1. Field of the Invention
The present invention relates to containers of liquid such as swimming pools, hot tubs, spas, swim spas, and the like, and, more particularly, to automatic cover assemblies for such containers.
2. Description of the Related Art
Swimming pools, for example, are commonly covered to prevent debris from entering the pool, to preserve chemical treatments in the water and to heat the pool in the case of a solar cover. An automatic pool cover provides convenience for a user by allowing the cover to be easily extended over the pool during periods of non-use, and retracted during periods of use. Typically, a pool cover box is placed in or on the decking surrounding the swimming pool at a location opposite from the walk-in steps (i.e., usually located at the deep end of the pool). The pool cover box extends across the width of the swimming pool, and within the box is mounted a reel (which can be referred to as a drum) to store the pool cover on, an electric (or hydraulic) motor, and a mechanism to deploy and retract the pool cover.
A drive mechanism for driving the extension and retraction of the pool cover is known. Such a drive mechanism can be a spiral-jaw clutch system including a double driver member having a diagonal cam slot, an end member associated with a cover drum, and an end member associated with a reel. One problem with such a drive mechanism is that the double driver member must be mounted to a drive shaft in a specific orientation depending upon whether a motor-left or a motor-right orientation is used.
What is needed in the art is a drive device that selectively effects a positive engagement with a driven end members and that can be used as a universal drive device regardless of whether a motor-left or a motor-right orientation is used.
The present invention provides an engagement device with axial pins that engage holes in the driven end members, the engagement device configured for being mounted on a drive shaft in either direction and still being used with either a motor-left or a motor-right orientation.
The invention in one form is directed to a cover assembly for covering a container of liquid which includes: a drive shaft including a drive pin; an engagement device configured for moving axially on the drive shaft when the drive pin engages the engagement device, the engagement device including at least one first engagement mechanism; and a first engagement hub rotatably mounted to the drive shaft and configured for being driven by the engagement device, the first engagement hub including at least one second engagement mechanism which includes at least one magnet configured for pulling the at least one first engagement mechanism and thereby for facilitating an engagement of the at least one first engagement mechanism with said at least one second engagement mechanism.
The invention in another form is directed to a cover assembly for covering a container of liquid. The covering assembly includes: a drive shaft including a drive pin; a first engagement hub rotatably mounted to the drive shaft, the first engagement hub including a first hole; and an engagement device configured for moving axially on the drive shaft when the drive pin engages the engagement device, the engagement device including an axially extending first pin which is configured for engaging the first hole and thereby for driving the first engagement hub.
The invention in yet another form is directed to a method for using a cover assembly for covering a container of liquid which includes the steps of: providing a drive shaft, an engagement device, and a first engagement hub, the drive shaft including a drive pin, the first engagement hub being rotatably mounted to the drive shaft; moving axially the engagement device on the drive shaft when the drive pin engages the engagement device, the engagement device including at least one first engagement mechanism; driving, using the engagement device, the first engagement hub, the first engagement hub including at least one second engagement mechanism which includes at least one magnet; pulling, using the at least one magnet, the at least one first engagement mechanism and thereby facilitating an engagement of the at least one first engagement mechanism with the at least one second engagement mechanism.
An advantage of the present invention is it provides an apparatus for retracting and extending a pool cover over a swimming pool.
Another advantage is that it provides magnets in engagement holes so as to effect a positive engagement with corresponding pins, thereby providing a smooth engagement and disengagement of the pins from the holes.
Yet another advantage is that it provides an engagement device which can be used as a universal engagement device without regard to whether a motor-left or a motor-right orientation is used, the installer not having to orient the engagement device in any specific axial orientation on the drive shaft.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one embodiment of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and more particularly to
Deck 12 is generally horizontal and is preferably constructed from concrete. Coping 14 connects to deck 12 in a substantially coplanar fashion along the edge of deck 12 facing the interior of swimming pool 10.
Coping 14 is connected to deck 12 and provides a track allowing leading edge bar 18 to slide therein. The general shape of the exposed portion of coping 14 is generally curved such that there are no exposed sharp corners.
Cover 16 is attached to leading edge bar 18 which pulls cover 16 from pool cover box 20, through an opening existing between pool cover box 20 and a top edge of swimming pool 10, and across the length of swimming pool 10. To prepare swimming pool 10 for use, cover 16 retracts into pool cover box 20 pulling leading edge bar 18 to the previously described opening.
