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CROSS-REFERENCES TO RELATED APPLICATIONS 
     None 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates to devices assisting the removal and replacement of covers used with spas and swim spas, specifically to a cover lifter usable with swim spas holding approximately 20,000 gallons of water and having a large cover, that is also adjustable for alternative use with smaller spas only holding about 800 gallons of water and having a much smaller cover. The present invention cover lifter is also adjustable for use with covers for spas and swim spas having different thickness dimensions. In addition, it has upper portions that can be promptly removed from and reattached to its footplate in only a few minutes, allowing spa maintenance without having to empty and refill the associated spa or swim spa, and overcoming a significant disadvantage of the prior art. 
     The present invention spa and swim spa cover lifter is also structurally sounder and stronger than known spa and swim spa cover lifters for long-term repeat use with the larger and heavier covers of swim spas, which are gaining in popularity. In addition, the present invention&#39;s triangular braces on the larger ones of its L-shaped brackets assist in lateral support for raised elevation of its J-shaped arms up to approximately 48-inches, whereas the known prior art only extends upwardly to a height of approximately 21-inches. The present invention spa and swim spa cover lifter comprises a footplate with an elongated undermount portion that is completely positioned under the spa or swim spa when the present invention is in its position of use, two vertically-extending supports each having two L-shaped brackets for lateral support permanently secured to its lower end, and a total of six easily separated two-part fasteners, three of which are used to releasably connect each of the vertically-extending supports and its attached L-shaped brackets to the exposed portion of the footplate depending from the elongated undermount hidden under the spa or swim spa during present invention use. A pre-assembled body having a rotation axis and hydraulic lift is releasably attached to the upper ends of the two vertically-extending supports, and is used to raise and lower two connected adjustable and movable J-shaped spa and swim spa cover support arms secured to the upper end of its hydraulic lift. The vertically-extending supports are configured to provide alternative height positioning for the cover support arms, a lower elevation for use with a spa cover, and a higher elevation for use with a swim spa cover. Furthermore, to achieve quick and easy release of the vertically-extending supports from the footplate and their prompt reinstallation thereto at a later time, one part of each fastener, preferably the bolt portion (although the nut or bolt cap used could be substituted), is welded and/or otherwise permanently secured to the footplate. The lifting-assist/lowering-assist hydraulic member is shown in the accompanying illustrations only between the J-shaped cover support arms and on one side of the present invention pre-assembled body, however, this structural limitation is not considered critical. 
     Description of the Related Art 
     Spa cover lifters and support apparatus are known to assist the removal of a cover prior to spa use, and replacement of the cover when spa use is complete. A disadvantage of known spa cover lifters is that many have structures necessitating attachment to the exterior surface of a spa or swim spa, and also attachment to the spa&#39;s cover, which at least in part blocks convenient access to the spa&#39;s water circulation equipment when maintenance, inspection, or repair is needed. To remove these cover lifters requires emptying of water from the spa and later refilling it, adding to the time and expense involved. Since the upper portions of the present invention are easily and promptly separated and removed from the present invention footplate, its use allows immediate access to the spa&#39;s water circulation equipment without having to empty water from the spa, overcoming a significant disadvantage of the prior art. One U.S. Pat. No. 6,381,766 to Perry (May 7, 2002) is known to disclose a pair of base plates  48 , which in its  FIGS. 4 and 5  are each shown to be positioned in part under a different lateral portion of a spa, in opposed positions to one another. However, as can be also seen in the same  FIGS. 4 and 5 , the undermount portion of the Perry invention is much smaller in surface area than that in the applicant&#39;s invention, it does not have the same configuration as the present invention footplate, and the Petty base plates  48  are not centrally located under the spa. As a result, the Perry invention would have insufficient strength and stability to lift the larger swim spa covers to a raised height of approximately 48-inches. In addition, the Perry invention is different from the present invention as it has connections to opposed lateral exterior surfaces of a spa, as well as to opposed lateral exterior surfaces of the spa cover, both of which the present invention lacks. No invention is known to have all of the features and advantages of the present invention. 
