Abstract:
A bench for a vehicle is provided, which bench comprises at least two seats that are arranged next to one another and are connected to one another. Provision is made for one of the at least two seats to act as a base seat that has at least one locking unit for the purpose of connection to a vehicle floor of a vehicle body, while the at least one other seat hovers above a vehicle floor since the other seat is reversibly connected solely to the base seat.

Description:
This nonprovisional application is a continuation of International Application No. PCT/EP2012/000197, which was filed on Jan. 18, 2012, and which claims priority to German Patent Application No. 10 2011 010 387.2, which was filed in Germany on Feb. 5, 2011, and which are both herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a seat bench which enables a variable seat arrangement in a vehicle. 
     2. Description of the Background Art 
     Variable seat concepts with a predetermined seat arrangement are known from the prior art; these allow a number of seat combinations in terms of the number of passengers or the use of the seats. 
     In some seat concepts, the main focus in terms of variability is that the trunk compartment conditions can be flexibly adjusted. 
     In other known seat concepts, the main focus is to be able to transport as many people as possible. Thus, in a known seat concept in the maximum variant there is room for up to eight passengers plus the driver in a vehicle: in each case, three passengers in the two three-seat rows of the second and third row of seats in the rear and two persons in the optional front passenger two-seat bench and the driver in a single seat. The second row of seats behind the driver or the front passenger two-seat bench or the front passenger single seat has, for example, a foldable two-seat bench with backrest adjustment plus a single seat with an “easy entry” folding mechanism for easier side entry. In comfort versions, all single and double seats can be folded down, folded flat, and removed. 
     In all known seat concepts, the focus is always on two viewpoints for reasons of comfort. On the one hand, it must be assured that the weight of the single and/or double seats is not too great particularly for removal and installation or for the so-called rolling up of the vehicle seat or the folding down of the backrest. In practice, even the single seats are usually so heavy that they can be removed or rolled up only by strong individuals. On the other hand, the unlocking and locking of the single and/or double seats for their removal and installation or for rolling up the vehicle seat or for folding down of the backrest must be easily achieved and actuated. The removal and installation, the rolling up of the car seat, or the folding down of the backrest should be rapidly executable, whereby the body-side connection of the single and/or double seats must be so secure, however, that they remain secure in a crash and moreover it is assured that the crash forces are safely conducted away into the body of the vehicle. 
     A seat unit with two or more passenger seats, which have rapid-release fastening devices, by means of which a common base device can be connected to a passenger seat or a plurality of passenger seats, is known from DE 42 39 141 A1. The passenger seats in the known approach, however, are not optimally designed in terms of their weight. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a variable seat concept, which allows variable seat combinations and in addition can be handled comfortably and rapidly. 
     In an embodiment a seat bench for a vehicle is provided, which bench comprises at least two seats, which are arranged next to one another and are connected to one another. 
     It is provided that one of the at least two seats acts as a base seat, which has at least one locking unit for connection to a vehicle floor of a vehicle body, whereas the at least one other seat (side seat) floats above a vehicle floor, because the other seat (side seat) is reversibly connected solely to the base seat. 
     In an embodiment of the invention, the base seat is always the middle seat and the at least one other seat is a side seat, which is arranged to the left and right or to the right and left of the middle base seat. 
     In an embodiment of the invention, it is provided that to form a two-seat bench a side seat is arranged beside the middle base seat and to form a three-seat bench two side seats are arranged, said seats being connected in a floating manner to the middle base seat. 
     An object that a change in the seat arrangement is possible variably, whereby primarily the weight of the side seat is reduced by the reduced understructure, is attained by the floating arrangement of the side seats. To assure rapid and comfortable handling during the installation and removal of the side seats, advantageous simple fastening variants for connecting the side seats with the middle base seat have been created. 
     In a first fastening variant, the connection between the base seat and the at least one side seat occurs in that the base seat has at least one receiving element in which an adapter plate of the at least one side seat can be fastened. 
     In a second fastening variant, the connection between the base seat and the at least one side seat occurs in that the base seat has a joint arrangement to which at least one frame of the at least one side seat can be fastened. 
     In a third simplified fastening variant, it is ensured in a basic version that the connection between the base seat with the at least one side seat occurs in that a screw-type module is arranged between the base seat and the at least one side seat. 
