in the following descriptions , the present invention will be explained with reference to various example embodiments ; nevertheless , these example embodiments are not intended to limit the present invention to any specific example , embodiment , environment , application , or particular implementation described herein . therefore , descriptions of these example embodiments are only provided for purpose of illustration rather than to limit the present invention . the invention is to cover all modifications , equivalents , and alternatives falling within the scope of the invention as defined by the appended claims . referring to fig1 and fig2 , a knee pad assembly 100 is shown . the assembly generally comprises a base 102 and a removable cover 104 . the base 102 fastens to the user &# 39 ; s knee using fastening straps 106 , such as the ratcheting adjustable straps as shown in these figures with ratcheted fastener 109 . an upper and a lower strap are shown but more or fewer straps are within the scope of the invention . the base 102 presents a forward facing cover receiving portion 108 . the cover 104 is disposed over the forward facing portion 108 of base 102 as indicated in these figures and secured via attachment means , in this example via corner hooks 110 disposed at the corners of base 102 . the assembled knee pad 100 is shown in fig2 . the knee pad base can be configured in short or long versions as appropriate for the particular application and a user &# 39 ; s desired level of coverage . the cover is correspondingly sized . the cover may be formed from any suitable material , including rubber and plastic , and formed in any suitable shape . in addition , the cover may fully or partially comprise multirole materials such as leather , cloth , plastic , fiber glass , foam , rubber , carbon fiber , composites , metal or any other material that is designed for the end user &# 39 ; s specific job requirements . a wide variety of cover attachments means are within the scope of the invention . such means include , but are not limited to hooks , snaps , clips , hook and loop components ( e . g . velcro fasteners ) on respective portions of the base and cover , and combinations of two or more different attachment means . the user &# 39 ; s ability to change covers on the knee pad bases allows for a single pair of knee pads to be adapted to a wide variety of surface types . the ability to change covers also provides the user with the option to replace individual worn covers , wash soiled covers , and / or use job specific covers as needed , avoiding the need to purchase a replacement or additional set of knee pads . referring to fig3 and 4 , another example embodiment of a knee pad assembly 200 is shown . the base 202 is provided with one or more front facing suspension components 212 , such as rubber or foam pads . in this example embodiment , base 202 is slideably engaged with pad 204 by straps 214 that are integrated into the corners of pad 204 . straps 214 secure the knee pad assembly 200 to a user by wrapping straps 214 securely around the back of the users knee . it should also be noted that straps 214 could also be integrated with base 202 and slide through corresponding openings ( not shown ) in pad 204 to also achieve the floating suspension effect . cords may also be used instead of straps . while secured , the back surface of pad 204 engages the suspension member 212 of base 202 , and slides on guide rails 216 , allowing pad 204 to float on suspension member 212 and remain aligned via guide rails 216 , without being fixably connected to base 202 . this allows pad 204 to move in toward the knee and out away from the knee , depending on the pressure exerted on the front surface of pad 204 while in use . this provides cushioned suspension for the knee while the improved knee pad assembly is in use . the spring force of the compression component 212 may be adapted to a desired range of cushioning or compression based upon a user &# 39 ; s weight , and / or the conditions of use of the knee pad , and / or the length of time of intended use . preferably a material with an ild ( indention load deflection ) of between 45 and 100 may be used . urethane and other foams may also be used with densities of weights between 1 and 10 pounds per square foot of material . the outer cover 204 may comprise a semi - rigid or a hard plastic shell ( or similar material ) that will compress one or more of the suspension components 212 and distribute the force over the cover 204 . the cover 204 cooperates with a plurality of integrated straps 214 , guide rails 216 and guide plate 218 to facilitate slideable engagement , and uniform alignment , of the cover to the base . this example embodiment also illustrates a tension / release mechanism or feature . when kneeling , compression placed on the cap 