     SUMMARY OF THE INVENTION 
     The primary objective of this invention is to provide an adjustable cover lifter that can be alternatively used for spas and swim spas of differing height, as well as with spa and swim spa covers having differing thickness dimensions. It is a further objective of this invention to provide a spa and swim spa cover lifter having upper portions that can be easily and promptly removed from its footplate, and later easily and promptly reattached thereto, without having to empty water from the associated spa or swim spa for maintenance, inspection, and/or repair purposes. It is also an objective of this invention to provide a spa and swim spa cover lifter that is strengthened for extended stable use with heavy swim spa covers up to a raised elevation of approximately 48-inches. In addition, it is an objective of this invention to provide a spa and swim spa cover lifter that is made from strong and durable materials that are resistant to premature deterioration from exposure to spa chemicals, cleaning agents, and outdoor weathering elements. It is also an objective of this invention to provide a spa and swim spa cover lifter with fasteners that easily release the vertically-extending supports from the footplate without the need for a tool. A further objective of this invention is to provide a spa and swim spa cover lifter that is cost efficient in design and construction, and able to achieve a compact collapsed configuration for low-profile and unobtrusive storage against the side of a spa or swim spa. 
     The present invention is a spa and swim spa cover lifter with upper portions that can be promptly removed from and reattached to its footplate for spa maintenance purposes without having to empty and refill the associated spa or swim spa, overcoming a significant disadvantage of the prior art. It is also strengthened over known spa and swim spa cover lifters for long-term repeat use with the larger and heavier covers of swim spas for extended periods of time at elevations up to approximately 48-inches. The present invention spa and swim spa cover lifter comprises a footplate with an elongated undermount portion that is completely positioned centrally under one side of the spa or swim spa when the present invention is in its position of use, two vertically-extending supports each with two lateral-sway-reducing L-shaped brackets secured to its lower end (one smaller and the other larger with its vertically-extending portion in the shape of a substantially triangular brace), and a total of six easily separated two-part fasteners, three of which are used to releasably connect each of the vertically-extending supports, as well as its attached L-shaped brackets, to the exposed portion of the footplate depending outwardly beyond the side wall of the associated spa or swim spa, while its elongated undermount remains hidden under the spa or swim spa during present invention use. A pre-assembled body, which includes connected adjustable J-shaped spa cover support arms and a lifting-assist/lowering-assist hydraulic member, is secured to the upper ends of the vertically-extending supports with two height adjustment knobs, with the vertically-extending supports allowing alternative positioning of the support arm at a lower elevation for use with a spa cover, or at a higher elevation for use with a swim spa cover. To achieve quick and easy release of the vertically-extending supports from the footplate while the elongated undermount of the footplate remains under the spa or swim spa, one portion of the fastener (preferably the bolt) is welded and/or otherwise permanently secured to the footplate, providing rotational leverage while the upper portion of the fastener is released and later reattached. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is an exploded view of the footplate with elongated undermount, vertically-extending supports, fasteners, and L-shaped brackets used as a part of the most preferred embodiment of the present invention, with broken lines indicating preferred locations of fastener connection. 
         FIG. 2  is an enlarged perspective view of the reverse side of one of the two vertically-extending supports shown in  FIG. 1 , and the welded connection of the vertical portion of the smaller L-shaped bracket to the vertically-extending support. 
         FIG. 3  is an enlarged view of the footplate shown in  FIG. 1  to which one part of the two-part fasteners used with the most preferred embodiment of the present invention are permanently secured, preferably via a welded connection. 
         FIG. 4  is a perspective view of the assembly in  FIG. 1  from the rear that is further shown with pre-assembled body secured to the upper ends of the vertically-extending supports via two height adjustment knobs, the pre-assembled body including two connected and adjustable J-shaped cover support arms, the cover support arms each having two expandable joints to accommodate spa and swim spa covers of differing thickness and length dimension, and the cover support arms also shown rotated into the raised and substantially horizontally-extending orientation needed to receive a spa or swim spa cover. 
         FIG. 5  is an enlarged view from the side showing one of the cover support arms in  FIG. 4  and the preferred configuration and positioning of its expandable joints. 
         FIG. 6  is a front view of the most preferred embodiment of the present invention shown in  FIG. 4 , with its cover support arms in a substantially vertically-extending orientation used to support a spa or swim spa cover in an out-of-the-way/remote position during spa or swim spa use, the cover support arms not showing the expandable and rotating joints preferred to accommodate spa and swim spa covers of differing thickness and length. 
         FIG. 7  is perspective view from the top of a spa with the most preferred embodiment of the present invention shown in  FIG. 4  secured against one side of the spa, the spa cover deployed completed over the top of the spa and the present invention shown in a collapsed, compact, and low-profile storage configuration. 
