Patent Publication Number: US-6210249-B1

Title: Mechanical model of an animal

Description:
The invention relates to mechanical animal-modeling as defined in the preamble of claim  1 . 
     Mechanical animal models and in particular mechanical dogs are known of which the fore legs and hind legs are mobile in such manner that the mechanical dog can move forward. 
     An electromechanically driven motional and walking mechanism is known from the German Patent document A1 43 33 866 as the basis for the manufacture of walking human and animal models. In this quasi robotic design, a hip and shoulder joint with its three degrees of freedom has modeled using several servomotors in series. However this apparatus incurs the drawback of being mechanically complex and costly. Moreover the implementation of forward motion by simulating the hip joint almost naturally requires dynamic equilibrium with corresponding difficult and computer-intensive control of the servomotors of all legs to prevent the animal model from falling down. 
     An electromechanically driven motional and walking mechanism is known from the German patent document A1 43 33 866 as the basis for the manufacture of walking human and animal models. In this quasi robotic design, a hip and shoulder joint with its three degrees of freedom has been modeled using several servomotors in series. However this apparatus incurs the drawback of being mechanically complex and costly. 
     Because of the feature of the invention that the first and second drive mechanism are rigidly configured relative to each other in a torso of the animal model, there is the advantage that the actions carried out by real animals, for instance dogs, can be simulated or played back in corresponding manner by the mechanical animal model. In especially advantageous manner, two mutually offset axes of rotation at one hind leg can simulate the leg-raising and corresponding relieving of the animal. Such relieving is carried out by a dog for instance to scent its territory. Moreover the apparatus of the invention advantageously offers an especially simple mechanical design with corresponding simplified selective mechanism control for a forward motion of the animal model with static equilibrium or to simulate a relieving action by the animal model with corresponding “leg-raising” without tipping over the animal model. Corresponding simplified selective mechanism control for a forward motion of the animal model with static equilibrium or to simulate a relieving action by the animal model with corresponding “leg-raising” without tipping over the animal model. 
     The function “dog relieving i.e., urination” can be especially realistically imitated in that the angle between the two axes of rotation be 90°. As a result the particular hind leg will be substantially raised laterally. 
     A mechanically and operationally reliable movement of the hind leg with two pivots is achieved in that the second drive mechanism drives a disk with a first cam slot. This cam slot is engaged by a first cam pin of a compensating lever supported at a pivot point and fitted with a second cam slot engaged by a second cam pin of a lever linking the at least one hind leg to its second picot, so that, when the disk is being rotated, the lever moves the hind leg to-and-fro about the second pivot by an angle predetermined by the first cam slot. 
     A second drive shaft is provided in the gearing unit of the first drive mechanism to provide other functions of the mechanical animal model, an actuator being affixed to said shaft which by means of head lever actuates a rotatable lower jaw, a movable tongue and/or a bellows at a head part. 
     Appropriately this drive means is a rotary disk with at least one salient cooperating with an end of the head part. 
     To selectively actuate the first or second drive mechanism of the first gearing unit, the latter comprises at least one shaft, displaceable into at least a first and second position, fitted with at least one gear, or a shaft with at least one gear displaceable into a first or second position, the particular gear transmitting in the first position a drive force to the first drive shaft and in the second position a drive force to the second drive shaft. For this purpose the shaft or the gear will be appropriately be spring-biased and be axially displaceable against the spring force. 
     In order to pass from actuation through the first drive mechanism to actuation through the second drive mechanism at accurately predetermined positions of the fore and hind legs, preferably a first switch is employed which automatically activates the second drive mechanism when commanded by an operator and deactivates the first drive mechanism. 
     To assure that the mechanical model shall remain stably erect on three legs—so that this model shall not fall down when the fourth leg is lifted—the first switch is positioned in such manner that it can be automatically actuated in a position of the fore legs wherein the fore leg diagonally opposite the hind leg to be actuated is vertically closer to the ground than the other fore leg and the other hind leg. 
     A second switch is preferably provided for a correspondingly defined switching reversal from the second to the first drive mechanism in order to deactivate the second drive mechanism as commanded by an operator and to activate the first drive mechanism. 
