various aspects of the present disclosure generally address one or more of the problems related to the operation of a glider chair . more particularly , aspects of the present disclosure address problems related to the operation of a glider armchair providing backrest reclining and footrest deployment ( extension ) functions . operation of the backrest / footrest functionalities of the glider armchair , without preventing gliding motion , is further addressed . an embodiment of a gliding mechanism for a gliding recliner chair and of a gliding recliner armchair with footrest comprising the gliding mechanism , will now be described in details referring to the appended drawings . however , at least some of the teachings of the present disclosure are applicable to glider chairs without armrest and / or without footrest . the following description of a gliding recliner armchair with footrest is illustrative only and is not intended to limit the applicability of the gliding mechanism to other types of glider chairs . referring to fig7 a - 7 e , there is illustrated a gliding recliner armchair 100 comprising a seat 10 and backrest 12 assembly mounted on a pair of parallel spaced apart pantographic backrest / footrest actuators 40 a - 40 b assembled on a cross member 22 extending between and connecting first 20 a and second 20 b vertical side frames together to form a seating assembly . the actuators 40 a - 40 b enable reclining movement of the backrest synchronized with seat displacement with respect to frames 20 a - 20 b and extension of a footrest plate 41 ( see fig1 to 6 ). upper portions 21 a - 21 b of the frames 20 a - 20 b can be used as armrests . alternatively , separate padded armrest members ( not shown ) can be mounted to the upper portions 21 a - 21 b , using screws for example . of course , a glider chair using the present gliding mechanism may be provided without armrests . each of side frames 20 a - 20 b is operatively connected to a floor - standing base 50 . connection of the floor - standing base 50 to the side frames 20 a - 20 b is made through connecting links 30 a - 30 d . bolts or studs 33 a - 33 d attach the connecting links 30 a - 30 d to the side frames 20 a - 20 b and bolts or studs 34 a - 34 b attach the connecting links 30 a - 30 d to the floor standing base 50 . more specifically , the connecting links 30 b and 30 d connect a front portion of the floor - standing base 50 to front portions of the side frames 20 a - 20 b using bolts or studs 33 b , 33 d , 34 b and 34 d . likewise , the connecting links 30 a and 30 c connect a back portion of the floor - standing base 50 to back portions of the side frames 20 a - 20 b using bolts or studs 33 a , 33 c , 34 a and 34 c . the bolts or studs 33 a - 33 d and 34 a - 34 d are configured to allow pivoting of the connecting links 30 a - 30 d , in order to enable gliding movement of the seating assembly with respect to the floor - standing base 50 , as it is known in existing glider armchairs . for example a front pivoting point p 1 is formed by bolt or stud 33 b and a back pivoting point p 2 is formed by bolt or stud 34 a . front links 30 b and 30 d are transversely connected together by a rod 31 and links 30 a and 30 c are transversely connected together by a rod 32 to ensure coordinated movement . the floor - standing base 50 comprises a pivoting portion 51 ( fig9 a - 9 d ) assembled on a circular floor - engaging portion 58 for pivotal movement about a vertical axis 56 . referring more specifically to fig9 a - 9 d , the pivoting portion 51 comprises a longitudinal cross member 53 connected at each end to braces 55 a - 55 b so that the cross member 53 is parallel to a width of the pivoting portion 51 and with a width of the seating assembly . a center post , or pivot 52 , is mounted on the cross member 53 for pivotally engaging a bore 57 and bushing ( not shown ) provided at the center of the floor - engaging portion 58 at the axis 56 , which is perpendicular to the plane of a perimeter 59 of the floor - engaging portion 58 . the symmetry of the perimeter 59 allows the armchair 100 to recline and glide in any radial orientation of the seating assembly in relation to the floor - engaging portion 58 . in an alternative embodiment of the gliding recliner armchair 100 , a circular rotation of the seating assembly about the axis 56 may not be provided . in this alternative embodiment , the pivoting portion 51 is fixedly connected to the floor - engaging portion 58 . unlike known gliding armchairs , links 30 a - 30 d are mounted on the inside of the pivoting portion 51 but outside of the pantographic actuators ( between the actuators 40 a - 40 b and the pivoting portion 51 ). this special feature enables the use of a relatively wider and more comfortable footrest plate 41 