Abstract:
The invention is related to a swimming teaching apparatus which provides user to make a complete swimming like action on land. The special technical features are a body rotation mechanism, arms guide, a breathing sink and a kick pad for legs, all together to perform on land swimming exercise. All strokes can be skilled with a precise instruction by the coach when the user is stationary on the invention. The invention allows user to do continuous practice of the swimming movements without be interrupted by a breathing problem, when the arms and legs are well coordinated, breathing sink then add to exercise, user can do combined actions slowly to ensure the correctness. The invention is tried to substitute the buoyancy of water as a pre-training machine for those schools which have no swimming pools can still carry out swimming courses for their students to reduce drowning incidents.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a machine that emulates strokes which including breathing exercises. The invention is to provide a platform for practice all strokes to familiarize students with the swimming skills. 
         [0003]    2. Description of the Prior Art 
         [0004]    All of the swimming lessons of schools are held in the swimming pools, for those schools which have no swimming pools, swimming courses must be held in another swimming pool outside their school, this is very inconvenient. In order to solve the problems of non-swimming pool schools, a swim simulator is invented. 
         [0005]    Take freestyle for example, the arms should pass the underside of the lying body along the body center line from the front head to the back thigh, the body has to rotate to match the rhythm of breathing and arm cycles which includes palm enter, stretch, catch, pull, recovery to the front. In order to completely simulate the freestyle movements on land, the body needs to be supported from head to feet entirely, meanwhile, a space under the body must be reserved for arms to move, and also a body rotation mechanism is need for linking arm cycle and breathing. 
         [0006]    A swimming simulator should allow the user to lie down on it comfortably just like floating on water, and let user learn swimming techniques on land like swimming in water. 
         [0007]    How to do it? 
         [0008]    My personal view is to have the following requirements.
   1. It should have an adequate length of backward tilt board to support the whole lying body from head to tiptoes. (like buoyancy of water which support the whole body on water). The backward tilt board is to simulate the body is in an inclined downward position when swimming in water   2. It should have an arm and hand guide part. (to give user a precise route to familiar with the arm movement)   3. A body rotation part is necessary for freestyle and backstroke. (to simulate the body rotation movement of freestyle and backstroke and to facilitate breathing of freestyle)   4. It should have a space below the tilt board for arms to move just like swimming.   5. It should have a suitable pad for feet kicking. (for support the legs and feet do the similar motion as in swimming)   6. It should have a breathing part (to familiar with the complete swimming technique on land instead of go in water)
       The rhythm of swimming is the first things to be considered in develop the invention, in other words, familiar with swimming technique is more important than increase swimming muscle strength for beginners. User should practice arms and legs move in sequence without disorder.   
       
 
         [0016]    According to the requirements of item 1, with adequate length of bench board to support the lie down body length is the basic elements of the invention, the user can practice swimming rhythm just as if the body floating in the water. The prior inventions which are missing or short of board to support the foot, user cannot kick freely with the straight foot and use the instep to kick on a surface; the hands and feet coordination cannot be done, either. This would include devices such as disclosed in U.S. Pat. No. 7,291,049 (James H. Davis), U.S. Pat. No. 6,790,164 (James Davis), U.S. Pat. No. 6,790,163 (Keith Van De Laarschot), U.S. Pat. No. 6,142,912 (John Profaci), U.S. Pat. No. 5,158,513 (Michael P. Reeves). 
         [0017]    According to the requirements of item 2, the swimming arm cycle which includes open palm entry, open palm stretch, open palm catch, open palm pull and push, exiting the stroke with palm muscle relaxed with high elbow recovery. So the palms are always open during the arm cycle. Many of the prior inventions let hands grab handles, arm cranks or levers without open palms to practice swimming, because the muscles used for the palm grip and the palm open are different, it means grip something with a palm is not the same palm posture as swimming. This would include devices such as are disclosed in U.S. Pat. No. 7,585,256 (David Day Harbaugh, IV), U.S. Pat. No. 7,104,931 (Robert Marc Saul), U.S. Pat. No. 6,790,163 (Keith Van De Laarschot), U.S. Pat. No. 6,764,432 (Joseph B. Hippensteel), U.S. Pat. No. 6,764,431 (Mark Stuart Yoss), U.S. Pat. No. 5,158,513 (Michael P. Reeves), U.S. Pat. No. 4,422,463 (Harry C. Hopkins). U.S. Pat. No. 4,537,396 (Lindsay A. Hooper) have palms opened but tied on a flat paddle, however it still can&#39;t totally release their muscles for simulate recovery movement due to a string force kept doing on the arms, but the U.S. Pat. No. 4,537,396 (Lindsay A. Hooper) license date in 1985 Aug. 27 shows an important idea that by placing a paddle on a string handle is a better way to simulate the open palm condition of swimming. Another U.S. Pat. No. 5,354,251 (Robert H. Sleamaker) license date in 1994 Oct. 11 also shows the same usage of a paddle fastened on a string for swimming practice. 
         [0018]    U.S. Pat. No. 5,391,129 (Viatcheslav K. Zaitsev) shows a pair of fixed traction elements which are curved surfaces from the side view, the arms are stretched without bend when move along the curved traction elements, It is very laborious if swim this way because the stretched arm produce bigger torque to the arms. 
         [0019]    The U.S. Pat. No. 6,142,912 (John Profaci) license date in 2000 Nov. 7 shows a paddle assembly is installed on a hand track, the hand tracks is summarized as follows:
   1. Hand track system includes a pair of hand tracks positioned on opposing sides of the table.   2. Hand track is contoured of a preset, yet adjustable path that replicates an “S-shaped” path below the body.   3. The paddles will rotate around the rails when move to the back.   4. Each hand track is comprised of a plurality of track sections. As we know from above mentioned U.S. Pat. No. 4,537,396 (Lindsay A. Hooper) license date in 1985 Aug. 27 and U.S. Pat. No. 5,354,251 (Robert H. Sleamaker) license date in 1994 Oct. 11 that the paddle had been used for swim simulator since then.   
 
         [0024]    Today, however, swimmers use straight line arm stroke rather than the contoured, S-shaped” path stroke as can be seen in all swimming race and instructional videos, the reason is that the body and the arms should be looked as a whole, the contoured, S-shaped” path stroke is not a streamlined body shape because the lead arm stretch to the front but expand outwards will cause forward resistance and reduce the pushing effect of the other hand. 
         [0025]    Another invention needs to be discussed is U.S. Pat. No. 6,409,634 (John Profaci), it has a straight hand track system and is summarized as follows:
   A. The hand track systems are joined by a cable.   B. The cable is received by a pair of pulleys coupled with forward portions of the enclosure, for directing the cable between the hand track systems.   C. The pulleys are coupled with the forward portions of the enclosure so that the cable is placed in an orientation which substantially parallels longitudinal axes defined by the hand track systems.   D. The hand grip which is sliding received by the rail for movement along the longitudinal axis of the rail and for rotation about the longitudinal axis of the rail.   