     Appropriately an operating system fitted with selection means controlled by an operator is provided to transmit to the first and to the second switch a command to actuate the first or the second drive mechanism. Illustratively the operating system wires the selection means to the switches. Preferably the selection means is three position switch, a first position deactivating the mechanical animal model, a second position transmitting a command to actuate the first drive mechanism and a third position a command to actuate the second drive mechanism. Preferably the operating system includes a power source to power the first and the second drive mechanism. In especially preferred manner, the power source is at least one battery and the operating system shall connect the power source by electrical lines to the switches and the drive mechanisms. 
     For life-like movements of the fore legs, these are eccentrically linked at the first pivot of the first gearing unit to a first drive shaft and they are also supported in rotatable manner at a third pivot distant from the first and are displaceable in the direction of a longitudinal axis of the fore legs. 
     To achieve a corresponding synchronized motion between the hind legs and the fore legs when moving forward, preferably a first lever is mounted in each case at the first eccentric pivot of each fore leg, the other end of this first lever in each case being connected to a second lever mounted at the first pivot of a particular hind leg. 
     To easily mechanically control the optimal actuation time of the second drive mechanism, a drive means for a first switch is provided in such manner at one of the first levers that the drive means can control the switch when the fore leg which is diagonally opposite the hind leg with the second pivot is vertically closer to the ground relative to the first drive shaft than the other fore leg and the other hind leg. 
     To imitate in a most life-like manner the function of the dog or animal relieving itself, a liquid container and a liquid hose from the container to the rear of the animal model are employed, a pump selectively driven by the second drive mechanism moving the liquid from the container to the rear. The liquid is discharged from an end of the liquid hose. Appropriately a second gearing unit having a shaft axially displaceable into a first position and a second position and fitted with at least one gear or a shaft having at least one gear displaceable axially into a first and second position is provided in the second drive mechanism to selectively control the raising of the hind leg or the liquid pump, the particular gear in the first position transmitting a drive force on a plunger of the liquid pump. The shaft or the gear are appropriately spring biased and are axially displaceable against the spring force. 
    
    
     The invention is elucidated below in relation to the drawing. 
     FIG. 1 is a longitudinal section of the mechanical dog of the invention, 
     FIG. 2 is a partly sectional topview, 
     FIG. 3 is a sideview of a first drive mechanism, 
     FIG. 4 is a section along line I—I of FIG. 3, and 
     FIG. 5 is a section along line II—II of FIG. 3, 
     FIG. 6 is a sectional sideview of a second drive mechanism fitted with a water spray, 
     FIGS. 7 a - 7   l  show schematically a cam pin guidance system for the dog&#39;s hind leg. 
     FIG. 8 is a rear view of the second drive mechanism of FIG. 6, and 
     FIG. 9 is a sectional topview. 
    
    
     The mechanical dog shown in FIGS. 1 and 2 comprises, in and at a housing, namely a torso  32 , a first drive mechanism  18 , a second drive mechanism  30 , fore legs  10  and  11 , hind legs  12  and  13 , a head segment  62  and a water system with a liquid container  88 , a liquid hose  90 , a liquid pump  94  with plunger  102  and a discharge aperture  134 . 
     The drive means of a first drive mechanism  18  is an electric motor  24  which through a gearing unit elucidated below in relation to FIGS. 4 and 5 selectively drives the forelegs  11  or an actuator  54 . The fore legs  11  in this process are driven by a first drive shaft  22  (FIG. 2) and an eccentric pivot  78  and furthermore are supported in pivotable manner at a third pivot  76  and in displaceable manner along the shaft of the fore leg  11 . When the motor  24  drives the fore leg  11  through the first drive unit  18 , this fore leg will be alternatingly raised and lowered on account of the eccentric pivot  78 . The corresponding opposite fore leg  10  (FIG. 2) is correspondingly but oppositely raised and lowered. Additionally there is a forward and backward movement of the fore legs  10  and  11  on account of the simultaneous support and guidance at the third pivot  76 . In this manner the mechanical dog is endowed with a walk-like mechanical advancing movement. 