extending between the side frames 20 a - 20 b without interfering with the floor - standing base 50 during gliding when the footrest actuators 40 a - 40 b are retracted . at least one stop pin 54 ( here , one is provided on each side ) is provided to define a backmost position of gliding when links 30 b and 30 d abut thereon . contact of links 30 a - 30 b with cross member 53 acting as a stop member defines the foremost allowed position of gliding . referring to fig1 a and 1 b , the armchair 100 is shown with a user in a sitting position and with the actuators 40 a - 40 b extended to provide reclined backrest 12 and deployed footrest 41 . a representative user selected for stability studies was 6 foot tall and weighed about 180 pounds . in fig1 a , the armchair is shown in a foremost position of the gliding movement and in fig1 b the armchair in shown in a rearmost position of the gliding movement . vertical phantom lines are provided : line c showing the center axis of the pivot 52 and bore 57 supporting the pivoting portion 51 , line pb being a normal projection of the backmost end of the perimeter 59 of the floor - engaging portion 58 , and line pf being a normal projection of the foremost end of the perimeter 59 . fig2 a and 2 b represent the same respective armchair positions but with a partial view to better show a path 90 followed by the center of gravity during gliding . gf indicates the instant position of the center of gravity in the position of fig1 a ( foremost ) and gb indicates the instant position of the center of gravity in the position of fig1 b ( backmost ). as can be appreciated , the present design limits displacement of the center of gravity of the present gliding recliner armchair in the most extreme conditions , i . e . reclined backrest 12 and deployed footrest 41 . a center 91 of the path 90 followed by the center of gravity is substantially normal to the vertical axis 56 of the floor - standing base 50 . by reducing the displacement of the center of gravity along the path 90 in proximity with the vertical axis 56 of the floor - standing base 50 , it is possible to provide a gliding recliner armchair with a reclinable backrest , and deployed footrest , which can be safely glided in its fully open position . fig2 a and 2 b further show that at any particular gliding position , the projection of the combined center of gravity along an axis normal to the plane of the perimeter 59 always falls within the perimeter delimited by lines pf and pb . moreover , one may observe that the projections of gf and gb in these critical positions are still away from pf or pb by a ratio of about ⅓ of a dimension l corresponding to the base perimeter ( substantially equal to the diameter of floor - engaging portion 58 ). given the symmetry of the floor - engaging portion 58 , this holds true for any angular position of the armchair about the central axis c . a ratio higher than about 20 % has been found by experience to provide sufficient stability . therefore , it can be seen that the cross member 53 supporting the upper portion of the armchair 100 on the floor - engaging portion 58 is not centered between the front and back pivoting points ( for example p 1 and p 2 on fig9 d ) of links 30 on the pivoting portion 51 but is rather strategically positioned rearward to enable a stable and safe behavior of gliding movement in reclined and footrest extended position with respect to the center of gravity . on fig9 d , a horizontal distance d 1 between the front pivoting point p 1 and the vertical axis 56 is about 1 . 85 times a horizontal distance d 2 between the vertical axis 56 and the back pivoting point p 2 . this relation between values of d 1 and d 2 is illustrative and non - limiting . some variations of a ratio of d 1 over d 2 are contemplated . for example d 1 can be greater than d 2 by a factor in a range between about 1 . 6 and 2 . in one practical and non - limiting realization , the floor - engaging portion 58 has a base perimeter l equal to 26 inches while the seat 10 has a depth of 20 inches . on fig7 a , which shows the gliding recliner armchair unloaded ( without user ) with the backrest and footrest in fully retracted position , a front edge of the seat 10 extends beyond the diameter of the floor - engaging portion 58 by about one ( 1 ) inch and a rear edge of the seat 10 lies within the diameter of the floor - engaging portion 58 by about seven ( 7 ) inches . consequently , the seat 10 is centered longitudinally about four ( 4 ) inches forward in relation to the vertical axis 56 . workable values of the ratio of d 1 over d 2 , the sizes of the floor - engaging portion 58 and of the seat 10 , and relative positions of the seat 10 and of the floor - engaging portion 58 are expected to vary according to selected