 
         [0030]    The item A are relation between cable and pulley, many of the prior art had already disclosed this knowledge, such as U.S. Pat. No. 2,716,027 (Fritz Henry Gehri) license date in 1955 Aug. 23, disclosed the same pulley-cable combination. U.S. Pat. No. 3,999,752 (Sam Kupperman) license date in 1976 Dec. 28 disclosed a pulley-cord with adjustable hand grips. U.S. Pat. No. 4,060,240 (Virgil M. Dunston) license date in 1977 Nov. 29, disclosed a design to adjust cord length of pulley-cord device. U.S. Pat. No. 4,948,119 (Richard T. Robertson, Jr) license date in 1990 Aug. 14, disclosed an independent resistance device (same as independent systems including return mechanism mention in U.S. Pat. No. 4,948,119) for simultaneous pulling movement use, so it is a well known knowledge of the usage of pulley and cable combination. 
         [0031]    The item B shows the rail and the pulley are Installed separately. 
         [0032]    The item C shows the pulleys installed in a higher position of the enclosure than the rails. 
         [0033]    The item D states the slide sleeves will rotate on the rail. 
         [0034]    The facts about the straight hand track of the U.S. Pat. No. 6,409,634 (John Profaci) is:
   1. The paddle assembly will roll when sliding along a rail.   2. The paddle assembly keeps not rotated by a guiding board of the enclosure.   3. The cable is possible to derail from the pulleys because the rails are horizontally but not vertically installed, even if the pulleys are installed a little bit higher than the rails, as when the horizontal forces made by the user disappear, the cable is in a relaxed condition, and the gravity is not able to help the horizontal cable remain on the grooves of the pulleys.   4. The tracks and the pulleys are firmly fixed on the enclosure and are not intend to adjust for different users.   
 
         [0039]    In order to satisfy our need, the rotatable hand grip will change to a not rotating paddle and further to solve the problem of derailment. 
         [0040]    According to the requirements of item 3, a good body rotation mechanism is the one which only rotates the body (as shown in  FIG. 7A ) but not moves the body (as shown in  FIG. 15 ). The prior body rotation inventions are divided into two categories:
   1. The inverted pendulum movement (which is not a rotation motion but a swing motion) (as shown in  FIG. 15 ):
       As long as there is a combination of a supporting board rotated by a shaft, no matter how the rotating shaft is under the supporting board or passes through the center of the supporting board, as the supporting board rotates around the shaft, the lying body on top of it is doing an inverted pendulum movement. It means the body center rotates around the rotating shaft but not itself, the body moves from left to right and from top to bottom. When the body tilts to one side form the highest middle point, the body center is below the highest middle point, it&#39;s laborious to against gravity and to make the body return to the highest middle point and then reach to the other side lower point, it takes strength to lift the center of gravity of the body for back and force swing. In actual experiment, once the body tilt to one side, many users failed to tilt the body back to the highest middle point, even if they did, it shows that the body and the head are in a continuous back and forth swing, this is not the expected motions we want as the fact that the head won&#39;t offset to the right or left when swim. If a sink is installed in front of it, the user&#39;s head will swing back and forth and cannot stay steady above the sink to practice breathing. The inverted pendulum movement is totally different from actual swimming body rotation and should not be adopted for an ideal body rotation mechanism. This would include devices such as disclosed in U.S. Pat. No. 7,601,103 (Her-Chun hen), U.S. Pat. No. 7,591,764 B2 (Brian Zuckerman), U.S. Pat. No. 6,790,164 (James Davis), U.S. Pat. No. 5,860,899 (William R. Rassman), U.S. Pat. No. 5,354,251 (Robert H. Sleamaker), U.S. Pat. No. 5,158,513 (Michael P. Reeves), U.S. Pat. No. 2,109,775 (Jesse B. Hudson).   
       2. The body rotation movement (as shown in  FIG. 7A ):
       U.S. Pat. No. 2,109,775 (Jesse B. Hudson) license date in 1938 Mar. 1 has shown an arc shaped body support was adopted in swimming machine, nevertheless, this invention with arc shaped body support didn&#39;t promise a true body rotation effect because its underside part is a shaft and the shaft will pivot the arc shaped body support, therefore swing the above body, this invention shows the arc shaped body support had been used but cannot ensure a pure body rotation movement (as shown in  FIG. 15B ).   U.S. Pat. No. 5,429,564 (Michael P. Doane), license date in 1995 Jul. 4, U.S. Pat. No. 5,628,632 (Michael P. Doane), license date in 1997 May 13, U.S. Pat. No. 6,142,912 (John Profaci) license date in 2000 Jan. 7 are three nice approaches to body rotation mechanisms. The U.S. Pat. No. 5,628,632 (Michael P. Doane) is modified from U.S. Pat. No. 5,429,564 (Michael P. Doane), this two can be regarded as one. So only two of the above three inventions left for discussion.   
       
 
         [0046]    The body rotation features of the U.S. Pat. No. 5,628,632 (Michael P. Doane) is: (for easy to watch, we redraw a perspective illustration of the invention as shown in  FIG. 16 )
   1. It is a rolling rotation movement.   2. The bottom of the torso support has two curved tracks (called the crescent shaped support pieces) rest upon two pairs of rollers.   3. The rollers are grooved such that the curved tracks sit in the grooves of them to prevent the torso support from any forward or rearward movement.   4. Use springs or resilient bands serve to fix the torso support down to the rollers. The spring or resilient bands also help to pull the body from rolled down position back to the neutral position.   
 
         [0051]    The body rotation features of the U.S. Pat. No. 6,142,912 (John Profaci) is:
   1. It is a sliding rotation movement.   2. The lower frame and the above tray are coupled by bearing structures.   3. The lower frame is a curved surface base which is a sliding part.   4. The underside of the tray has curved races to engage the curved tracks on the frame and a channel of the frame for receiving a stop of the tray.   5. For purposes of safety, an elastic band attached to and extending between the tray and stationary portions of the table, for stabilizing the tray relative to frame or to bias the tray toward a neutral (centered) position.   
 
         [0057]    The similarities between the above mentioned patents are:
   1. Both have either projected or recessed tracks to guide the rotation. One is curved races of upper torso support to grooves of rollers and the other is curved races of tray to engage the curved tracks of frame.   2. Both of their contact interfaces of rotation, by side view, are not at the ends of the torso support or the tray.   3. Both have elastic band or resilient bands to stabilize the upper torso support or tray.   
 
         [0061]    The reason why elastic band be used to secure the body rotation mechanism is because of the contact interfaces of rotation is in the middle section, the length of the two contact interface is shorter than the length of above torso support or tray, this is an unstable condition, when a force applied on the front edge or the rear edge of the torso support or the tray, a bending moment is formed to turn over the torso support or the tray, so the spring or resilient bands is to resist the bending moment. But the spring or resilient bands also limit the rotation effect of the torso support and the tray. We will abandon the use of the spring or resilient bands and be more stable by improved supporting structure. 