         FIG. 8  is perspective view from the top of a spa and present invention shown in  FIG. 7 , with half of the spa cover folded toward the present invention, the present invention shown in a raised and horizontally-extending orientation ready to receive the spa cover, and arrows pointing in the direction that the spa cover would be moved into the J-shaped cover support arms of the present invention to allow spa use. 
         FIG. 9  is perspective view from the top of a spa without a cover, the pre-assembled body with its J-shaped cover support arms removed from the vertically-extending supports, and the portion of the present invention shown in  FIG. 1  remaining and still having the elongated undermount portion of its footplate centrally beneath one side of the spa. 
         FIG. 10  is perspective view from the top of the spa in  FIG. 9 , the vertically-extending supports removed from the footplate to expose the portions of the six fasteners permanently attached to the footplate. 
     
    
    
     COMPONENT LIST 
     
         
           1 —Removable Swim Spa Cover Lifter with Undermount 
           2 —Footplate (preferably eight-sided) 
           3 —Elongated Undermount portion/end of footplate  2   
           4 —Two Vertically-Extending Supports (they have lateral positioning on footplate  2 , are releasably secured to footplate  2 , and provide adjustability for the J-shaped cover arms  11  to receive spa and swim spa covers  19  at differing position heights) 
           5 —Outside Surface of vertically-extending support  4  (remotely located from the opposed vertically-extending support  4 ) 
           6 —Inside Surface of vertically-extending support  4  (located in a position facing the other laterally positioned vertically-extending support  4 ) 
           7 —Larger L-Shaped Bracket having a vertically-extending surface providing a substantially triangular brace  17  (L-shaped bracket  7  is removably connected to footplate  2 , but permanently fixed to the outside surface  5  of a vertically-extending support  4 ) 
           8 —Smaller L-shaped Bracket (connected between footplate  2  and the inside surface  6  of a vertically-extending support  4 , with permanent connection to the vertically-extending support  4  and releasable connection to footplate  2  via fasteners  9 / 10 ) 
           9 —Fastener (three are used with each vertically-extending support  4  to removably attach it to footplate  2 , fasteners  9  and bolt caps  10  together provide three points of attachment for lateral support of vertically-extending supports  4  under load and one part thereof is preferably welded to footplate  2 ) 
           10 —Bolt Caps (rounded head nuts are preferred for easy hand-manipulation without tools) 
           11 —Two J-shaped Spa Cover Support Arms 
           12 —Lifting-Assist/Lowering-Assist Hydraulic Member connected to pre-assembled body  22  and used for rotation of J-shaped cover support arms  11  about rotation axis  24  between a raised position to receive a spa or swim spa cover and multiple lowered positions 
           13 —Height Adjustment Knobs used between pre-assembled body  22  and each vertically-extending support  4 , aligning the height of cover support arms  11  to the height of the spa or swim spa cover  19  (typically threaded, and configured for manual tightening) 
           14 —Two Expandable Joints on each J-shaped cover support arm  11  (each joint is expandable in two places, the joints closer to the distal ends of the cover support arms  11  allowing for width adjustment of the cover support arms  11  to accommodate different spa cover  19  thickness, and the joints closer to the pre-assembled body  22  allowing for length adjustment of the larger covers  19  of swim spas, the lengthening joint also allowing rotation of cover support arms  11  for collapsed/compact storage in a low-profile and unobtrusive position adjacent to a spa or swim spa  18 , see  FIG. 7 ) 
           15 —Multiple Holes in vertically-extending support  4  used for height adjustment of the connected J-shaped cover support arms  11  from a lower position usable with a smaller spa cover to a higher position needed for use with a swim spa cover  18   
           16 —Welded Connection and/or other strong/secure connection between the vertically-extending supports  4  and portions of the two L-shaped brackets  7  and  8  (although not revealed in the views of the accompanying illustrations, welded connection  16  is also used between substantially triangular brace  17  and the adjacent vertically-extending support  4 , between the lower end of each vertically-extending support  4  and the horizontally-extending portion of a larger L-shaped bracket  7  and to secure fasteners  9  to footplate  2 ) 
           17 —Substantially Triangular Brace comprising the vertically-extending surface of the larger L-shaped bracket  7   
           18 —Spa or Swim Spa 
           19 —Cover for a spa or swim spa 
           20 —Multiple Holes through footplate  2  and into which fasteners  9  are securely fixed 
           21 —Two Fastener Holes through L-shaped bracket  7  and One Fastener Hole through L-shaped bracket  8  each used for the insertion of a different fastener  9   