204 would compress suspension components 212 and release strap tension on straps 214 and when standing , compression would be released and strap tension would be allowed to return . the purpose is to release strap tension on the back of the worker &# 39 ; s leg , nerves and blood vessels while the worker is kneeling , yet maintain security of the knee pad when the worker is standing or walking . the cap 204 , straps 214 , suspension components 212 , guide rails 216 and guide plate 218 cooperate to achieve this feature , as well as providing a uniform alignment of the cap 204 with the base 202 , and providing extended comfort to the user . referring to fig5 and 6 , another embodiment of a knee pad assembly 300 is shown . the base 302 comprises a knee cup 304 and a suspension member 306 disposed on the outer front surface of the base . an outer cover or shell 308 is disposed over knee cup 304 and suspension member 306 by straps 310 . this arrangement allows force applied to the cover to compress the collapsible or suspension member towards the base to provide cushioning . the edges of the cover 308 slide toward the user &# 39 ; s knee along the outer perimeter surface of the base . when the pressure on the cover is released , the suspension member 306 expands to its original shape . in one variant , the suspension member 306 is partially collapsible in order to provide adequate support and air space while collapsible enough to provide desired cushioning . in addition open areas 312 in suspension member 306 allow additional cushioning and support for the knee . similar to the embodiments described and depicted in fig3 and 4 , the contact and cooperation between cover or shell 308 and suspension member 306 provides a floating type suspension for the knee while the knee pad 300 is strapped to a user by straps 310 . referring to fig7 , depicted is yet another exemplary embodiment where knee pad assembly 400 is comprised of base 402 , which is a partial shell that is disposed behind the user &# 39 ; s leg , such as on the calf and behind the knee , and cap 404 . for example , straps or a neoprene back of leg wrap 402 may be substituted for the base and straps described in the preceding examples . the cover 404 is then placed over the knee cap and restrained in place via tension members 418 , such as cords , on either side of the base spanning between the base and the cover . this arrangement promotes good pressure management on the user &# 39 ; s knee and leg . the cover 404 is shown with a honeycomb pattern 420 in a soft rubber material in order to enhance traction and provide cushioning for the user . a further feature illustrated in this example is the ratchet system 422 disposed on top of cover structure 404 and functionally connected to the tension members 418 . via the ratchet system 422 , the wearer has the ability to tighten or loosen strap pressure ( snugness ) of the knee pad . a dial 424 or other user actuator is provided to allow the user to actuate the ratchet system . referring to fig8 through 15 , depicted are various means to removeably attach a pad to a base . fig8 provides a base 502 with one or more sleeves or pockets 504 to receive the tongues 508 of cover 506 . the front receiving surface 510 of the base 502 and back surface 511 of cover 506 , may further be provided with a respective portion of a hook and loop fastener 512 to further secure the cover to the base . the cover 506 shown in this example is a generally rectangular and slightly curved semi - rigid board comprising a polyethylene material . however , the board can vary in size , shape and material as appropriate for the particular usage . referring to fig9 , an exemplar knee pad assembly is shown with another cover fastening means . an elastic hem 522 is provided around the perimeter 524 of the cover receiving surface 526 of the base 520 . the perimeter 528 of the cover 530 includes corresponding protruding tabs or projections 532 that are sized and shaped for being received in the elastic hem 522 . hook and loop 527 may also be used as shown in fig8 , and can further be used with all embodiment disclosed herein . referring to fig1 , a further embodiment of a knee pad assembly is shown . the base and cover is shown in fig9 . in addition , an overlay cover 534 is now provided . the overlay cover 534 is disposed over the cover 530 and then secured to the base with a plurality of reinforced strap loops 536 . the straps 538 used to secure the base to the knee region of the user are placed through the reinforced loops 536 of the overlay cover 534 to secure the cover and overlay in place . referring to fig1 , another embodiment of a knee pad assembly is shown . the cover or overlay 540 includes a plurality of elastic bands or cords 542 . the cords 542 can extend through the cover 540 for better securement . a