Leading edge bar 18 is connected to cover 16 and provides support along the leading edge of cover 16. Each end of leading edge bar 18 is connected to at least one cable, rope, or cord (rope being the term used herein but representing any such cable, rope, cord, or the like) and is slidably connected to a track in coping 14. Leading edge bar 18 is shaped in a manner to be unobtrusive and aesthetically pleasing when located at either end of swimming pool 10. Although coping 14 is shown as including an integral track for leading edge bar 18 and cover 16, it is also possible that a pair of top mounted tracks may be mounted to deck 12 along either side of swimming pool 10.
Pool cover 16, leading edge bar 18, and pool cover box 20 form part of a pool cover assembly 22, which also includes a reel 24 (which can be referred to as drum 24)(drum 24 is shown schematically in
A pulley bar 64 is inserted through holes in, and attached to, one bracket 34 by way of a pair of nuts 66 (for example, a Nylock nut). Four pulley spacers 68 (two of the same size) can be used on pulley bar 64. Three pulley assemblies 70 can be placed on pulley bar 64. Each pulley assembly 70 includes a pulley housing, a pulley screw (for example, a round head Phillips), and a pulley (for example, a double bearing) for a rope (the term “rope” is used herein and includes cables, cords, or the like). The pulley screw can be positioned in one of two through-holes in the pulley housing, through a corresponding hole of the pulley, and secured by a nut (for example, a Nylock nut, not shown) on the other side of the pulley housing;
Pool cover assembly 22 further includes two split bearing assemblies 80. Split bearing assemblies 80 are substantially identical to one another. Split bearing assembly 80 includes a split bearing 82 with a groove which seats within a U-shaped recess in bracket 30 to attach, at least in part, split bearing 82 to bracket 30. Split bearing assembly 80 further includes a plate secured to the bottom of split bearing 82 (on the side of the groove which is the thicker portion of split bearing 82), the plate being secured to split bearing 82 by way of a screw (for example, a round head Phillips). A pair of bolts (for example, with a hex head cap) extends upwardly from the plate (the bolt heads can be seated in a corresponding hole of plate), through split bearing 82, and out the top of split bearing 82, a corresponding compression spring and a nut (for example, a Nylock nut) being attached to the end of each bolt. Each compression spring is shown on top of the respective split bearing 82 in
Pool cover assembly 22 further includes drive shaft 28, rope reel 84, an end casting 86 of drum 24, a drive pin 88, sleeve 146, an engagement device 90, two engagement hubs 92, 94, and a bearing 96.
Drive shaft 28 extends on one end from motor coupling 54 to the opposing end in a hole in an end casting 86 of drum 24. Drive shaft 28 is rotatably driven by motor 26 by way of motor coupling 54. A bearing can be positioned between drive shaft 28 and the end casting 86 so that drive shaft 28 and drum 24 can rotate independently of one another. In this way, drive shaft 28 extends through both split bearing assemblies 80, rope reel 84, engagement hubs 92, 94, and engagement device 90. Drive shaft 28 can rotate independently of split bearing assemblies 80, rope reel 84, and engagement hubs 92, 94 and can, in part, rotate independently of engagement device 90 (until drive pin 88 completes its travel in slots 116, 118). At least one bearing 98 can be positioned between drive shaft 28 and rope reel 74, thereby facilitating the independent rotation of drive shaft 28 relative to rope reel 84. Drive shaft 28 can be considered to include drive pin 88. Drive shaft 28 can be made of stainless steel or any other suitable material.