     In an embodiment of the invention, to increase the variability the possibility is created to change a two-seat or a three-seat bench into a rolled-up position, whereby in a starting position the seat benches are connected via four attachment points with a vehicle floor of a vehicle body and during the rolling-up process, which is described extensively in the description part, are connected to the vehicle floor only via two attachment points. 
     In an embodiment of the invention, to increase the variability further, the possibility is created that the side seats, particularly the seat bench of the second row of seats, can be changed into an easy-entry folded position, which is described extensively in the description section. 
     The design of the seat bench and the variable options are combined with the idea that both the side seats and the middle base seat are produced in a lightweight manner. The side seats in particular, which are installed and removed more often in practice, are produced almost entirely from a lightweight material. It is also provided, however, to produce the base seat from a lightweight material, whereby some components of the seat structure are produced from a steel material, to assure that crash forces, acting on the base seat and the side seat in a crash, are absorbed and can be conducted to the vehicle body. The lightweight concept is also explained in greater detail in the description section. 
     Such a seat bench is arranged on a vehicle body of a vehicle, in which the vehicle body according to the invention has a maximum of four body-side attachment points for connecting the seat bench with up to three seat places in a row of seats, whereby the reversible connection of the seat bench to the vehicle floor is assured via the attachment points together with the locking units of a base seat of the seat bench. The seat arrangement is characterized particularly in that at least one side seat, which is arranged at the middle base seat, floats above the vehicle floor of the vehicle. 
     The vehicle of the invention is characterized in that the vehicle floor of the vehicle body has only four attachment points for mounting a two-seat or a three-seat bench in a row of seats. 
     If two seat benches (two-seat or three-seat) are arranged in two rows of seats, the vehicle has only eight attachment points. 
     It therefore applies in general depending on the number n of the rows of seats n=1, n=2 for a first or a first and a second row of seats that the number of attachment points is in each case four times the number of rows of seats, whereby a row of seats comprises at least one base seat and one other seat (left or right) or two other seats (left and right). 
     Finally, in a further embodiment it is proposed that the four feet of a seat bench of a row of seats can be fastened slidably via a rail system, which preferably is provided in the lengthwise direction of the vehicle on the vehicle floor. The attachment points in this embodiment are not arranged unchangeable on the vehicle floor, but it is possible in an advantageous manner to move the seat bench flexibly within the vehicle relative to the body, further to the front or further to the back in the vehicle, on the rails of the rail system. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein: 
         FIG. 1  illustrates a section in the area of a vehicle floor of a vehicle body of a vehicle in a view from above; 
         FIG. 2  is a perspective view of a vehicle interior; 
         FIGS. 3-1  to  3 - 6  illustrate a perspective view of the vehicle interior to illustrate an installation sequence of a three-seat bench in a second row of seats; 
         FIGS. 3-7  to  3 - 11  are a perspective view of the vehicle interior obliquely from the back to illustrate an installation sequence of a three-seat bench in a third row of seats; 
         FIG. 3-12  is a left and right illustration a seat arrangeable at a base seat on the right, whereby the seat in the left illustration is shown from the back and the seat in the right illustration from below. 
         FIG. 3-13  is a view of the vehicle interior in the area of the second row of seats; 
         FIG. 3-14  is a view of the vehicle interior in the area of the third row of seats; 
         FIGS. 4-1  to  4 - 4  are a perspective illustration of the second and the third row of seats with different possible single-table functions; 
         FIG. 5  is a perspective illustration of a rolled-up position in the example of the third row of seats; 
         FIGS. 6-1  and  6 - 2  are perspective views of the vehicle interior from the right and left with an easy-entry folded position of a particular side seat in the second row of seats; 
         FIGS. 7-1  to  7 - 3  are perspective views of the vehicle interior from its back to illustrate a changeability of the interior to create additional storage space; 
         FIG. 8  is a seat bench of the second or third row of seats with integrated ISOFIX connectors and top-tether connectors; 
         FIGS. 9-1  and  9 - 2  are a seat bench ( FIG. 9-1 ) and a single vehicle seat ( FIG. 9-2 ) with the illustration of the material concept; 
         FIGS. 10-1  to  10 - 7  are a technical solution for realizing an easy-entry folded position and the removal solution for freely floating side seats relative to the base seats; 
         FIGS. 11-1  to  11 - 3  are a further technical solution for realizing an easy-entry folded position and a further removal solution for freely floating side seats relative the base seats; 
         FIGS. 12 and 13  are a basic version of a seat bench in a second or third row of seats; 
         FIG. 14  is an alternative seat concept of a seat bench in a second or third row of seats; and 
         FIG. 15  illustrates possible seat variants. 