     The drive mechanism  18  also drives the actuator  54 . In this process the motor  24  drives by means of the first drive mechanism  18  either the actuator  54  or the fore legs  11 ,  10 . In the shown embodiment, the actuator  54  is a disk with salients  64  that upon rotation of the disk  54  sequentially cooperate with an end  66  of the head lever  56 . This head lever  56  swings about a pivot and at the same time actuates a mechanical tongue  58  and a bellows  60 . First the bellows  60  is compressed and then it is released impulsively when a salient  64  disengages from the end  66  of the head lever  56  on account of the rotation of the disk  54 . Simultaneously air is pulled through a noise maker  108  and a tube  110  so that the mechanical dog gives off a corresponding noise or a sound predetermined by the noise maker  108  at the same time it moves its tongue. Preferably the noise maker  108  simulates barking. 
     Furthermore the first drive mechanism  18  includes a gearing unit  20  with shafts  106 , this gearing unit  20  being elucidated below in relation to FIGS. 4 and 5. 
     The fore legs  10  and  11  are connected by a lever  80  to the corresponding hind legs  12  and  13  behind them. One side of the lever  80  acts on the eccentric pivot  78  of one fore leg  11  and the corresponding other end  82  of the lever  80  cooperates through a linkage point  112  with a lever  84  linking the corresponding hind leg  13  by means of this pivot  14 . When the eccentric drive  78  moves the fore legs  11 ,  10  therefore, the lever  80  pivots the corresponding hind legs  12 ,  13  at the same time as the fore legs  10 ,  11 , but in the opposite directions, about the pivot  14 . 
     Moreover, as shown by FIGS. 1 and 2, the mechanical dog comprises at its rear a second drive mechanism  30 . This second drive mechanism  30  selectively actuates either the liquid pump  94  or, by means of a disk  38  fitted with a gearing unit not visible in FIGS. 1 and 2, the hind leg  13 . In addition to the pivot  14 , the hind leg  13  is supported on a pivot  26  to be pivotable about an axis of rotation  28 . As shown in particular in FIG. 2, the axes of rotation  16  and  28  of the pivots  14  and  26  of the hind leg  13  are substantially perpendicular to each other. As a result, when the mechanical dog carries out its normal walk, the hind leg  13  swings to-and-fro about the pivot  14  by means of the linkage of the lever  80 . Additionally, however, the hind leg  13  may be swung about the axis of rotation  28  laterally away from the mechanical dog by the second drive mechanism  30  acting through the disk  38 . Preferably this pivoting motion shall take place when the remaining legs  10 ,  11 , and  12  are still, that is when the mechanical dog is not driven forward. This “leg raising” simulates the behavior of a real dog illustratively relieving itself at a tree trunk. This typical dog behavior to scent their territory therefore can be simulated or copied in this operation of the mechanical dog. If the hind leg  13  is correspondingly raised about the axis of rotation  28 , the second drive mechanism  30  will actuate the plunger  102  of the liquid pump  94  and will move liquid out of the container  88  through the liquid hose  90  to an outlet or a discharge  134  of the hose  90  at the rear  92  of the mechanical dog. The liquid issues from the discharge  134  and the mechanical dog displays the life-like behavior of a dog relieving itself. 
     The forward motion generated by the first drive mechanism  18  and the dog&#39;s relieving operation powered by the second drive mechanism  30  will be carried out selectively, that is either the drive mechanism  18  or the drive mechanism  30  will be actuated. 
     The desired operation of forward motion or of relieving can be controlled by an operator using an operating means by appropriately using a selection means. If the mechanical dog is in the “forward motion” mode and the operation “relieving” were initiated immediately when the operator switches the control means, the fore legs  10 ,  11  and the rear leg  12  on occasion might be in such an adverse position that the mechanical dog would fall down upon raising the hind leg  13 . To prevent such a possibility, the “relieving” mode is initiated only for a given configuration of the legs  10 ,  11  and  12 . The optimal leg position is such that the fore leg  10  diagonally opposite the raising hind leg  13  subtends a horizontally smaller distance between the drive shaft  22  and the ground than the remaining legs  11  and  12 . In this configuration the mechanical dog rests in a stable three-legged position. 