           22 —Pre-Assembled Body (includes the connected J-shaped cover support arms  11  and the hydraulic lifting-assist/lowering-assist member  12 ) 
           23 —Adjustment Push Pins (in expandable joints  14 , see  FIG. 5 ) 
           24 —Rotation Axis on pre-assembled body  22  (allows rotational movement of connected cover support arms  11  between raised and lower positions) 
       
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is a spa and swim spa cover lifter  1  having the elongated undermount portion/end  3  of its footplate  2  positioned under an adjacent spa or swim spa  18 , two vertically-extending supports  4  upwardly-depending from the wider and non-elongated portion/end of footplate  2 , and a pre-assembled body  22  (that includes two connected J-shaped cover support arms  11  and a lifting-assist/lowering-assist hydraulic member  12 ) connected to the top ends of the vertically-extending supports  4  using two height adjustment knobs  13 . The vertically-extending supports  4  and the cover support arms  11  provide adjustment means for present invention  1 , allowing the present invention spa and swim spa cover lifter  1  to be used with both spas and swim spas  18 , as well as a variety of spa and swim spa covers  19  having differing length and thickness dimensions. Since swim spa covers  19  are typically heavy, lifting-assist/lowering-assist hydraulic member  22  extends between the connected cover support arms  11  and the remainder of pre-assembled body  22  for controlled rotation of cover support arms  11  about a rotation axis  24  for removal and replacement of the spa or swim spa cover  19 . Furthermore, since one part of each two-part fastener ( 9 ,  10 ) fixing the vertically-extending supports  4  to the present invention footplate  2  is permanently attached to the footplate  2 , the vertically-extending supports  4  can be promptly released from, and reconnected to, the footplate  2  for spa or swim spa  18  maintenance without having to remove water from the spa or swim spa  18 , saving time and expense. When the word ‘spa’ is used hereinafter, it is intended that its use includes both spa and swim spas, unless otherwise indicated in the context. 
       FIGS. 1-6  show varying views of the most preferred embodiment of the present invention.  FIG. 1  is an exploded view of the footplate  2  with its elongated undermount  3 , two vertically-extending supports  4 , six fasteners  9 , six rounded head nuts  10 , and four L-shaped brackets  7  and  8  used as a part of the most preferred embodiment of the present invention  1 , with broken lines indicating preferred locations of fastener  9  and nut  10  connections. Each of the L-shaped brackets has a substantially vertically-extending portion depending upwardly from a substantially horizontally-extending portion, and as shown in  FIG. 1 , two of the four L-shaped brackets are larger and provide more connecting surface area than the two smaller L-shaped brackets. In addition,  FIG. 1  shows the vertically-extending portions of the larger L-shaped brackets  7  each providing a substantially triangular brace that is larger in surface area than its substantially rectangular horizontally-extending portion, while each of the smaller L-shaped brackets  8  has vertically-extending and horizontally-extending portions that are similar to one another in their size and substantially rectangular shape.  FIG. 1  shows footplate  2  having an eight-sided perimeter (preferably with rounded corners, but not limited thereto), with fasteners connecting vertically-extending supports  4  in laterally opposed positions on its wider end that is situated remotely from its elongated undermount portion  3 . The outside surface  5  on the vertically-extending supports  4  is designated as being in a remote position from the opposed vertically-extending support  4 . In contrast, the inside surface  6  of the opposing vertically-extending support  4  is designated as being in a position facing the other support  4 . The substantially triangular-shaped braces  17  in the larger L-shaped brackets  7  used as a part of the most preferred embodiment of the present invention  1  each have a fixed connection (preferably via welding) to the outside surface  5  of a different one of the vertically-extending supports  4 , with the lower end of the same vertically-extending support  4  also fixed (preferably via welding) to the horizontally-extending portion of the larger L-shaped bracket  7  depending from the vertically-extending brace  17 . However, the connection of the two larger L-shaped brackets  7  to footplate  2  is easily releasable, and preferable via two-part fasteners ( 9 ,  10 ), with one portion of each two-part fasteners  9 ,  10  (preferably fastener  9 , but possibly nut  10 ) welded (or otherwise fixed permanently) to footplate  2 .  FIG. 1  further shows each of the two smaller L-shaped brackets  8  connected between footplate  2  and the inside surface  6  of a different one of the vertically-extending supports  4 . The sizes, configurations, and relative positioning of the footplate  2 , smaller L-shaped brackets  8 , larger L-shaped brackets  7 , and vertically-extending supports  4  may vary somewhat from that shown, and that shown in  FIG. 1  should not be strictly considered as limiting as long as each effectively fulfills its intended function. 