     
    
    
     DETAILED DESCRIPTION 
     The arrangement of a vehicle seat within a motor vehicle and its usual direction of travel determine the following direction information. In or opposite to the direction of travel corresponds to the x-direction, and the vertical in a vehicle is established with the z-direction, whereby the axes transverse to the direction of travel run in the y-direction. 
     Further, the sides of a vehicle  100  which lie in the normal direction of travel x are designated as the left and right side. A seat bench S in the usual installation state relative to a longitudinal direction of the vehicle in x-direction lies transverse to the longitudinal direction x in the y-direction. 
     In the following description of the figures, the same reference characters are always used for the same components and parts, whereby reference characters repeating in the figures are sometimes not repeated. 
       FIG. 1  shows a section in the area of a vehicle floor  102  of a vehicle body  101  of a vehicle  100  in a view from above. Vehicle  100  has a first row of seats  1 , a second row of seats  2 , and a third row of seats  3 . The first row of seats  1  is not shown in greater detail. For example, a single vehicle seat for the driver and a single vehicle seat for the front passenger are arranged in the first row of seats  1 . It is also possible to arrange a single vehicle seat for the driver and two front passenger seats as a double seat bench S in the first row of seats  1 . Finally, a three-seat bench S for the driver and two front passengers can also be arranged in the first row of seats  1 . In this case, the arrangement of a typical three-seat bench or a seat bench S is possible, as this is used according to the invention in the second and third row of seats  2 ,  3  in a vehicle  100 . The seat benches S of the invention are described in greater detail in the following figures. The section in the area of vehicle floor  102  shows that the second and third row of seats  2 ,  3  are each assigned only four attachment points  103 . Said attachment points  103  are located in or on vehicle floor  102  and in regard to a central axis, running in the longitudinal direction x, of vehicle  100  are arranged symmetrically to the left and right of said central axis. As  FIG. 1  already shows, the second row of seats  2  is equipped with an easy-entry function, whereby the easy-entry function and the function of the third row of seats will still be described in greater detail below. 
       FIG. 2  shows, in a perspective view of an interior of vehicle  100 , vehicle floor  102  and attachment points  103  for the second and third row of seats  2 ,  3 , which in regard to the central axis, running in the longitudinal direction, of vehicle  100  are arranged symmetrically to the left and right of said central axis. 
       FIGS. 3-1  to  3 - 6  each show a perspective view of the interior of vehicle  100  obliquely from the front to illustrate an installation sequence of a three-seat bench S in a second row of seats  2 . 
     The explanation of the installation sequence in a first embodiment variant is based on a vehicle body  101 , which has a left side door  104 L and a right side door  104 R. 
     The three-seat bench S comprises a middle base seat  2 M and a left seat  2 L and a right seat  2 R. According to  FIG. 3-1 , middle base seat  2 M is first brought into the interior of vehicle  100 , whereby backrest  22 M is preferably folded down on seat part  12 M. According to  FIG. 3-2 , middle base seat  20 M is placed on the four attachment points  103 . The design of the connection between body-side attachment points  103  and middle base seat  2 M will be discussed in greater detail below. After middle base seat  2 M has been placed, backrest  22 M of middle base seat  2 M can be folded up. This situation is shown in  FIG. 3-3 , whereby it is also shown how right seat  2 R is brought into the interior of vehicle  100  via right side door  104 R. In so doing, backrest  22 R is folded onto seat part  12 R. According to  FIG. 3-4 , right seat  2 R is attached laterally to base seat  2 M. According to  FIG. 3-5 , backrest  22 R can then be already folded up, whereby the figure also shows how left seat  2 L is brought into the interior of vehicle  100  via left side door  104 L. In the case of left seat  2 L as well, when left seat  2 L is brought into the interior of vehicle  100 , backrest  22 L is still folded onto seat part  12 L. According to  FIG. 3-6 , left seat  2 L is also attached laterally to middle base seat  2 M and then backrest  22 L is folded up. It is clear in  FIG. 3-6  that side seats  2 L and  2 R are arranged freely floating above vehicle floor  102 . If only a two-seat bench S is to be installed, the installation of left or right seat  2 L,  2 R can be omitted. 