     The “relieving” operation in the stable three-leg configuration of the embodiment is shown in FIG. 2 is implemented by a switch  74  actuated by a control means  86  at the lever  80  between the fore leg  10  and the hind leg  12 . As shown by FIG. 2, the switch  74  will be actuated by the control means  86  only when the lever  80  and hence the fore leg  10  are in their farthest forward position, while simultaneously the legs  11  and  12  are pivoted into a rear position. These legs  11  and  12  thereby are farther away from the ground relative to the drive shaft  22  and the fore leg  10  and accordingly the mechanical dog shall rest on them. 
     When commanding the “relieving” mode during the forward-motion mode, the dog moves on a little yet until the corresponding position of the legs  10 ,  11  and  12  has been adjusted and the control means  86  actuates the switch  74 . This switch  74  then starts the second drive mechanism  30  while stopping the first drive mechanism  18 . In this process the operating system and the selection means at this operating system are connected in such manner with the drive mechanisms  18  and  30  and the switch  74  that switching reversal can take place only when commanded by the operator at the operation system by means of the selection means. So long as the case is otherwise, while the control means  86  does in fact constantly act on the switch  74  during forward motion, an appropriate electrical circuit nevertheless will prevent starting the second drive mechanism. 
     If inversely an operator commands again the forward-motion mode during the dog&#39;s relieving mode with raised hind leg  13 , the change from the drive mechanism  30  to the drive mechanism  18  will not be abrupt either, rather another switch, not further shown, will be actuated for a given position of the disk  38 . Preferably this position of the disk  38  is selected in such manner that the hind leg  13  shall be firmly on the ground to allow implementing the forward-mode of the mechanical dog without danger of its falling down. The delay in switching from the drive mechanism  30  to the drive mechanism  18  again is implemented by electrically wiring the operating system to the drive mechanisms  18 ,  30  and the corresponding switches. 
     As is further shown in FIGS. 1 and 2, the affixation of the hind legs  12  and  13  differ basically in relation to the additional function of the hind leg  13 . Whereas, as shown in FIG. 2, the hind leg  12  is screwed in place by a screw  114 , the hind leg  13  is associated with two axes of rotation  16  and  28 . To endow the hind leg  13  with a rotatable degree of freedom both about the axis  16  as well as about the axis  28 , the second lever  84  must be designed accordingly. This lever  84  encloses the pivot  14  like a horseshoe (FIG. 1) and forms the additional axis of rotation  28  at the end of the horseshoe. 
     The two drive mechanisms  18  and  30  are rigidly mounted in the housing  32 , that is they are mutually immobile. The second drive mechanism  30  illustratively is affixed by a screw  104  to a shell segment of the torso  32 . 
     The first drive mechanism  18  is elucidated below in relation to FIG.  3 . By means of a gearing unit not visible in FIG. 3, the motor  24  drives selectively either the first drive shaft  22  with pivot  14  or the second drive shaft  52 . The eccentric pivot  78  is a distance from the first drive shaft  22  and, as shown in FIG. 1, cooperates correspondingly with a fore leg  10 ,  11 . A disk-shaped actuator  54  with salients  64  is mounted to the second drive shaft  52 . As the disk  54  rotates, the salients  64  consecutively engage and end  66  of the lever  56  which they drive correspondingly. The head lever  56  drives the tongue  58  and a bellows not elucidated in FIG. 3. A head support  116  links the head part  62  not shown in FIG. 3 to the first drive mechanism  18 . 
     The first gearing unit  20  shown in FIGS. 4 and 5 comprises several gears  118  and corresponding shafts  119  and also the first drive shaft  22  (FIG. 5) and the second drive shaft  52  (FIG.  4 ). An axially displaceable gear  70  loaded by a spring  72  is mounted on a shaft  68 . FIGS. 4 and 5 show the upper or the lower position of the displaceable gear  70 . As shown by FIG. 4, in its upper position the gear  70  transmits a drive force to the second drive shaft  52 , thereby driving the actuator  54  and the lever  56  at its end  66 , thereby powering the tongue  58  and the bellows  60  (FIG.  1 ). If, on the other hand and as shown in FIG. 5, the axially displaceable gear  70  is displaced downward, it will transmit a drive force to the first drive shaft  22  and by means of pins at the eccentric pivots will drive correspondingly the fore legs  10  and  11  (FIGS. 1,  2 ) to implement a forward walk. Therefore the displacement of the gear  70  will alternatingly implement the dog&#39;s forward motion or its barking. Additional control of the electric motor  24  or even a change in angular speed or the like are not needed. 