         [0062]    According to the requirements of item 4, the overall dimensions of the body rotation mechanism should be as compact as possible and should not be too big to obstruct the arm movement under the body along the body center line. 
         [0063]    The lower frame of the U.S. Pat. No. 6,142,912 (John Profaci) is a fixed rigid body, the dimensions of the lower frame won&#39;t change, when the above tray rotates from side to side, the lower frame is remain intact, the arm moves to the back will be restricted by the top edges of the lower frame, the arm is hardly to move along the body as we can see from the end elevation view that the unchanged lower frame stops the way. In fact this body rotation mechanism only provide a first half space for the arms, there is no enough room for arms pushing to the second half space under the body like swimming, forced the rails of the hand tracks be installed on the opposite sides of the table from its middle portion. 
         [0064]    The lower part of the U.S. Pat. No. 5,628,632 (Michael P. Doane) is a single beam, because strings are used for the arms movement, no arms guide tried to install under the body rotation mechanism. 
         [0065]    Another U.S. Pat. No. 7,291,049 (James H. Davis) has a different body rotation mechanism, but has the same problem that there is no space reserved for arms movement under the body. 
         [0066]    According to the requirements of item 5, a suitable pad for legs is the one which has more downward sloping than the inclined board. The reason is when we kick in the water, our legs start near the water level and finish under the water with some depth, the position of the underwater leg is more downward sloping than the body line, so we installed an inclined pad on the second half of the inclined board for legs to kick with the foot straight as in swimming. My point of view is let the pad provide a space for the legs to kick freely and support them when not kick, guide the legs with any modules is not necessary because user can control the legs doing a simple up and down motion and they will not deviate. In fact, with foot straight and use the instep to kick the pad surface is the key point to be noticed and can promise forward propulsion be produced when in swimming. 
         [0067]    The prior art about the lower body support are fall into the following categories:
   1. Feet are guided or bounded so leg kick by the instep cannot be performed. This would include devices such as U.S. Pat. No. 7,104,931 (Robert Marc Saul), U.S. Pat. No. 5,707,320 (Huei-Nan Yu), U.S. Pat. No. 5,376,060 (John J. Murray), U.S. Pat. No. 5,366,426 (James P. Glavin), U.S. Pat. No. 5,282,748 (Oscar L. Little), U.S. Pat. No. 5,158,513 (Michael P. Reeves), U.S. Pat. No. 4,830,363 (Robert J. Kennedy).   2. The whole support pad doesn&#39;t bend from the middle. They are flat surface to support the user from head to foot, be horizontal or tilted placed, but there is no bending downwards since the middle point of the support for legs to kick like swim. This would include devices such as U.S. Pat. No. 7,585,256 (David Day Harbaugh), U.S. Pat. No. 7,044,818 (Craig Askins), U.S. Pat. No. 6,790,163 (Keith Van De Laarschot), U.S. Pat. No. 6,409,634 (John Profaci),   
 
         [0070]    The U.S. Pat. No. 5,628,632 (Michael P. Doane) illustrates its font torso support is sloped upward from the horizontal hip support; this is contrary to my concept. If we observe the swim posture of freestyle under water, we can find the legs are kicking downward relative to the body which is in the level. 
         [0071]    According to the requirements of item 6, a breathing sink appeared for the first time could be added as a useful tool for a complete practice of swimming on land, allows user concentrate on breathing practice and will not be as nervous in the water. 
       SUMMARY OF THE INVENTION 
       [0072]    The design of the swimming machine is very subjective, inventors build it by their personal perception of swimming, and I always compare the swimming profile on my invention to my swimming posture in the water, try to make then consistent. A view of an embodiment of freestyle of the invention is shown in  FIG. 2  for the following description. 
         [0073]    The first thing is to support the full body from head to foot toe like float on water. The head position is a little higher than the foot when swimming, so I use an elongated and inclined board to support the body on land to simulate the floating on the water. 
         [0074]    The arm and hand guide is necessary part which can guide the user to familiar with the arm and hand posture by self practice and reduce the burden of the coach. Our arm and hand guide module use two linear motion systems (or hanging roller and hanging track) as straight line motion guidance which are readily available commodities for any linear motion to use, each has a slide block on the rail and the sliding block can carry thing to sliding on the rail (or has a hanging roller which can also carry thing and sliding inside the track). First install a paddle on each of the slide block, then install a pulley which has outer casing directly on each of the front end of the rail, so each of the pulley is in combination with the rail and integrated as one, connect the two slide blocks with a inelastic rope pass through the two pulleys, an arm and hand guide module is assembled and ready for use. It is an independent module which can be moved to any desired position to operate, the rail prohibits the slide block to rotate and makes only linear motion, the slide block won′ t touch the flat bottom surface of the rail so the rail can be placed on any flat surface to operate the module, the paddle locked on the top of the slide block is always fixed in a upright position and won′ t rotate because the slide block won′ t rotate, the rope which connect the two paddles will not derail from the pulleys&#39; grooves in any case because there are casings encase each of the pulleys, so the cable is always restricted inside the space created by the casing and the pulley groove, the system is completely independent, as shown in  FIG. 9 . It can be suspended on the brackets under the inclined board with Velcro straps to stick on and is very easy to adjust the positions forward or rearward or the width between the pairs for fit different sizes of users. It can be removed from the suspension brackets for storage quickly and easily. When for backstroke use (see  FIG. 10  and  FIG. 11 ), it is an easy job to move the arm and hand guide module from the underside brackets to the supports which is outside of the opposing sides of the inclined board. 
         [0075]    The arms and hand guide module is a straight track with a locked, not rotating paddle rather than the U.S. Pat. No. 6,142,912 (John Profaci) using the contoured, S-shaped tracks with rotatable paddle assembly, the reasons are as follows:
   1. In my personal point of view, the straight arm path stroke is consistent with the trend of modern swimming technique. Straight tracks positioned under and parallel to the body center line can guide the user to maintain streamlined body shape. If we watched the 2012 London Olympics&#39; underwater camera you will see the swimmers drop their arm immediately rather than taking the long route of the S-shape. Dropping your arm results in more direct propulsion force to the back rather than making an S-shape movement that will disperse rearward force.   2. The S shape stroke is always right if you look at a freestyler&#39;s hand from outside bystanders, as it is a combined motion of body rotation and hand pull. But from the freestyler&#39;s own perspective, it is always not necessary to imitate the S-shape pull by hand because combine the contoured, S-shaped path stroke together with body rotation but will distort the forward motion.   
 
         [0078]    The arm and hand guide module give the user a good guideline to do the pull and push of the arm stroke, but the arm is in a horizontal straightening posture before pull the paddle back. When in practice, a horizontal hand stay is used to attract the arm straight forward and hold the arm on the horizon. The horizontal hand stay is a plate with telescopic rods installed on the forefront of the inclined board ahead of the user&#39;s head. It is retractable and can guide the arm straight to front and make the arm remains horizontal. Conjunction use of the arm and hand guide module and the horizontal hand stay, as shown in  FIG. 19 , will guide the user to achieve a complete swimming arm cycle. 