       FIGS. 3-7  to  3 - 11  each show a perspective view of the interior of vehicle  100  to illustrate an installation sequence of a three-seat bench S in a third row of seats  3 . 
     Vehicle  100  has a back door  105  through which the third row of seats  3  is installed. The three-seat bench S comprises a middle base seat  3 M and a left seat  3 L and a right seat  3 R. According to  FIG. 3-7 , middle base seat  3 M is first brought into the interior of vehicle  100  via a back door  105 , whereby middle base seat  3 M is first installed on the front two attachment points  103  of the four attachment points for the third row of seats  3 . Backrest  23 M of middle base seat  3 M for this purpose is still folded down on seat part  13 M particularly when the second row of seats  2  has already been installed. According to  FIG. 3-8 , middle base seat  3 M is pivoted down, so that the connection between the four body-side attachment points  103  and middle base seat  3 M is created, whereby the details of the design of the connection will be discussed in greater detail below. 
     After middle base seat  3 M has been placed, backrest  23 M of middle base seat  3 M can be folded up. This situation is shown in  FIG. 3-10 , whereby it is also shown how left seat  3 L is brought into the interior of vehicle  100 . In this case, backrest  23 L is folded onto seat part  13 L. Left seat  3 L is fastened laterally to base seat  3 M. As  FIG. 3-10  and  FIG. 3-11  show, backrest  23 L can then be folded up, whereby right seat  3 R of the third row of seats  3  is mounted analogously to middle seat  3 M. It becomes clear particularly in  FIG. 3-11  that side seats  3 L and  3 R are disposed floating freely above vehicle floor  102 . It is understood that a two-seat bench S can be built into the third row of seats in that the installation of the left or right seat  3 L,  3 R is omitted. 
       FIG. 3-12  shows in a left and a right illustration a seat  2 R,  3 R arrangeable to the right on a base seat  2 M,  3 M of a second or a third row of seats  2 ,  3 , whereby seat  2 R,  3 R is shown from the back in the left illustration and seat  2 R,  3 R is shown from below in the right illustration. It is understood that the illustrated seat  2 R,  3 R arrangeable to the right can also be designed so that it is arranged at a base seat  2 M,  3 M to the left. 
     A cross tube Q, which has an adapter plate A at one end, is connected to seat part  12 R,  13 R. The version with adapter plate A represents a first possible fastening variant. A second fastening variant is presented in  FIGS. 11-1  to  11 - 3 . As  FIG. 3-12  in the left illustration shows, seats  2 R,  3 R are constructed so that they can be placed on adapter plate A and a fitting B between seat part  12 R,  13 R and backrest  22 R,  23 R of the seat. For this purpose, spacer elements made of plastic or rubber can be provided to avoid damaging the structure or chassis parts. The particular seat part  12 R,  13 R is formed on the side of adapter plate A so that it does not form a projection relative to the particular backrest  22 R,  23 R, so that a laterally flat and secure placement of seat  2 R,  3 R, in which seat  2 R,  3 R lies securely and stably on its side, on a vehicle floor  102  is possible, as shown in  FIG. 3-12 . In addition, the construction ensures that the center of gravity, which is shown in both figures by a dot, in spatial terms, is formed centrally within seat  2 R,  3 R. This central center of gravity is particularly important for handling during installation and removal of a side seat  2 R,  3 R or  2 L,  3 L, because the handling is made easier with a central center of gravity. According to the invention, it is also ensured that base seat  2 M,  3 M, precisely like side seats  2 R,  3 R,  2 L,  3 L, also has a central center of gravity, in spatial terms, lying within the structure of seat  2 M,  3 M. 
     The possibility of being able to put a side seat  2 R,  3 R,  2 L,  3 L in the interim laterally and flat on a vehicle floor  102 , is of particular advantage, as the following explanation for  FIGS. 3-13  and  3 - 14  will make clear. 
       FIG. 3-13  shows the interior of vehicle  100  in a plan view in the area of the second row of seats  2 . 
       FIG. 3-13  explains based on the removal sequence in a second embodiment variant, how the removal and installation of seats  2 R,  2 M,  2 L occurs when vehicle body  101  has, for example, only one right side door  104 R. Right side door  104 R is shown on the left in  FIG. 3-13 . 