     FIG. 6 shows the second drive mechanism  30  with the surrounding water system consisting of a liquid container  88 , liquid hose  90  and water pump  94  with plunger  102 . The second drive unit  30  further comprises a gearing unit  34  not elucidated in FIG.  6 . This gearing unit  34  is discussed further below in relation to FIG.  5 . 
     The second drive mechanism  30  also comprises a disk  38  which by means of a gearing unit not visible in FIG. 6, further by means of a cam pin  42  of a compensating lever  44  and a second cam pin  49  at a lever  50  implements the lateral pivoting of the hind leg  13  about the axis of rotation  28 . FIG. 6 merely outlines the hind leg  13  and detailed discussion is excluded. 
     The action of laterally pivoting the hind leg  13  by the disk  38  is shown in FIGS. 7 a  through  7   l  by twelve different positions of the disk  38 . In this respect the disk  38  is fitted with a cam slot  40  engaged by a first cam pin  42  of a compensating lever  44 . The compensating lever  44  is rotatably supported at a pivot  46 . Moreover the lever  44  is fitted with a second cam slot  48  engaged by a cam pin  49  of another lever  50 . In turn this lever  50  acts on the additional pivot  26  of the hind leg  13  to control this hind leg  13 , that is, rotation of the lever  50  entails pivoting the hind leg  13  at the pivot  26  about the axis of rotation  28 . In FIGS. 7 a  through  7   l,  the axis of rotation  28  at the pivot  26  is perpendicular to the plane of the drawing. The hind leg  13  is not shown pictorially for sake of clarity in showing the dog&#39;s motion. 
     When the disk  38  is rotated, the gearing unit  50  through the first cam pin  42  forces the compensating lever  44  to move up from the initial position  1  in FIG. 7 a  to the position  6  in FIG. 7 f.  This motion constrains a corresponding rotation by means of the cam pin  49  to the lever  50  to implement pivoting the hind leg  13  sideways. In position  6  of FIG. 7 f,  the hind leg  13  at last has been fully pivoted and the cam slot  40  has been designed in such manner that at constant, continued rotation of the disk  38 , the pivoted hind leg  13  shall remain a predetermined time in its swung-out position. As the disk  38  continues to rotate, the course of the cam pin  42  in the cam slot  40  implements swinging back the hind leg  13 . This sequence is shown in detail by positions  7  through  12  in FIGS. 7 g  through  7   l.  The compensating lever  44  pivots downward about its pivot  46  and correspondingly rotates the lever  50 . In position  12  of FIG. 7 l,  the hind leg  13  has been fully retracted. In this position, if commanded by an operator, forward motion would be resumed by the disk  38  by actuating an omitted switch OFF the second drive mechanism  30  and to switch ON again the first drive mechanism  18 , reinstating the operation of forward motion alternating with barking. 
     The second drive mechanism  30  actuates selectively not only the disk  38  swinging out the hind leg  13 , but also the water pump  94 . FIG. 8 is a rear view of the second drive mechanism  30  showing part of the water supply. The plunger  102  of the liquid pump  94  is driven by a rotary disk  126  and an eccentric pivot  128 . The rotation of the disk  126  is converted into a reciprocating motion of the plunger  102 . The lower end of the plunger  102  is eccentrically connected through a shim disk  132  with the rotating disk  126 . 
     The water supply further comprises an air valve  122  fitted with a spring  124 . A water valve  130  is also mounted in the water system. 
     FIG. 9 elucidates the selective control of the water pump  94  or of the disk  38 . It shows the second gearing unit  34 . By means of various gears and shafts, a motor  36  drives a gear  98  on a shaft  96 . The gear  98  is axially displaceable along the shaft  96  and is spring-loaded by a spring  100 . When the gear  98  is axially displaced, it meshes with various gears and in this manner the force exerted by the electric motor  36  is transmitted either to a drive shaft of the rotating disk  126  or to a drive shaft of the disk  38 .