         [0079]    The most distinctive difference with the other inventions is a breathing sink be installed on the forefront gap of the inclined board for breathing practice. No patent reports about breathing sink have ever been found in swim simulator categories. The breathing sink is packed into the front support frame which is the surrounding of the forefront gap of the inclined board. Several blocking things surround the support frame are used to secure the breathing sink. It is better to use a transparent sink for eyes to see far because we don&#39;t like our sight be blocked by a very closed article such as the inclined board, by seeing through the transparent breathing sink and the forefront gap of the inclined board, the user can as seen in the swimming pool water. Even if practice swimming on the land, the breathing sink with water inside gives the user a similar scene like swimming pool. With the emergence of the breathing sink, user can practice the complete swimming skills with breathing on land before entering the water. It is very excited for the user to go to the swimming pool to check if he has learned to swim with on land practice. 
         [0080]    For freestyle, the breathing sink must be work with a body rotation mechanism to perform the breathing movement otherwise we have to turn our heads alone for getting a breath. The neck will hurt with such turn. Breathing for people tends to be the hardest concept to get while putting together the whole strokes. It is why the invention intend to build a breathing sink on the inclined board to practice breathing together with the arms and legs movements. Users may in an unhurried way to practice swimming. But a sink only cannot perform freestyle breathing movement because our body needs to roll from side to side when we breathe; our heads are actually rolled when the body rolls, to get that breath. Since breathing is to rotate the body and the head together, breathing need to turn the head about 90 degrees (from face down direction to face right or face left directions) to get a breath, with the help of a body rotation mechanism, rotate the body for 45 degrees first, for example, then turn the head for the rest 45 degrees to get a breathe. Thus a simulator with good body rotation mechanism is necessary to assist the freestyle breathing be achieved. 
         [0081]    For body rotation mechanism, to solve the bending moment problem and the stable problem of the prior arts, we use an arc panel (or called curved plate) for a contact surface for rotation instead of the crescent shaped support pieces of the U.S. Pat. No. 5,628,632 (Michael P. Doane) and the curved races of the tray of the U.S. Pat. No. 6,142,912 (John Profaci), thus the narrow area of the races or tracks for rotation is substituted by a large piece of curved surface; the whole convex surface of the arc panel is a surface for contact and rotation. Next, support the arc panel with at least two cylindrical conveyor rollers to replace the small contact interfaces of the grooved rollers of the U.S. Pat. No. 5,628,632 (Michael P. Doane) and the small contact interfaces of the channel on the frame of the U.S. Pat. No. 6,142,912 (John Profaci), therefore, the new supporting region covers the whole upper body of the user. The cylindrical conveyor rollers holds the arc panel and drives the arc panel to rotate, as shown in  FIG. 5 . A view of different combinations of rolling elements is shown in  FIG. 6 . From the side view, there is no risk that a bending moment will happen to turn over the arc panel because the center of gravity of the above body always falls inside the front and back support limits of the cylindrical conveyor rollers, so the body rotation mechanism is in a very stable from front to back. Next by the front view, two cylindrical conveyor rollers installed at outmost end points of the inclined board are as wide as the width of the arc panel, but not exceed the width of the arc panel, for a stable support, this can promise the center gravity of the above body supported by the arc panel will never exceed the supporting limits of the outmost two cylindrical conveyor rollers. Several bolts are installed on two opposite edges of the arc panel with arbitrary level for set and limit the rotation angle of the arc panel and could prevent the arc panel turn over from lateral sides. 
         [0082]    In the prior art, in order to fasten or stabilize the torso support or the tray, the elastic band are used. However, the elastic band become a brake of these mechanisms, it means the more angle you rotate your body, the longer the elastic band stretched, and the more efforts you have to pay, the resistance of the elastic band will cause the user to spent more effort to rotate the body, this is contrary to the body rotation of swimming, when we swim in water, the bodies rotate effortlessly, a body rotation mechanism should be rotate freely without the binding force (the elastic band is one of the binding force) and can drive the body to rotate effortlessly, so the prior inventions with elastic band design didn&#39;t satisfy our expectation of body rotation mechanism. 
         [0083]    When the axial torque and lateral stability problems of the prior art are resolved by an example of conjunction use of the arc panel (or curved plate) and the conveyor rollers, a new problem arise: will the rotation center of the body match the rotation center of the arc panel naturally? The answer is no. There are three rotation conditions for the arc panel. 
         [0084]    First, an inverted pendulum motion caused by the rotation center of the body is higher than the rotation center of the arc panel, as shown in  FIG. 17B ; the reason is the diameter of the arc panel is too small for the body or the pad is too thick. This is the same condition as the supporting board and a rotation shaft condition. The body center is above the rotation center of the arc panel so it is unstable and not suitable for a body rotation mechanism. 
         [0085]    Second, a true body rotation motion caused by the rotation center of the body is the same height as the rotation center of the arc panel. This condition is achieved by using a proper thickness of pad to elevate the body&#39;s center to match the rotation center of the arc panel, as shown in  FIG. 7A ; the body will perform a pure body rotation effect just like swimming does, so it is good to be used for freestyle because the proper pad not only overlap the body center and the rotation center of the arc panel but also release the chest pressure. 
         [0086]    Third, a pendulum motion caused by the rotation center of the body is lower than the rotation center of the arc panel. This condition is achieved by let the body lying directly inside the arc panel with no pad or with less pad, as shown in  FIG. 17A . The body center is below the rotation center of the arc panel so it is super stable because once the body rotates to one side, it will be pulled back to the middle by gravity. This is suitable for backstroke use, as shown in  FIG. 7B ; because the back spines won&#39;t feel support pressure like chest, with fewer pads or without pad is not matter. The auto back to middle effect makes the backstroke motion easy and stable, besides, the eyes is in a higher level than the body center, it is close to level of the rotation center of the arc panel, makes user feel no swing of head. A view in  FIG. 7B  shows the backstroke with a pendulum motion. 
         [0087]    To sum up, an apropos arc panel for user means the arc panel is bigger enough to hold the body&#39;s chest, but not too wide to obstruct the arms movement. When pad properly, the two centers overlap and is good for freestyle use. When there is no pad or less pad inside the arc panel, the rotation center of the body is below the rotation center of the arc panel, a pendulum motion formed (as shown in  FIG. 17A ) and is suitable for backstroke use. On the contrary, if padded too high, the over elevated body will swing around the rotation center of the arc panel, an inverted pendulum motion is formed (as shown in  FIG. 17B ) and is not good for body rotation mechanism. We can prepare several thickness of the semi-circular pad to elevate the body&#39;s height for different users until the two centers overlap for a comfortable body rotation but never over padded. Velcro straps are used to fix the semi-circular pad inside the arc panel for easy replacement. 