     In a first step a), right seat  2 R is separated from base seat  2 M and taken out of the interior of vehicle  100 . In this case, backrest  22 R can remain in the sitting position or be folded onto seat part  12 R, before right seat  2 R is removed. 
     In a second step b), backrest  22 L of left seat  2 L is folded onto seat part  12 L. Next, left seat  2 L is separated from base seat  2 M and pivoted by 90°, so that the flat side of adapter plate A and fitting B, which were previously arranged to the side of base seat  2 M, lie on vehicle floor  102 . This procedure can be easily performed, because side seat  2 L or side seats  2 L,  2 R have no understructure and the structure is reduced to the basics, so that the side seats have a low weight overall. As will be explained still further below, the side seats are made of a lightweight material except for some parts, such as, e.g., adapter plate A, so that easy handling for the user is assured. 
     In a third step c), base seat  2 M is unlocked and removed, whereby backrest  22 M can remain in the sitting position or be folded onto seat part  12 M, before base seat  2 M is taken out of the interior of vehicle  100 . 
     In a fourth step d), finally the already folded left seat  2 L is taken out via right side door  14  R. 
     It is understood that the installation is made in the reverse sequence; in other words, left seat  2 L is first placed in the folded state on vehicle floor of  102  across from the right side door  104 R, after which base seat  2 M is installed. Next, left seat  2 L can be connected to base seat  2 M, after which finally right seat  2 R is brought into the interior and connected to base seat  2 M. 
     For easier handling, a handle for carrying seat  2 L,  3 L,  2 R,  3 R, rotated by 90°, can be provided on side seat  2 L,  3 L,  2 R,  3 R. 
       FIG. 3-14  shows the interior of vehicle  100  in a plan view in the area of the second row of seats  2 . 
       FIG. 3-14  explains based on the removal sequence how the removal and installation of seats  3 R,  3 M,  3 L occurs via back door  105 . 
     In a first step a), backrest  23 R of right seat  3 R is folded onto seat part  13 R. Next, right seat  3 R is separated from base seat  3 M and pivoted by 90°, so that the flat side of adapter plate A and fitting B, which were previously disposed to the side of base seat  3 M, lie on the vehicle floor. Of course, the process can also be started with left seat  3 L. Because right seat  3 R lies folded onto its side with the saving of space, it can be easily taken out from the interior of vehicle  100  via trunk lid  105  in the gap between lateral vehicle body  101  and the lateral boundary of base seat  3 M. 
     In a second step b), the process is analogous for left seat  3 L. 
     Finally, in a third step c), seat  3 M is unlocked and removed, whereby backrest  23 M can remain in the sitting position or can be folded onto seat part  13 M, before base seat  3 M is taken out of the interior of vehicle  100 . 
     The installation occurs in the reverse sequence; in other words, base seat  3 M is installed first. Next, the left or right seat  3 L,  3 R is lifted in and fastened to base seat  3 M, whereby left and right seat  3 L,  3 R for fastening to base seat  3 M can be placed in the interim laterally on adapter plate A and fitting B. 
       FIGS. 4-1  to  4 - 4  show in perspective illustrations different options for producing table trays, which are formed by the back of the respective backrest of the seats. 
     For example, according to  FIG. 4-1 , a table is formed both in the second row of seats  2  and in the third row of seats  3  by folding backrest  22 L,  23 L on the left side of vehicle  100 . 
       FIG. 4-2  shows the analogous arrangement on the right side of vehicle  100 . 
     In an alternative embodiment in which a fitting is provided for each backrest, the middle backrests can also be folded down individually to form a table. 
       FIG. 4-3  shows the seat arrangement in which a table tray is formed in each case by the back of backrests  22 L,  22 R,  23 L,  23 R to the left and right of base seat  2 M,  3 M. 
     Finally,  FIG. 4-4  shows a table-like surface, formed by the backs of all backrests of the seats in the second and third row of seats  2 ,  3 . As a result, a large tray-like surface results with increased storage space for placing items in the interior of vehicle  100 . The items can be brought into the interior via back door  105  (not shown) or also via at least one side door  104 L,  104 R (not shown). 