tab 544 is provided at an approximate mid - point of each band 542 . the cover 540 is secured to the base 546 by inserting the tabs 544 into respective slots or pockets 548 in the base 546 . channels 550 in the outer perimeter surface 552 of the base 546 may be provided to further retain the bands in place . hook and loop fasteners 554 may further be provided on respective portions of the cover and base to further secure the cover to the base . fig1 illustrates a cord - lock means 562 for securing the cover 564 to the base 566 . raised corners 568 on the cover are inserted behind portions of the locking cord 570 . the locking cord or cords 570 are then tightened by pulling on cords 563 and retainer 562 is then used to maintain the tension in the retaining cord ( s ). fig1 through 15 illustrate other exemplar attachment embodiment means for a knee pad assembly . the cover or overlay 578 includes a plurality of elastic bands or cords 572 shown at the corners of the cover 578 . the cords can extend through the cover in a crossing pattern or “ x ” shape 574 for better securement , as shown in fig1 . a tab 576 is provided at an approximate mid - point of each band 572 . the cover 578 is secured to the base 580 by inserting the tabs 576 into respective slots or pockets 582 in the base at the corners thereof . the corner pockets may be raised to facilitate insertion and removal of the tabs . fig1 further illustrates that cover 578 may be used to secure pads used in previous embodiments to a base such as base 580 . note that the underlayment of pad 584 of fig1 includes a plurality of slots 586 for receiving the knee pad retaining straps 581 . the compressibility factor ( including material property and physical dimensions and shape ) of the collapsible or suspension members disclosed herein can be varied to accommodate different user weight ranges and to accommodate a user &# 39 ; s desired cushioning factor . the cover can be secured using a variety of means as discussed in this disclosure . alternatively , the cover may include straps that secure the assembly directly to the user &# 39 ; s knees , such as elastic cord or adjustable straps that extend behind the knee of the user . the collapsible or suspension members may comprise a wide variety of materials , including , springs , pen cell foam , closed cell foam , air bag , molded eva , soft 3d fabric ( spacer mesh ), a resilient honeycomb structure , rubber , or any combination of these or other materials . the cushioning factor can also be selected according to body weight or according to average time spent kneeling / hour . for example , body weight ranges of 80 to 150 lb , 150 to 225 lb , and over 225 lb ; kneeling 10 min ./ hour , 30 min ./ hour and 50 min ./ hour . however more or fewer ranges may be specified . features of the various embodiments discussed herein can be mixed and matched in any manner of additional embodiments that are all within the scope of the invention regardless of whether or not explicitly discussed herein . while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments , it will be apparent to those of ordinary skill in the art that the invention is not to be limited to the disclosed embodiments . it will be readily apparent to those of ordinary skill in the art that many modifications and equivalent arrangements can be made thereof without departing from the spirit and scope of the present disclosure , such scope to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and products . moreover , features or aspects of various example embodiments may be mixed and matched ( even if such combination is not explicitly described herein ) without departing from the scope of the invention . for purposes of interpreting the claims for the present invention , it is expressly intended that the provisions of section 112 , sixth paragraph of 35 u . s . c . are not to be invoked unless the specific terms “ means for ” or “ step for ” are recited in a claim .
disclosed are knee pad assemblies , methods and systems comprising a knee pad base and an outer cover that forms the contacting surface of the knee pad . a removable cover may be secured to a knee pad base . replacement cover configurations may be provided that are adapted to various surfaces , including roofing , tile , wood , carpet , concrete and asphalt . the knee pad base can be adapted for different user weights and durations for wearing the pad . the outer cover can provide a floating suspension . the knee pad base may be held in place on knee of the user by various mechanisms . the restraint mechanisms can be adjusted by the user . the knee pad assembly can also include a tension / release mechanism so that strap tension is decreased or released when kneeling but increases tension or engage when the user stands to retain the knee pad in the desired location .