         [0088]    For breaststroke and butterfly, the body don&#39;t rotate, the body rotation mechanism is not necessary, a not rotating regular torso pad is enough for them, as shown in  FIG. 14  for breaststroke and  FIG. 18  for butterfly. But keeping a body rotation mechanism in use has the merit for practice the body balances because the arc panel will shake the body a small amount of left to right as if the body is in an unbalanced condition in the water.  FIG. 13  shows a breaststroke practice with the body rotation mechanism. 
         [0089]    For backstroke, breathing sink is unnecessary, a pillow is instead for support the face up head, the body rotation mechanism is needed for face up body rotation practice, as shown in  FIG. 10 . 
         [0090]    Legs provide several functions for swimming, some of which directly aid the propulsion, some of which lift the body, some of which balance the arm. So it is necessary to have a surface to provide legs performing above multi-functions for leg kicking practice. So the leg support should slope downward from the longitudinal body line. 
         [0091]    The inclined kicking pad of my invention is an inclined surface pad which has a downward inclined surface relative to the to the inclined board surface, as shown in  FIG. 8A . Without the lower body supporting pad, legs and feet are nowhere to rest on and all the pressure of the body weight will concentrate on the upper body which is the chest and belly position, the chest is uncomfortable under this condition. With the inclined kicking pad to support the lower body, the body pressure is evenly distributed to the whole body just like the buoyancy of the water propped the body. The downward inclined surface of the inclined kicking pad represents a downward maximum foot kicking angle, user may gently lift his leg up to horizontal line and then kick with the instep downward to touch the inclined surface, the inclined surface will give the instep a reaction force like water does, thus guide the user to familiar with a small and steady kick of insteps, as shown in  FIG. 8B . The most important function of the inclined pad is to provide a proper surface for the kicking legs to coordinate the movement of the arm stroke and breathing. Coach may instruct the students to swim with precise timing because the body is always keep Swimming posture supported by the inclined board. For breaststroke, legs are doing longitudinal axial movement; it will retract to the front and kick to the back. A triangle cross section between the legs is formed when the legs retract to the front, we use a column pad which is a bigger bottom area and a smaller top area, to fill the entire space between the legs, as shown in  FIG. 14 , when the legs retract toward the front, they are guided by the sides of the pad; when the kick is completed, allow the straight and closed legs rest on the small area of the top. 
         [0092]    With proper combination of the above mentioned special technical features, swim simulators for different strokes are assembled as follows: 
         [0093]    A swim simulator for freestyle includes (as shown in  FIG. 1 ): 
         [0094]    an inclined board with an opening at the forefront, 
         [0095]    a breathing sink, 
         [0096]    a body rotation mechanism, 
         [0097]    an inclined kicking pad, 
         [0098]    a horizontal hand stay and 
         [0099]    an arm and hand guide module which is suspended under the inclined board and the connecting rope of the two tracks is an inelastic one to perform alternating movement of the two paddles. 
         [0100]    A swim simulator for backstroke includes (as shown in  FIG. 20 ): 
         [0101]    an inclined board, 
         [0102]    a pillow, 
         [0103]    a body rotation mechanism, 
         [0104]    an inclined kicking pad and 
         [0105]    an arm and hand guide module which is support or suspended with independent level supports beside the inclined board and the connecting rope of the two tracks is an inelastic one to perform alternating movement of the two paddles. 
         [0106]    A swim simulator for butterfly includes (as shown in  FIG. 18 ): 
         [0107]    an inclined board with an opening at the forefront, 
         [0108]    a breathing sink, 
         [0109]    a not rotating regular torso pad, 
         [0110]    an inclined kicking pad, 
         [0111]    a horizontal hand stay and 
         [0112]    an arm and hand guide module which is suspended under the inclined board which the connecting rope is an elastic one to perform synchronized motion of the two paddles. 
         [0113]    The swim simulators of butterfly and freestyle have lot in common, we can use the swim simulator of freestyle to practice butterfly just put the inelastic connecting rope into an elastic one, allow the two paddles do the synchronized motion like the arm stroke of butterfly. But on the other hand, without the body rotation mechanism, the swim simulator of butterfly is not suitable be used for freestyle practice. 
         [0114]    A swim simulator for breaststroke includes (as shown in  FIG. 14 ): 
         [0115]    an inclined board with an opening at the forefront, 
         [0116]    a breathing sink, 
         [0117]    a not rotating regular torso pad, 
         [0118]    a specialized breaststroke kicking pad which has cross section of trapezoid or semicircle. 
         [0119]    a horizontal hand stay and 
         [0120]    an arm and hand guide module which is suspended under the inclined board which the connecting rope is an elastic one to perform synchronized action of the two paddles. 
         [0121]    A simplified swim simulator with minimum elements of the above combinations is a board with the body rotation mechanism plus a pad for legs is enough for practice swimming on land, as shown in  FIG. 21 . As rotation of the body is the major simulation movement on land, once we can rotate our body on a dry land like swim, the arms are free to move along the body center line under the board, a basic swimming training can be achieved on land. For experienced swimmer, without arm and hand guide, he can perform his own way of arm stroke. 
         [0122]    The present invention allow user to do the same swimming movements such as freestyle, backstroke, buttery and breaststroke, furthermore, even swimming breathing can be practiced together with. The present invention comprises the adequate lengths of inclined board to support the whole body. The first appeared swimming breathing sink has achieved breathing on land. The body rotation mechanism not only makes rotation for the body but also reserves space for the arms to move under the body. The inclined kicking pad is a surface for legs to kick and allow the legs to coordinate with arms and breathing. The breaststroke trapezoidal column pad especially for breaststroke kicks practice. The straight line arm and hand guide module works with the horizontal hand stay to practice the complete arm movement, all together achieve the goal of simulating swimming on land. Our theory is, once you can do the right swimming technique on land, you can learn to swim very soon. The theory has been confirmed to be true by an experiment of a six year old not swim boy who had practiced swimming with the invention for four times within two weeks, then try a test swim in the water, reached for 20 meters with breathings. 
         [0123]    The object of the present invention is to provide a swim simulator which can practice a complete swimming movement on land which includes breathing. 
         [0124]    It is thus an object of the present invention to provide those schools which have no swimming pools a new tool and method to teach swimming by using the swim simulator on land. 
         [0125]    It is thus an object of the present invention to substitute the swimming pool as the only mean for swimming teaching and learning place, allowing coaches to demonstrate swimming technique and correct the students&#39; swimming movement on land. 
         [0126]    Another object of the present invention is to create a body rotation mechanism for simulating the body rotation effect of freestyle and backstroke on land by use of the arc panel and underside rolling elements. 
         [0127]    Another object of the present invention guides the user to become familiar with the arm cycle by use of the combination of the arm and hand guide module and the horizontal hand stay. 
         [0128]    Another object of the present invention is to provide a linear motion arm and hand guide module to guide the user&#39;s arms to do swimming stroke along the sides of the shoulders for backstroke. 