       FIG. 5  shows with the example of the third row of seats  3  that the third row of seats  3  can be changed as a whole from a position for use as seats to a rolled-up position I. For this purpose, first backrests  23 L,  23 M,  23 R are folded onto seat parts  13 L,  13 M,  13 R. Next, the rolled-up position I of the third row of seats can be easily produced, because for rolling up the entire seat bench S only unlocking of back seat feet  53 M of base seat  3 M is necessary, in order to be able to pivot seat bench S over the front seat feet  53 M of base seat  3 M. The seat feet remain firmly anchored in vehicle floor  102 . The pivoting movement is possible, because seat part  13 M of base seat  3 M is hinged pivotably relative to front seat feet  53 M. This advantage is due to the low number of attachment points  103  of a seat bench S on vehicle floor  102 . The freely floating seats  3 L,  3 R relative to vehicle floor  102  need not be unlocked separately from vehicle floor  102  for rolling up seat bench S. 
       FIGS. 6-1  and  6 - 2  each show a perspective view from the right and left into the interior of vehicle  100  with an easy-entry folded position II of a particular side seat  2 R,  2 L of the second row of seats  2 . Said easy-entry folded position II, in which the particular side seat  2 R,  2 L with folding of backrest  22 R,  22 L onto seat part  12 R,  12 L is brought into a forward pivoted position, makes possible easier access to the third row of seats  3  for a passenger. Easy-entry folded positions II are known per se. The associated detailed technical solution for carrying out the easy-entry folded position II is described in detail in  FIGS. 10-1  to  10 - 6 . 
       FIGS. 7-1  to  7 - 3  show in perspective views the interior of the vehicle from its back to illustrate the changeability of the interior to create additional storage space. 
     In order to be able to bring, for example, an item about W/H/D 300×1300×2000 mm in size into the interior of vehicle  100 , as in  FIG. 7-1 , left seat  3 L of the back row of seats  3  is removed via trunk lid  105 . Next, as  FIG. 7-2  shows, left seat  2 L of the second row of seats  2  is removed. The particular advantage is that side seats  2 L,  3 L are not connected to the vehicle body, so that the storage surface for an item is free of any fixtures or fittings. The side seats must be separated from base seat  2 M,  3 M by the simply retained unlocking devices and because they are produced in addition in a lightweight manner they can be removed simply and easily by a person.  FIG. 7-3  shows how transport item  106  is accommodated in the interior of vehicle  100 . Additional storage space can also be created in the right area of the interior in the described manner. The entire interior can be used as storage space by removing base seats  2 M,  3 M. 
       FIG. 8  shows that in seats  2 L,  2 M,  2 R and  3 L,  3 M,  3 R of a seat bench S of the second and/or third row of seats  2 ,  3 , ISOFIX connectors  107  for child safety seats are integrated with a lower connector and further top-tether connectors  108  for child safety seats with a lower connector via ISOFIX connectors  107  and with an additional top connector by means of a safety strap. 
     In the following figures additional technical details are explained for the seat concept in association with the previously presented concept. 
     The lightweight concept for a seat bench S and particularly that for a base seat  2 M,  3 M are illustrated in  FIGS. 9-1  and  9 - 2 . 
     As  FIG. 9-1  shows, it is proposed in an embodiment to produce seat feet  52 M,  53 M and the structure of seat part  12 M,  13 M as a whole from a steel material. It is provided in this case to provide the structure of seat part  12 M,  13 M in the back area with fitting parts  32 M,  33 M, which leads off substantially at right angles proceeding from seat part  12 M,  13 M in the direction of a backrest  22 M,  23 M in the sitting position. Backrest  22 M,  23 M of base seat  3 M is made of a lightweight material, whereby inserts as fitting parts  42 M,  43 M on the backrest side made of steel material are integrated into the lightweight material of backrest  22 M,  23 M in the area of fitting parts  32 M,  33 M on the seat part side. 
     In addition, backrest connectors  62 M,  63 M, integrated into backrest  22 M,  23 M of base seat  2 M,  3 M, are also made of a steel material and connected to backrest  22 M,  23 M. In particular the side structure parts of seat part  12 M,  13 M of base seat  2 M,  3 M are produced from a steel material, because they must absorb the dead weight of side seats  2 R,  3 R or  2 L,  3 L and in addition in case of a crash the crash forces arising in base seat  2 M,  3 M itself and in side seats  2 R,  3 R or  2 L,  3 L and introduced into base seat  2 M,  3 M. Side seats  2 R,  3 R or  2 L,  3 L are also produced from a lightweight material, whereby the seat part-side understructure comprises components made of a steel material, so that a stable connection to base seat  2 M,  3 M is assured. In particular, the fastening to base seat  2 M,  3 M occurs via steel parts, which will be described in still greater detail below with reference to the figures. The seat part-side understructure of side seats  2 R,  3 R or  2 L,  3 L made of steel material is not visible in  FIG. 9-1 . 