       FIG. 2  is an enlarged perspective view of one of the two vertically-extending supports  4  shown in  FIG. 1 , while  FIG. 3  is an enlarged view of the footplate shown in  FIG. 1  to which one part (fastener  9 ) of the six two-part fasteners  9 ,  10  used with the most preferred embodiment of the present invention  1  is secured as a separate attachment point for vertically-extending supports  4  to footplate  2 , for reduced lateral sway when vertically-extending supports  4  become positioned at a raised elevation of approximately 48″ under load.  FIG. 2  shows the holes  15  in each vertically-extending support  4  that allow height adjustment of the pre-assembled body  22  and J-shaped cover support arms  11  for use alternatively with smaller spas and larger swim spas.  FIG. 2  also better shows the substantially triangular-shaped brace  17  associated with the larger L-shaped bracket  7 , and the welded connection  16  of the vertical portion of the smaller L-shaped bracket  8  to the inside surface  6  of vertically-extending support  4 . The larger L-shaped bracket  7  is shown to have two holes  21  for releasable attachment to footplate  2  via two fasteners  9  and two rounded head nuts  10 , and the smaller L-shaped bracket  8  is shown to have one hole  21  for releasable attachment to footplate  2  using one fastener  9  and one rounded head nut  10 . Although not shown in  FIG. 2 , it is also contemplated for the substantially triangular-shaped brace  17  associated with the larger L-shaped bracket  7  to have welded connection  16  to the outside surface  5  of vertically-extending support  4 . In addition,  FIG. 3  more clearly defines the configuration of the elongated undermount  3  of footplate  2  through use of a bracket connected to the line extending from the numeral  3 . 
       FIGS. 4-6  show the pre-assembled body  22  and connected J-shaped arms  11  as they are used as a part of the most preferred embodiment of the present invention  1 .  FIG. 4  is a perspective view of the present invention from the rear (side facing a spa or swim spa  18 ) and shows the pre-assembled body  22  secured to the upper ends of the vertically-extending supports  4  via height adjustment knobs  13  that lock the releasable but temporarily fixed positioning of pre-assembled body  22  to the vertically-extending supports  4  at a selected height.  FIG. 4  also shows a lifting-assist/lowering-assist hydraulic member  12  connected to pre-assembled body  22  to help raise and lower J-shaped cover support arms  11  about a rotation axis  24  under load. As shown in  FIGS. 4 and 5 , the cover support arms  11  include expandable joints  14  allowing accommodation of spa and swim spa covers  19  of differing thickness and length. In addition the expandable joints  14  providing length accommodation also allow cover support arms  11  to rotate toward and away from one another. This allows the cover support arms  11  to remain open while in the raised and horizontally-extending orientation needed to receive a spa or swim spa cover  19 , yet also achieve a low-profile configuration for compact storage when not in use.  FIG. 6  also shows the lifting-assist/lowering-assist hydraulic member  12  connected between the connected J-shaped cover support arms  11  and the lower portion of the pre-assembled body  22 .  FIG. 6  further shows the most preferred embodiment of footplate  2  having an eight-sided perimeter, with rounded head nuts  10  securing the two vertically-extending supports  4  via the four L-shaped brackets  7  and  8  shown to hidden fasteners  9  fixed to footplate  2  in positions remote from the elongated undermount portion  3 . The connection of L-shaped brackets  7  and  8  to footplate  2  is fixed, but releasable.  FIG. 5  is an enlarged view from the side of the expandable joints  14  in one of the cover support arms  11  shown in  FIG. 4 , which also shows the adjustment push pins  23  used for lengthening and widening cover support arms  11  to accommodate spa and swim spa covers  19  of differing length and thickness dimension.  FIG. 6  is a front view of the most preferred embodiment of the present invention shown in  FIG. 4 , with its cover support arms  11  in a vertically-extending orientation used to support a spa or swim spa cover  19  in an out-of-the-way/remote position during spa or swim spa use, the cover support arms  11  not showing the expandable joints  14  preferred to accommodate spa and swim spa covers  19  of differing thickness and length. 