         [0129]    Another object of the present invention is to provide a quick release arm and hand guide module which can be assembled and disassembled quickly from freestyle use to backstroke use. 
         [0130]    Another object of the present invention is to provide an inclined kicking pad which gives legs and feet a surface to rest and to practice legs kick with insteps. 
         [0131]    Another object of the present invention is to provide a specialized breaststroke kicking pad which is a trapezoid column pad, gives straight legs a narrow surface to rest and retract the legs along the two bevel edges of the trapezoidal column to practice legs kicking of breaststroke. 
         [0132]    Advantageously, the present invention allows user to practice a joint motion of arms, legs and breathing, all work together, with a slow or even paused pose to check each action is correct or not, user may completely ignore the buoyancy problem which will be faced when practice in water because the inclined board always support the body and the user doesn&#39;t has to hold his breath to practice arms and legs joint movements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0133]      FIG. 1  is a perspective illustration showing a user utilizing the appliance in accordance with the present invention to swim freestyle. 
           [0134]      FIG. 2  is a perspective illustration of a swimming appliance in accordance with the present invention. 
           [0135]      FIG. 3  is a perspective illustration of an exemplary appliance of the swimming breathing sink embodying the invention. 
           [0136]      FIG. 4  is an exploded schematic view of an exemplary appliance of the mirrors placed in the side walls of the sink embodying the invention. 
           [0137]      FIG. 5  is a schematic view of one of the embodiments of body rotation mechanism from exploded view to assembled diagram. 
           [0138]      FIG. 6  is a front elevational view of various exemplary structures of the underside rolling support parts of the body rotation mechanism of the invention. 
           [0139]      FIG. 7A  is a front sequential schematic view showing a user rolls by the body rotation mechanism of the invention for freestyle will always keep the body in the center. 
           [0140]      FIG. 7B  is a front sequential schematic view of the invention showing a user rolls by the body rotation mechanism with less or no pad inside to make a stable auto back to middle motion for backstroke. 
           [0141]      FIG. 8A  is a side elevational view of the embodiment of the invention which the surface of the inclined kicking pad is a downward slope with respect to the inclined board and is suitable for the kick practice of freestyle, backstroke and butterfly. 
           [0142]      FIG. 8B  is a side elevational view showing a user practice the legs kick with the instep flat on the inclined kicking pad to simulate the kick in water. 
           [0143]      FIG. 9  includes  FIG. 9A ,  FIG. 9B  and  FIG. 9C  which shows the independent arm and hand guide module is a combination of linear motion systems, shelled pulleys, paddles and rope. 
           [0144]      FIG. 9A  is an exploded view shows a hanging roller inside each of the tracks. 
           [0145]      FIG. 9B  is a perspective illustration shows an embodiment of the invention of the arm and hand guide module which is a combination of tracks, hanging rollers, shelled pulleys, paddles and rope. 
           [0146]      FIG. 9C  is a perspective illustration shows an embodiment of the invention of the arm and hand guide module which is a combination of rails, sliding blocks shelled pulleys, paddles and rope. 
           [0147]      FIG. 10  is a perspective illustration showing a user utilizing the appliance in accordance with the present invention for freestyle to practice backstroke with the breathing sink replaced by a pillow and use four level stands outside the inclined board to support the arm and hand guide module. 
           [0148]      FIG. 11  is a perspective illustration showing a user utilizing the appliance in accordance with the present invention for freestyle to practice backstroke with the breathing sink replaced by a pillow and use invert suspension brackets on each of the four level stands to suspend the arm and hand guide module upside down. 
           [0149]      FIG. 12  is a front elevational view showing a user utilizing the appliance in accordance with the present invention to practice backstroke with adjustable suspension bracket installed on the underside of the inclined board to support and adjust the arm and hand guide module. 
           [0150]      FIG. 13  is a sequential schematic view of the embodiment of the invention for breaststroke with the inclined kicking paid replaced with a trapezoidal column pad, allowing legs to do the kicks of breaststroke. 
           [0151]      FIG. 14  is a perspective illustration of the embodiment of the invention for breaststroke practice which the body rotation mechanism shown in  FIG. 13  is replaced by the general torso pad which will not rotate the body. 
           [0152]      FIG. 15  is a front sequential schematic view showing whether it is a flat (see  FIG. 15A ) or a curved (see  FIG. 15B ) body support, as long as it is driven by a shaft underneath, will cause the above body swaying and off the center line. 
           [0153]      FIG. 16  is a perspective illustration of a redraw of the prior art invention of the U.S. Pat. No. 5,628,632 (Michael P. Doane). 
           [0154]      FIG. 17A  shows the body lying on the arc panel without pad will sway and off the center line like a motion of pendulum. 
           [0155]      FIG. 17B  shows the body lying on the arc panel with an excessively thick pad will sway and off the center line like a motion of invert pendulum as shown in  FIG. 15 . 
           [0156]      FIG. 18  is a perspective illustration showing a user utilizing the appliance in accordance with the present invention to swim butterfly. 
           [0157]      FIG. 19  is a perspective illustration of the embodiment of the arm and hand guide used in conjunction with the horizontal hand stay for a complete arm stroke movement. 
           [0158]      FIG. 20  is a perspective illustration showing a user utilizing a customized appliance in accordance with the present invention special for the backstroke use. 
           [0159]      FIG. 21  is a perspective illustration showing a user utilizing the simplified appliance in accordance with the present invention to practice the coordination of the whole body. 
       
    
    
       [0160]    The same reference numerals refer to the same parts throughout the various Figures. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0161]      FIG. 1  shows a preferred embodiment swim simulator which is to implement the swimming of freestyle. One embodiment of the swim simulator as shown In  FIG. 2  is generally comprised of an inclined board  1  which is supported by descending straight line arranged supporting legs  2 . There are three different height of supporting legs with arithmetic proportion in this example, which are the shortest supporting leg  21 , the longer supporting leg  22  and the longest supporting leg  23 , formed a inclined supporting line. With three legs can prevent the inclined board  1  from bending caused by body weight above it. We use the inclined board  1  rather than a horizontal placed board is to match the true swimming stance, which means the head is higher than the foot when swimming. There is an opening at the front edge of the inclined board  1  which is called the forefront opening  11  and allows the user to see through the inclined board  1  for release pressure of eyesight. 
         [0162]    Above the forefront opening  11  is installed a swimming breathing sink kit  3  which is fixed in position by numbers of blocking things  31  surround the forefront opening  11 . These blocking things  31  can prevent the swimming breathing sink kit  3  from dumping.  FIG. 3  shows an example of the blocking things  31  around the swimming breathing sink kit  3 . The swimming breathing sink kit  3  includes a transparent sink  32  which will give the user a good vision to see the front view by seeing through both the transparent sink  32  and the forefront opening  11 . For practicing swimming breathing, a half full of water is added inside the transparent sink  32  first, mirrors  33  could be stick to the side walls of the transparent sink  32  for the user to view his breathing, as shown in  FIG. 4 . 