     As  FIG. 9-2  shows, it is proposed in a second embodiment to produce seat part  12 M,  13 M of base seat  2 M,  3 M from a lightweight material and at exposed sites where especially high forces are introduced into the seat part structure, to integrate inserts made of a steel material into the seat part structure made of a lightweight material. In the left illustration of  FIG. 9-2 , a single base seat  2 M,  3 M is shown which is produced substantially from a lightweight material. The fitting part  42 M,  43 M on the backrest side is integrated into backrest  22 M,  23 M otherwise made of a lightweight material. In the particular side part (shown as transparent) of seat part  12 M,  13 M (see illustration at bottom right), a fitting  32 M,  33 M on the seat-part side is integrated as an insert made of steel material in the side part otherwise produced from the lightweight material. Further, a frame-like reinforcement structure  72 M,  73 M is molded laterally in the lightweight material, whereby receiving elements  72 - 1 M,  73 - 1 M project on both sides from the lightweight material of the side parts and function to accommodate side seats  2 L,  3 L or  2 R,  3 R. Finally, another insert is arranged in the front area and optionally in addition also in the back area (not visible) of the particular side part, which in each case form a seat foot  52 M,  53 M, projecting from the lightweight material, of base seat  2 M,  3 M. In the illustration at the top right, the side part is not shown as transparent, so that only projecting receiving elements  72 - 1 M,  73 - 1 M and projecting seat feet  52 M,  53 M are visible. The illustrated receiving elements  72 - 1 M,  73 - 1 M are used to receive the already mentioned adapter plate A, which will be dealt with in greater detail below. 
       FIGS. 10-1  to  10 - 6  show a technical solution for realizing the easy-entry folded position II of the decoupling or removal of the freely floating side seats  2 R,  2 L,  3 R,  3 L. At the same time, the material selection in regard to the connection of side seats  2 R,  2 L,  3 R,  3 L to base seats  2 M,  3 M will be addressed. 
       FIG. 10-1  shows once more for clarification a three-seat bench S, which can be installed in the second or third row of seats  2 ,  3 . 
     Three-seat bench S is shown in  FIG. 10-2  in a side view from the left. Right seat  2 R,  3 R, in which backrest  22 R,  23 R is already folded down onto seat part  2 R,  3 R, is in front. As a result, backrest  22 M,  23 M of base seat  2 M,  3 M is visible in the background. Because right seat  2 R,  3 R is arranged freely floating at base seat  2 M,  3 M, in  FIG. 10-2  the side part of base seat  2 M,  3 M is also visible. The already described receiving elements  72 - 1 M,  73 - 1 M, which are provided for receiving adapter plate A of right seat  2 R,  3 R, project from said side part. Moreover, the face side of cross tube Q and seat feet  52 M,  53 M, projecting from the side part, are visible in the front and back area. Here, it is already evident that seat feet  52 M,  53 M have locking hooks, which enable fastening of base seat  2 M,  3 M in attachment points  103  of vehicle floor  102 . 
     Backrest-side fitting  42 M,  43 M and the seat part-side fitting  32 M,  33 M, seat feet  52 M,  53 M, and receiving elements  72 - 1 M,  73 - 1 M, which lead off from reinforcement structure  72 M,  73 M within the side part of base seat  2 M,  3 M, are produced from a steel material. Adapter plate A is also produced from a steel material and is connected to the side part of base seat  2 M,  3 M via receiving elements  72 - 1 M,  73 - 1 M, projecting from the side part; two of these are preferably arranged above and two below. Adapter plate A has fastening elements A 1  for this purpose. 
       FIG. 10-3  shows right seat  2 R,  3 R with the same reference characters in its easy-entry folded position II. Right seat  2 R,  3 R in the first fastening variant is pivoted forward in the x-direction via cross tube Q leading off in the y-direction from adapter plate A in the normal installation state in the direction of travel. 
     Before the pivoting can be carried out, a retaining device, comprising a retaining element H 1  and a retaining element seat H 2 , must be unlocked. Said retaining device is shown in  FIG. 10-4 . As  FIG. 10-3  shows, it is disposed in the back area of right side seat  2 R,  3 R. 