Rope reel 84 includes reel section 76 and reel section 78, reel section 76 being attached to and capable of being wound by rope 72, reel section 78 being attached to and capable of being would by rope 74. Rope reel 84 can be a casting and can be made of stainless steel or any other suitable material. One end of rope reel 84 extends through the axial hole in one of the split bearings 82, can rotate relative to split bearing 82, and is thereby supported by this split bearing 82. The other end of rope reel 84 is attached to engagement hub 94. This can occur, for example, by using the four screws 100 (for example, with a socket head cap) or bolts 100 shown in
End casting 86 of drum 24 forms one end of drum 24. A reduced diameter portion of end casting 86 is inserted through the axial hole of split bearing 82. The longitudinal end face of end casting 86 has a central hole (shown in
Drive pin 88 is positioned within a through-hole 104 of drive shaft 28 (through-hole 104 being shown in
Sleeve 146 extends between split bearing 82 and rope reel 84. Sleeve 146 can be a clear plastic sleeve. More specifically, sleeve 146 can be a clear, semi-rigid, polyethylene tube with 2.05 inches inside diameter and 0.022 inches wall thickness; this material and these dimensions are provided by way of example and not by way of limitation. Components positioned within sleeve 146 include the following: engagement hub 92, engagement device 90, engagement hub 94, drive shaft 28, and drive pin 88. Drive pin 88 is in place on, and in contact with, drive shaft 28 by way of through-hole 104 in drive shaft 28. Drive pin 88 is free-floating relative to, with no press fit into, drive shaft 28 and is held in place in through-hole 104 by way of sleeve 146. Similarly, drive pin 88 is in place relative to, and in contact with, engagement device 90 by way of slots 116, 118 in engagement device 90. Drive pin 88 is free-floating relative to, with no press fit into, engagement device 90 and is held in place in slots 116, 118 by way of sleeve 146 through-hole 104. Sleeve 146 is shown in
Engagement device 90 can be referred to herein as an engagement dog 90. Engagement device 90 is configured for moving axially (in either direction, as shown by double-arrow 106) on drive shaft 28 when drive pin 88 engages engagement device 90. Engagement device 90 is configured for selectively driving each engagement hub 92, 94. Engagement dog 90 is generally formed as a cylinder and thus has a body 108 with a circular cross-section and two axial ends. Body 108 includes a centrally located axial through-hole 110 which receives drive shaft 28 therethrough. Each axial end includes two opposing blind holes 112 (positioned approximately 180 degrees apart on a respective axial end), which can, for example, be machined into the body 108. Further, each hole 112 is axially aligned with and axially opposes another hole 112 on the other axial end of body 108, as indicated by
As shown in
Engagement device 90 further includes a first pair of opposing slots 116 (which can be referred to as first pair of slots 116 or first slots 116) and a second pair of opposing slots 118 (which can be referred to as second pair of slots 118 or second slots 118) which are offset relative to first pair of opposing slots 116.
Adjacent ones of first pair of opposing slots 116 and second pair of opposing slots 118 converge toward one another. That is, first slots 116 are oriented relative to circumferential direction 120 (shown by arrow 120 in
Further, first pair of opposing slots 116 and second pair of opposing slots 118 selectively receive drive pin 88. That is, when inserting drive pin 88 in drive pin hole 104 on drive shaft 18, user (such as a pool cover installer or maintenance provider) can select whether to insert drive pin 88 in first pair of opposing slots 116 or second pair of opposing slots 118. If user chooses to insert drive pin 88 into first pair of opposing slots 116, then first pair of opposing slots 116 are aligned with drive pin hole 104 and drive pin 88 can be inserted through one first slot 116, then through drive pin hole 104, and then into the opposing first slot 116. Similarly, if user chooses to insert drive pin 88 into second pair of opposing slots 118, then second pair of opposing slots 118 are aligned with drive pin hole 104 and drive pin 88 can be inserted through one second slot 118, then through drive pin hole 104, and then into the opposing second slot 118. Drive pin 88 can be readily removed from drive pin hole 104 and first and second slots 116, 118.