         [0163]    An example of body rotation mechanism  4  is shown in  FIG. 5 , which is installed right after the swimming breathing sink kit  3 , is capable of rotating the body rather than swinging the body. It comprises of two parts, the upper part and the under part, the upper part is an arc panel  41  hold a semicircular column pad  47 , the under part is called underside rolling support parts  44 . The function of the arc panel  41  with semicircular column pad  47  is to receive an upper body of the user and drive the upper body to rotate. The underside rolling support parts  44  consists of numbers of cylindrical conveyor rollers  45  or the equivalents and its function is to support and roll the arc panel  41 , several different underside rolling support parts  44  are shown in  FIG. 6 . In this example, the under part consist of two cylindrical conveyor rollers  45  for convenience, installed on the inclined board  1  with locating tabs  46 , side by side with a lateral width smaller than but close to the projection width of the arc panel  41 , thus the arc panel  41  will rotate about its own rotation center but will not overturn. Because the inclined board  1  will cause the arc panel  41  slide to the back when rotating on the two cylindrical conveyor rollers  45 , a rolling barrier component  48  is installed right after the arc panel  41  for stop it from moving and rotate it with low friction. For assemble convenience, the underside rolling support parts  44  and the rolling barrier component  48  can be installed on abase plate  441  first, then fix the whole parts on the inclined board  1 . 
         [0164]    We reserved some space between the cylindrical conveyor rollers  45  and the sides&#39; edge of the inclined board  1  for installing an anti-slip armrest  9  on both sides of the inclined board  1  as shown in  FIG. 2 . The anti-slip armrest  9  is a hand stays for the user easy to get on and off the inclined board  1 . The above arc panel  41  is a curved plate, supported by the two conveyor rollers  45 , they will perform contact rotation, the arc panel  41  will rotate about its virtual rotation center, and the conveyor rollers  45  will rotate at its fixed axis. For elevating the body center of the above user to match the virtual rotation center of the arc panel  41 , we can use thin mats layer by layer to increase the thickness of a semicircular column pad  47 , elevating the center of the body to overlap the virtual rotation center of the arc panel  41 , so when the arc panel  41  rolls, the body will also rotates about the center of itself, thus, a true body rotation movement is achieved, as shown in  FIG. 7A . For different body type, fat or thin, we may prepare several different thicknesses of semicircular column pads  47  to fit everyone. The semicircular column pads  47  can be fastened inside the arc panel  41  with Velcro straps for easy replacement. 
         [0165]    The head of the user will keep in its original position when the body rotates with this body rotation mechanism  4 . Several symmetrical high and low adjusting holes  42  are drilled on the sides of the arc panel  41 , as shown in  FIG. 5 , with some of the adjusting bolts  43  screwed on some of the desired adjusting holes  42 , we can control the rotation angle and prevent turnover of the arc panel  41 . The body rotation mechanism  4  is so stable that when we push the arc panel  41  to one side and then release, it will oscillating and back to the neutral position in the end automatically by gravity, so when the body lying above the arc panel  41  and rolls, it will roll back and forth with ease. Besides, no longitudinal axle bending moment will happen on this body rotation mechanism  4  because the under conveyor rollers  45  support the upper arc panel  41  from front to the end, so no fasten things such as rubber bands are needed to fasten the torso support. Besides, replace a different size of the arc panel  41 , for example, different diameter or different length, for different body type is just a pick it up and put it down procedures. 
         [0166]    An inclined kicking pad  5  installed immediately after the body rotation mechanism  4 .  FIG. 8A  shows an inclined kicking pad  5  which is a triangle from side view and a rectangle from top view. Because the legs kicking of swimming are downward to some depth relative to the longitudinal body center line, the surface of the inclined kicking pad  5  has a more slope downward relative to the inclined board  1 . The surface of the inclined kicking pad  5  is a preset downward kicking slope for legs, when practicing downward kicking, use the instep to kick the inclined kicking pad  5 , make the instep as closely aligns to the surface as possible for getting efficient kick. The surface will provide a reaction force like water resistance to the foot, as shown in  FIG. 8B . A further important function of the inclined kicking pad  5  is to provide legs kick to coordinate with the arms movement, allowing the user to practice timing and the rhythm of the combined movements of arms and legs, finally, swimming breathing will be joined for a complete swimming technique practice on land. The inclined kicking pad  5  is a simple but important board for the practice of the kick of freestyle, backstroke and butterfly. 
         [0167]    An arm and hand guide module  6  is a guidance of all strokes, for freestyle, it is suspended by brackets  61  under the inclined board  1 . We use the linear motion systems which are mature and readily available commodities as the straight-line gliding mechanism. It is consist of a track  62  to guide a hanging roller  63  or a rail  64  to guide a sliding block  65 , as shown in  FIG. 9 . The track  62  and the hanging roller  63  are operated in a upside down position compared to its normal use, so the hanging roller  63  can moves inside the track  62  and allowing a paddle  66  be installed on top of the standup hanging roller  63 . When using the rail  64  and the sliding block  65 , the paddle  66  is installed directly on top of the sliding block  65 . A shell pulley  67  is installed at the front end of the track  62 , we need two sets of this linear motion systems for both arms, by connecting both paddles  66  through the shell pulleys  67  with a inelastic connecting rope  68 , the two paddles  66  on each hanging roller  63  are linked now and the inelastic connecting rope  68  will not derail in any case, no matter the inelastic connecting rope  68  is tight or loose, the paddles  66  will guide the arms to do the freestyle arm cycle by turns. The arm and hand guide module  6  can be fixed on the brackets  61  with screws, but for easy to adjust and quick releases, Velcro straps are used to secure the tracks  62  on the brackets  61 . When different users come to use one after another, it is very quick to adjust the track  62  position back and forth to fit each user&#39;s hand position. Because the tracks  62  exceed the inclined board  1  a lot, when not in use, we can take down the arm and hand guide module  6  from the brackets and store it under the inclined board  1  for space saving. 
         [0168]    A horizontal hand stays  7  is consist of two parts, a set of telescopic rails  71  and a palm-rest plate  72 , as shown in  FIG. 8A . The telescopic rails  71  are installed under the forefront opening  11  of the inclined board  1 ; the palm-rest plate  72  is installed on the other end of the telescopic rails  71 . By stretching the telescopic rails  71 , we can adjust the position of the palm rest plate  72 , for matching hand of different arm length to stay, as shown in  FIG. 8B . The horizontal hand stays  7  will be used in conjunction with the arm and hand guide module  6  to perform the complete arm cycle of swimming. The horizontal hand stays  7  is responsible for the palm entering the water period and the arm and hand guide module  6  is responsible for the following pull, push and recovery periods and back to the palm-rest plate  72  for the next arm cycle. The palm-rest plate  72  will keep the front arm maintaining level to reduce forward resistance while the other arm is pushing the paddle  66  back to the thigh meanwhile the feet are kicking downward to the inclined kicking pad  5 . The combined use of the arm and hand guide  6  and the horizontal hand stays  7  is shown in  FIG. 19   
         [0169]    An elastic mark rod  8  is fixed on two opposite sides of the inclined board  1  adjacent to the sink  3  as shown in  FIG. 2 . The purpose of the elastic mark rod  8  is a marking of water level, for reminding the user to raise his arm high enough to cross the water surface when the arm recovered to the front of the arm cycle. Without the elastic mark rod  8 , novices often forget keeping their elbows high during recovery period, the mark rod  8  could be folded under the surface when users familiar with arm stroke. 