dimensions of various components of the gliding mechanism and of the gliding recliner seating assembly , and according to the intended use of the gliding mechanism and of the gliding recliner seating assembly . fig3 a and 3 b show the gliding recliner armchair with only the footrest extended in respectively the most frontward and rearward positions . as depicted , at the most frontward and rearward gliding positions , the center of gravity of the armchair with the footrest extended remains within slightly less extremes and safer limits than the displacement represented in fig2 a - 2 b previously discussed . the reduced movement of the gravity center indicates that the presence of a user has minimal influence on the stability in this situation , and that geometric properties and material selection of the armchair 100 would hold safe operation for a very wide range of anthropometric characteristics . steel or any material with similar solidity characteristics is selected for adequate rigidity of the armchair structure and for proper balancing . of course , this does not apply to cushioning , to seat and backrest suspension or to cosmetic make up . fig4 a - 4 b and 5 a - 5 b show that stability is also kept within a similar safety range when the footrest 41 and backrest 12 are set in the retracted position , with or without a user sitting . actually , the most critical position a user may experience is with the footrest 41 retracted when reaching the foremost gliding position . still , in the stability studies for the 6 foot tall , 180 pounds representative user , the projection of gf in fig4 a remained inside the perimeter 59 and away from line pf by about 17 % of l , as illustrated on fig4 a . this situation is considered acceptable by experience considering that forward tilting of the armchair doesn &# 39 ; t occur without excessive forward projection of the user &# 39 ; s body and the user may easily put his feet on the floor and stand up from the sitting position . it is envisioned that any projection of gf at least 15 % away from line pf provides safe operation of the gliding recliner . therefore , the built - in safety factor is higher for the extended position and backmost gliding attitude since backward tilting theoretically presents a higher risk of injury . the difference between the resting position of the armchair 100 , with backrest 12 and footrest 41 in ( a ) a fully retracted position and ( b ) a fully extended position is shown at fig6 a and 6 b . it can be seen that the reclining actuators 40 a - 40 b do not change the relative angle between the seat 10 and the backrest 12 , but cause this seat 10 and backrest 12 assembly to slide and tilt in the backward direction . a user may perform the displacement from retracted position to reclined position , simply by urging his back against the backrest while pushing forward on the frames 20 a - 20 b and unfolding his legs . at rest , in either position , the center of gravity is very close to the center axis c of the pivot 52 and naturally slightly forward in the reclined position . one may therefore appreciate that the afore described embodiment of the gliding recliner armchair with footrest provides a safe , reliable and cost effective way of enabling gliding and backrest reclining / footrest deployment operable simultaneously in a same piece of furniture . therefore , it can be seen that the armchair according to the present disclosure overcomes the limitations , drawbacks and shortcomings of existing gliding recliners . although the present gliding mechanism has been described hereinabove by way of non - restrictive , illustrative embodiments thereof , these embodiments may be modified at will within the scope of the appended claims without departing from the spirit and nature of the present disclosure .
a gliding mechanism for a gliding recliner seating assembly comprises a floor - standing base having a longitudinal cross member parallel to a width of the seating assembly . two front connecting links and two back connecting links respectively connect , pivotally , front and back portions of the seating assembly to the floor - standing base . the longitudinal cross member supports a weight transferred by the seating assembly to the floor - standing base and is positioned closer to the back portion of the seating assembly than to the front portion of the seating assembly . the gliding mechanism can be made part of a gliding recliner chair , for example an armchair , having vertical side frames pivotally connected to the floor - standing base . a footrest can be added to the seating assembly and be operated in extended position without preventing gliding movement of the chair . the floor - standing base may comprise a pivoting portion allowing rotation of the chair .