A bearing 96 can be positioned between engagement dog 90 and drive shaft 28. Bearing 96 can, for example, be press fitted and/or adhered to central hole 110 of engagement dog 90. Alternatively, bearing 96 can be connected to engagement dog 90 and/or drive shaft 28 in any suitable manner. By way of example and not by way of limitation, bearing 96 can be a nylon sleeve (white ultra-high-molecular-weight). While bearing 96 is shown in
Engagement hub 92 is rotatably mounted to drive shaft 28 and is configured for being driven (that is, rotated in either direction on drive shaft 28, as indicated by double-arrow 142 in
Engagement hub 94 is rotatably mounted to drive shaft 28 opposite engagement hub 92 relative to engagement device 90. In other words, engagement hub 94 is on the other side of engagement dog 90 relative to engagement hub 92. Engagement hub 94 is configured for being driven (that is, rotated in either direction on drive shaft 28, as indicated by double-arrow 144 in
By way of example and not by way of limitation, engagement hubs 92 and 94 can be made of 316 stainless steel. By way of example and not by way of limitation, each engagement hub 92, 94 can be formed by casting, molding, machining, and/or any other suitable manufacturing method. With respect to drive pin 88, body 108 of engagement dog 90, engagement hubs 92, 94 (less magnets 126), magnets 126, and pins 114, magnets 126 and pins 114 are the only dissimilar metals. For illustrative purposes,
Magnets 126 effect a positive engagement between pins 114 and holes 124. Section 132 of each of pin hole 124 in engagement hubs 92 and 94 can be substantially identical. Pins 114 of engagement hubs 92, 94 can, according to one embodiment of the present invention, have the same diameter as the diameter of section 132 and have almost the same length as the length of section 132 (pin being 0.002 inch shorter)(these dimensions and relative dimensions are provided by way of example and not by way of limitation). Pins 114 are inserted into section 132 of pin holes 124. When pins 114 insert in respective pin holes 124, a secure fit between pins 114 and pin holes 124 is obtained. Further, the magnetic force of respective magnets 126 help to pull (attract) the corresponding pins 114 to the corresponding pin holes 124 and to pull the pins 114 into the pin holes 124 and thereby overcome any opposing frictional force because of the dimensions of the pin holes 124 and the pins 114. In this way, magnets 126 help pins 114 to seat fully within the corresponding pin holes 124. When engagement dog 90 is perfectly centered between the four magnets 126 (in the four pin holes 124) the magnetic force of attraction on the pins 114 is theoretically equal. In other words, neither side (on the side of engagement hub 94 or engagement hub 94) has more pull than the other. However, as engagement dog 90 begins to be moved in either direction axially along drive shaft 28 by drive pin 88, then pins 114 on that side (the side of the direction of movement) of engagement dog 90 will experience a stronger magnetic force of attraction and be further urged towards that respective engagement hub 92 or 94 (for example, engagement hub 92). At the same time, however, the magnets 126 from the other engagement hub 94 (the engagement hub away from which engagement dog 90 is moving, for example, engagement hub M 94) still exert an attractive force on engagement dog pins 114 (at least on those pins 114 which are facing engagement hub 94), this force thus still pulling on engagement dog 90 and thereby resisting the movement away from engagement hub 94. This resistive force helps to allow a smoother seating of pins 114 in the pin holes 124 of engagement hub 92 (to which engagement dog 90 is axially moving). Further, this resistive force (from the magnets 126 of engagement dog 94) also helps to unseat pins 114 from the pin holes 124 when drive shaft 28 changes direction of rotation and drive pin 88 begins to move engagement dog 90 axially away from engagement dog 90. The same type of forces of attraction and resistance are experienced by engagement dog 90 (in particular, the pins 114 of engagement dog 90) as engagement dog 90 moves back to a centered position and then onward to this engagement hub 94. In this way, the presence of magnets 126 mounted in pin holes 114 provides a “sureshift” of engagement dog 90 on drive shaft 28 towards a respective engagement hub 92 or 94. In summary, this magnet technology places magnets 126 into each of engagement hubs 92, 94 (these “ends” each being a single dog) directly lined up with pins 114 in engagement dog 90 (which can be referred to as a double dog); that is, pins 114 can be directly lined up with holes 124 of both engagement hubs 92, 94 when engagement dog 90 is on drive shaft 28. When shifting, engagement hub magnets 126 pull the tool steel pins 114 in engagement dog 90, thereby creating a resistance from both sides while drive pin 88 shifts and travels through its respective slot (116 or 118) until completion. The magnets 126 make the shift (that is, the shift of drive pin 88 in respective slots 116, 118 and also the shift (axial movement) of engagement dog 90 on drive shaft 28) more precise and smoother. Further, during installation, engagement dog 90 can be installed on drive shaft 28 relative to drive pin 88 so that pins 114 are directly lined up with pin holes 124, and engagement dog 90 can be positioned between engagement hubs 92, 94 so that axial movement of engagement dog 90 in either direction almost immediately moves respective pins 114 into respective pin holes 124. In this way, a centered position of engagement dog 90 between engagement hubs can mean that pins 114 are clear of holes 124 in both hubs 92, 94. Alternatively, a centered position of engagement dog 90 between hubs 92, 94 can mean that pins 114 are positioned partially in all four holes 124 (of both hubs 92, 94) and fully seating pins 114 in holes 124 of one hub 92 or 94 means that pins 114 are finally fully released from holes 124 of the other hub 92 or 94.