       FIGS. 7-10  show the most preferred embodiment of the present invention  1  associated with a spa or swim spa  18  in varying configurations and states of disassembly.  FIG. 7  is perspective view from the top of a spa  18  with the most preferred embodiment of the present invention  1  centrally against one side of spa  18 , the spa cover  19  deployed completely over spa  18 , and the present invention  1  shown in a collapsed, compact, and low-profile configuration. In contrast,  FIG. 8  is perspective view from the top of a spa  18  and present invention  1 , with half of the spa cover  19  folded toward present invention  1  over the other half of spa cover  19 . The present invention  1  is further shown in a raised and horizontally-extending orientation to receive the spa cover  19  while in its folded configuration. Arrows point in the direction that the spa cover  19  would be moved into the J-shaped cover support arms  11  of present invention  1  to allow unencumbered spa  18  use.  FIG. 9  is perspective view from the top of a spa  18  and the portion of the present invention  1  without its pre-assembled body  22  or J-shaped cover support arms  11 .  FIG. 10  is perspective view from the top of a spa  18  and the present invention footplate  2  without the vertically-extending supports  4  attached thereto, leaving its permanently attached fasteners  9  exposed. 
     To assemble and use the present invention  1 , one first attaches the vertically-extending supports  4  to the footplate  2  using the pre-installed bolts  9  permanently fixed to footplate  2 , and preferably fixed thereto via a welded connection  16 . The substantially triangular-shaped brace portions  17  of the two L-shaped brackets  7  should face away from the elongated undermount  3  portion of footplate  2 . When the spa or swim spa  18  is empty and unplugged, the elongated undermount  3  portion of footplate  2  can be slid under the center part of spa or swim spa  18  along one of its sides, and the user must be sure that footplate  2  is flat on the ground. The pre-assembled body  22  is then slid downwardly over the upper ends of both of the vertically-extending supports  4 , with the connected J-shaped arms  11  facing away from the spa or swim spa  18 . The J-shaped arms  11  are next adjusted to the height of the spa or swim spa  18  and its cover  19 . The two holes in the bottom part of the pre-assembled body  22  will line up with one of the holes  15  in the vertically-extending supports  4 , which are then secured together by inserting each of the two height adjustment knobs  13  through a hole  15  in a different one of the vertically-extending supports  4 . Both height adjustment knobs  13  are then firmly tightened to securely fix together the pre-assembled body  22  and the vertically-extending supports  4 . Once height adjustment knobs  13  are in place, the J-shaped arms  11  can be elevated into a raised position and the engagement of adjustment push pins  23  thereafter will allow the J-shaped arms  11  to be opened away from one another, allowing the J-shaped arms  11  to properly accommodate the thickness and length of the spa or swim spa cover  19  (when folded in half), with the length of the J-shaped arms  11  arms set to keep the spa or swim spa cover  19  as low as possible without hitting the ground. When proper adjustments are made, the spa or swim spa cover  19  should slide easily into the J-shaped arms  11 . The hydraulic lift  12  can be used to tilt the spa or swim spa cover  19  into an out-of-the-way position during spa or swim spa  18  use. 
     While the written description of the invention herein is intended to enable one of ordinary skill to make and use its best mode, it should also be appreciated that the invention disclosure only provides examples of specific embodiments and methods, and many variations, combinations, and equivalents also exist which are not specifically mentioned. The present invention should therefore not be considered as limited to the above-described embodiments, methods, and examples, but instead encompassing all embodiments and methods within the scope and spirit of the invention as disclosed in the accompanying claims.

Summary:
A spa and swim spa cover lifter having a footplate with an elongated undermount that becomes secured under a spa or swim spa for added lifter stability and strength during the raising and lowering of a spa cover. The upper structure of the cover lifter is quickly and easily separated from the footplate, allowing its prompt removal for spa maintenance without the burden/expense of emptying and refilling the spa. The upper structure comprises two vertically-extending supports each having two permanently attached L-shaped brackets providing lateral sway reduction for the vertically-extending supports under load. Three fasteners removably secure each vertically-extending support and its two associated brackets to the wider/exposed end of the footplate. The bottom part of each fastener is permanently fixed to the footplate, preferably by welding. A pre-assembled body comprising adjustable spa cover support arms and lifting-assist/lowering-assist means is fixed to the vertically-extending supports using two height adjustment knobs.