         [0170]    An anti-slip armrest  9  is installed on two opposite sides of the inclined board  1  adjacent to the body rotation mechanism  4  as shown in  FIG. 2 . It provides the user a place to grab for getting on and off the inclined board  1 . 
         [0171]    For backstroke, the swimming breathing sink  3  is replaced by a pillow  34  for supporting the head and the horizontal hand stays  7  is not needed. The arms stroke of the backstroke are along the sides of the body, unlike the arms are under the body of freestyle, so the two tracks  62  of the arm and hand guide module  6  is moved to positions parallel to and with a distance outside the inclined board  1 . Three embodiments are shown here, one is the arm and hand guide module  6  be placed beside the inclined board  1  and the paddles  66  position are below the body level, as shown in  FIG. 10 , the arm moves in a wide and deep pull and push, each track  62  is supported by two independent level stands  10 , choose a proper width between inclined board  1  and the tracks  62  for different user&#39;s need by adjusting the level stands  10  to create adequate space for the arm and elbow to move through. Because the two tracks  62  of the arm and hand guide module  6  is positioned wider than for freestyle, the connecting rope  68  must be replaced by a longer one to compensate the increased width between the two tracks  62 , once the connecting rope  68  is changed to a suitable one, the arm and hand guide module  6  is ready for backstroke use. Another embodiment is hung upside down the arm and hand guide module  6  with the height above the body, by Installing the invert suspension brackets  101  on the level stands  10  to increase suspension height, the tracks are suspended upside down on the invert suspension brackets  101 , as shown in  FIG. 11 , this embodiment guides the arms doing a narrow arm pull and push stroke which the arms are very close to the sides of the body. The installation of the invert suspension is a little bit complex than the previous one but runs very smooth and may keep the body in a straight line move. 
         [0172]    The other embodiment is to install four adjustable suspension brackets  102  on the underside of the inclined board  1  as shown in  FIG. 12 . The backstroke suspension brackets  102  are articulated bracket which consist of plural of pipes connected by knuckle Joints, here we use the combination of two pipes to demonstrate the assembly of one adjustable suspension brackets  102 , we need four of the two pipes for the front pair and the rear pair, one end of the adjustable suspension brackets  102  is fixed on the bench board  1  and the other end is to support the track  62 , with the knuckle Joints, the joint angle of the adjustable suspension brackets  102  can be adjusted between the bench board  1  and the paddle  66 , to match the unique arm need for different users. 
         [0173]    For butterfly, as shown in  FIG. 18 , all parts are the same as used in freestyle except the following two, the body rotation mechanism  4  and the arm and hand guide module  6 . The body rotation mechanism  4  could be replaced by a not rotating regular torso pad  49  for economic consideration, but it is not necessary if you already have a body rotation mechanism  4  for freestyle because a left and right balance of body could be practiced with the little shake of the body rotation mechanism  4 . The arm and hand guide module  6  for butterfly needs to move the two paddles  66  with a synchronized motion, by replacing the inelastic connecting rope  68  used for freestyle with a elastic connecting rope  69 , the user can pull the two paddles  66  with synchronized motion to the back, when both arms leave the paddles  66  and recovered to the front horizontal hand stays  7 , the two paddles has already pull to the front by the elastic connecting rope  69  and ready for the next pull. 
         [0174]    For breaststroke, all parts are the same as used in freestyle except the following three, the body rotation mechanism  4 , the arm and hand guide module  6  and the inclined kicking pad  5 . The body rotation mechanism  4  could be replaced by a not rotating regular torso pad  49  for avoiding the rear edge of the arc panel  41  of the body rotation mechanism  4  obstruct the legs retraction movement to the front as shown in  FIG. 13 . The arm and hand guide module  6  for breaststroke is the same type as used in butterfly with the connecting rope  69  be elastic and also suspend under the inclined board  1 . To ensure unobstructed legs kicking practice, replace the inclined kicking pad  5  by a specialized breaststroke kicking pad  51  as shown in  FIG. 14 . When swimming, retracting legs of the breaststroke is done by spread out and bends the legs to the front, a triangular or trapezoidal space is formed between the two legs. We could use a pad which is a bottom wide and top narrow shape to match the angle of the spread legs, such as a trapezoid or a semicircle are two of the same types, here we use a trapezoidal column as the example of the specialized breaststroke kicking pad  51 . The top narrow area is able to support the legs when the two legs are straight toward the back and draw close, the bevel edges of the trapezoidal column will support and guide the legs to spread and move to the front. When the legs kick to the back and will stay on the top narrow area with the two legs straight again. In  FIG. 21 , the other embodiment is for the beginners. By using only a narrow board to support the lying body and a body rotation mechanism  4  to rotate the bodies while the arms can move freely under the bodies, plus an inclined kicking pad  5  or a readily available common pad, is enough for them to practice the basic technique with a lying posture like swimming. Coaches may also demonstrate dedicated swimming skills with lie down posture and without the limitation of the arm and hand guide module  6 . 
       REFERENCE NUMERALS AND DESIGNATIONS 
       [0000]    
       
         
           
               1 . inclined board 
               11 . forefront opening 
               2 . descending straight line arranged supporting legs 
               21 . the shortest supporting leg 
               22 . the longer supporting leg 
               23 . the longest supporting leg 
               24 . adjustable supporting leg 
               25 . hinge 
               3 . swimming breathing sink 
               31 . blocking things 
               32 . transparent sink 
               33 . mirror 
               34 . pillow 
               4 . body rotation mechanism 
               41 . arc panel 
               42 . adjusting hole 
               43 . adjusting bolt 
               44 . underside rolling support parts 
               441 . base plate 
               45 . conveyor roller 
               46 . locating tab 
               47 . semicircular column pad 
               48 . rolling barrier component 
               49 . not rotating regular torso pad 
               5 . inclined kicking pad 
               51 . specialized breaststroke kicking pad 
               6 . arm and hand guide module 
               61 . bracket 
               62 . track 
               63 . hanging roller 
               64 . rail 
               65 . sliding block 
               66 . paddle 
               67 . shell pulley 
               68 . inelastic connecting rope 
               69 . elastic connecting rope 
               7 . horizontal hand stay 
               71 . telescopic rail 
               72 . palm rest plate 
               8 . elastic mark rod 
               9 . anti-slip armrest 
               10 . level stand 
               101 . invert suspension bracket 
               102 . adjustable suspension bracket