The present invention, according to one embodiment, thus provides a cover assembly 22 for covering a container 10 of liquid (such as swimming pool 10 containing water). Cover assembly 22 includes: drive shaft 28 including a drive pin 88; first engagement hub 92 rotatably mounted to drive shaft 28, first engagement hub 92 including a first hole 124; and engagement device 90 configured for moving axially on drive shaft 28 when drive pin 88 engages engagement device 90, engagement device 90 including an axially extending first pin 114 which is configured for engaging first hole 124 and thereby for driving first engagement hub 92. Cover assembly 22 further includes a second engagement hub 94 rotatably mounted to drive shaft 28 opposite first engagement hub 92 relative to engagement device 90, second engagement hub 94 including a second hole 124, engagement device 90 including an axially extending second pin 114 axially opposing first pin 114, second pin 114 being configured for engaging second hole 124 and thereby for driving second engagement hub 94. Engagement device 90 includes an additional first pin 114 which is substantially parallel to first pin 114, first engagement hub 92 including an additional first hole 124, additional first pin 114 being configured for engaging additional first hole 124 and thereby for driving first engagement hub 92. Engagement device 90 includes an additional second pin 114 which is substantially parallel to second pin 114, second engagement hub 94 including an additional second hole 124, additional second pin 114 being configured for engaging additional second hole 124 and thereby for driving second engagement hub 94.
In use, a reversible motor 26 can be used to turn drive shaft 28, and thereby drive pin 88, in either direction (clockwise or counter-clockwise direction). As drive pin 88 travels within a particular slot 116, 118 (being turned by drive shaft 28, which is powered by motor 26), drive pin 88 pushes on the longitudinal side of the slot 116 or 118 and thereby causes engagement dog 90 to slide along drive shaft 28 (by way of bearing 96) in one axial direction along the longitudinal axis (through central hole 110) of engagement dog 90 (given the angular orientation of each of the slots 116, 118 relative to circumferential direction arrow 120). When drive pin 88 reaches the end of a particular slot 116, 118 (thereby completing travel of drive pin 88 within the slot 116, 118), engagement pins 114 seat within corresponding holes 124 in one of engagement hubs 92 or 94. When drive pin 88 reaches the end of the slot 116 or 118, engagement dog 90 no longer moves axially on drive shaft 28 but can rotate with, and thus in the same direction as, drive shaft 28 as drive shaft 28 continues to rotate. Rotation of engagement dog 90 causes the corresponding engagement hub 92, 94 (the engagement hub 92 or 94 which engagement dog 90 is engaging with respective engagement pins 114) to rotate. Rotation of engagement hub 92 or 94 causes either drum 24 or rope reel 84, depending upon which engagement hub 92 or 94 is engaged by engagement dog 90, to rotate. Conversely, when drive shaft 28 is reversed in its direction of rotation (by reversing the motor), then drive pin 88 is rotated and moved from one end of the slot 116 or 118 to the other end of the slot 116 or 118. As drive pin 88 travels through the slot 116 or 118, drive pin 88 pushes on another longitudinal side of the slot 116 or 118 and thereby causes engagement dog 90 to slide along drive shaft 28 (by way of bearing 96) in an opposite axial direction. When drive pin 88 reaches the end of that particular slot 116 or 118 (thereby completing travel of drive pin 88 within that slot 116 or 118), the engagement pins 114 of the other axial end of engagement dog 90 seat within corresponding holes 124 of the other engagement hub 92 or 94 (the engagement pins 114 from the opposing axial end having been released from the opposing engagement hub 92 or 94). When drive pin 88 reaches that end of the slot 116 or 118, engagement dog 90 no longer moves axially on drive shaft 28 but can rotate with drive shaft 28. Rotation of engagement dog 90 causes the corresponding engagement hub 92 or 94 to rotate. Rotation of engagement hub 92 or 94 causes the other of either drum 24 or rope reel 84 to rotate. Thus, if drive pin 88 is positioned in hole 116 in
During installation, the installer can choose a motor-left or a motor-right orientation for the pool covering assembly 22. In a motor-left orientation, (from one perspective) motor 26 is placed at the left side of swimming pool 10 in pool cover box 20; conversely, in a motor-right orientation, (from one perspective) motor 26 is placed at the right side of swimming pool 10 in pool cover box 20. Whether one uses a motor-left orientation or a motor-right orientation can be used to determine whether drive pin 88 is positioned in first pair of slots 116 or second pair of slots 118. For example, if one considers the view shown in
Advantageously, however, when switching between a motor-left and a motor-right orientation (or vice versa), drive pin 88 can simply be moved from one pair of slots 116 or 118 to the other pair of slots 116 or 118 and thereby avoid any confusion of the end-user with regard to which direction the motor 26 will move the cover 16 when turning the motor 26 on “forward” or “reverse” (or, “retraction” or “extension”, or the like). In this way, the motor retraction switch and the motor extension switch remain oriented the same, with respect to an end-user, and the same motor 26 can be used for a motor-left and a motor-right orientation, regardless of whether a motor-left or a motor-right orientation is used. Slots 116, 118 are thus placed ninety degrees from one another to allow switching of the placement of drive pin 88 relative to engagement dog 90. Selection of one slot 116 or 118 versus the other thus allows engagement dog 90 to be used universally as a motor-right or a motor-left mechanism.
