generally below that same pivot point, such that when the curling mechanism is straight, a line drawn between the first control link's distal mounting point and the second control link's proximal mounting point defines a line that is generally perpendicular to the longitudinal axis of the curling mechanism and crossing through the pivot axis between two adjacent segments. Those structural details are not necessary to the practice of the invention, although arranging the control links to cross over the longitudinal axis of the mechanism and to be mounted at such points does produce a compact, simple, and efficient design for this particular application.
In an alternative embodiment, instead of the first segment being oscillated up and down to initiate the curling motion, the first control link could be pushed and pulled by action of the motor, thus initiating the rotation of one jointed segment relative to another. Although it is presently contemplated that a motor interface that causes the first segment to rock up and down in order to initiate curling action will generally be a simpler and thus preferred mechanism than one that pushes and pulls on a control link, there may be applications in which pushing and pulling on a first link may be preferred for various design reasons. Similarly, there are other ways to initiate a bending at the first segment, and the present invention contemplates use of such alternative mechanisms.
In FIGS. 3-5, second control link 55 is mounted to first segment 50 and to third segment 70 such that as second segment 60 is rotated counterclockwise relative to first segment 50, control link 55 pulls on lever portion 71 of third segment 70 to also cause it to rotate counterclockwise relative to second segment 60. That is, curling in a particular direction is propagated to successive segments. Instead of this arrangement, however, control link 55 could be mounted at different points on first segment 50 and on third segment 70 so as to cause a clockwise rotation of third segment 70 in response to a counterclockwise rotation of second segment 60. In such an arrangement, the action of the control links would make successive segments curl in the opposite direction. The result would be that the structure resists curling, rather than propagating curling, in response to angular displacement of any particular segment.
It will be appreciated that the term “present invention” as used herein should not be construed to mean that only a single invention having a single essential element or group of elements is presented. Similarly, it will also be appreciated that the term “present invention” encompasses a number of separate innovations which can each be considered separate inventions. Although the present invention has thus been described in detail with regard to the preferred embodiments and drawings thereof, it should be apparent to those skilled in the art that various adaptations and modifications of the present invention may be accomplished without departing from the spirit and the scope of the invention. Accordingly, it is to be understood that the detailed description and the accompanying drawings as set forth hereinabove are not intended to limit the breadth of the present invention, which should be inferred only from the following claims and their appropriately construed legal equivalents.
Patent Application
20070254556