The present invention further provides a method for using a cover assembly 22 for covering a container 10 of liquid. The method includes the steps of: providing a drive shaft 28, an engagement device 90, and a first engagement hub 92, drive shaft 28 including a drive pin 88, first engagement hub 92 being rotatably mounted to drive shaft 28; moving axially engagement device 90 on drive shaft 28 when drive pin 88 engages engagement device 90, engagement device 90 including at least one first engagement mechanism 114; driving, using engagement device 90, first engagement hub 92, first engagement hub 92 including at least one second engagement mechanism 124 which includes at least one magnet 126; pulling, using at least one magnet 126, at least one first engagement mechanism 114 and thereby facilitating an engagement of at least one first engagement mechanism 114 with at least one second engagement mechanism 124. Engagement device 90 includes an additional first engagement mechanism 114 axially opposing first engagement mechanism 114, the cover assembly 22 further including a second engagement hub 94 rotatably mounted to drive shaft 28 opposite first engagement hub 92 relative to engagement device 90, the method further including driving, using engagement device 90, second engagement hub 94, first engagement hub 92 including at least one second engagement mechanism 124 which includes at least one magnet 126, the method further including pulling, using at least one magnet 126 of at least one second engagement mechanism 124 of second engagement hub 94, the additional first engagement mechanism 114 and thereby facilitating an engagement of the additional first engagement mechanism 114 with at least one second engagement mechanism 124 of second engagement hub 94. Each first engagement mechanism 114 is a pin 114 and second engagement mechanism 124 is a hole 124. Engagement device 90 includes a first pair of opposing slots 116 and a second pair of opposing slots 118 which are offset relative to first pair of opposing slots 116, first pair of opposing slots 116 and second pair of opposing slots 118 selectively receiving drive pin 88. First pair of opposing slots 116 are offset approximately ninety degrees relative to second pair of opposing slots 118. Adjacent ones of first pair of opposing slots 116 and second pair of opposing slots 118 converge toward one another.
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
3050743 | Lamb | Aug 1962 | A |
4686717 | MacDonald | Aug 1987 | A |
4811433 | MacDonald | Mar 1989 | A |
4815152 | MacDonald | Mar 1989 | A |
4858253 | Lamb | Aug 1989 | A |
5044022 | Hess | Sep 1991 | A |
5105481 | Lamb et al. | Apr 1992 | A |
5524302 | Ragsdale | Jun 1996 | A |
5913613 | Ragsdale | Jun 1999 | A |
5920922 | Ragsdale | Jul 1999 | A |
6431488 | Zemla | Aug 2002 | B1 |
8418280 | Schwerzmann | Apr 2013 | B2 |
20070256230 | Phizackerley | Nov 2007 | A1 |
20080135579 | Bertram | Jun 2008 | A1 |
20100018825 | Claeys | Jan 2010 | A1 |
20100199417 | Shebek | Aug 2010 | A1 |
20140000021 | Scheps | Jan 2014 | A1 |
Number | Date | Country | |
---|---|---|---|
20150096115 A1 | Apr 2015 | US |