       FIG. 10-4  provides a perspective view, obliquely from the back, of the retaining device and adapter plate A and of cross tube Q leading off from adapter plate A. After the retaining device has been unlocked by a user, seat  2 R,  3 R can be pivoted into the easy-entry folded position II. 
     The retaining device is of particular advantage, because the seat part-side retaining element H 1  has its own spring element on which a ring rests, whereby the spring element and ring sit on a bolt, which has a conical tip. During locking of right seat  2 R,  3 R, said conical tip engages in retaining element seat H 2 , which is disposed in a web A 3  leading off laterally from adapter plate A. In this regard, the ring is moved against the bolt and the spring element is tensioned. The movement of the ring frees elements which in a groove of retaining element seat H 2  result in the locking of right seat  2 R,  3 R. In the case of unlocking of right seat  2 R,  3 R, the locking in retaining element seat H 2  is canceled and the spring element assures that the back area of right seat  2 R,  3 R rebounds and easily raised. A user senses and sees in an advantageous manner that the seat is released for carrying out the pivoting movement into the easy-entry folded position II. 
       FIG. 10-4  shows further the back top fastening element A 1  and the back top locking element A 2 . It is shown in addition that right seat  2 R,  3 R is connected pivotably to cross tube Q via cross tube receiving member Q 1 . 
       FIG. 10-5  shows side seats  2 R,  3 R in a view from the front. The two cross tube receiving members Q 1  are shown, whereby right cross tube receiving member Q 1  has in addition a fixing element F 1 , which protrudes laterally in the y-direction coaxially to the axis of cross tube Q towards cross tube receiving member Q 1 . A fixing element receiving member F 2  with a recess is located on cross tube Q. If right seat  2 R,  3 R is pivoted into the easy-entry folded position II, fixing element F 1  also pivots and goes with a free end onto fixing element receiving member F 2 , until the end piece of the bolt, cylindrical in this exemplary embodiment, snaps into the recess of fixing element receiving member F 2 . The pivoting angle of the easy-entry folded position II can be set according to the arrangement of fixing element receiving member F 2 .  FIG. 10-5  shows in addition that a buffer element P is disposed in the area of the conical transition from adapter plate A to cross tube Q. Said buffer element P has two contact surfaces with which a retaining part of the understructure of seat  2 R,  3 R comes into contact in the normal position and in the easy-entry folded position. As a result, when the end positions are reached, a hard stop of right seat  2 R,  3 R is avoided. 
       FIG. 10-6  shows in a view, obliquely from outside, of adapter plate A that, for example, four (two above, two below) fastening elements A 1  and two locking elements A 2  are disposed in adapter plate A. Fastening element A 1  lying above and in back and locking element A 2  are not visible. They lie on adapter plate A behind retaining device H 1 , H 2 . Fastening elements A 1  and locking elements A 2  serve to fasten right seat  2 R,  3 R to the side part of base seat  2 M,  3 M, as shown in  FIG. 10-7 . 
       FIG. 10-7  shows in three sequences, in each case a top and bottom illustration, right seat  2 R,  3 R in perspective illustrations obliquely from the front. 
     In the two left illustrations, right seat  2 M,  3 M is not yet unlocked. In the two middle illustrations, right seat  2 M,  3 M is already unlocked and is being raised. In the two right illustrations, right seat  2 M,  3 M is lifted out of receiving element  72 - 1 M,  73 - 1 M; i.e., adapter plate A of right seat  2 M,  3 M is separated from base seat  2 M,  3 M. The rectangular areas of the arrows shown in the three top illustrations are reproduced in the enlarged details of the three lower illustrations. 
     Receiving element  72 - 1 M,  73 - 1 M will be discussed first. Said receiving element is formed as a 90° angle and is attached with its spectacle-like side in the x-direction to the side part of base seat  2 M,  3 M. In the angled area leading off from this, in each case a top and bottom receiving hook  72 - 13 ,  73 - 13  is disposed, in which the bolt-like fastening elements A 1 , running in the x-direction, engage. In the angled area, moreover, an opening  72 - 12 ,  73 - 12  is arranged in which locking element A 2  engages. The three bottom illustrations show only the top front receiving element  72 - 1 M,  73 - 1 M. In the back top area, there is an analogously made receiving element, whereby a receiving element, which has at least one receiving hook, is disposed in the front and back in the bottom area. There is a spring element receiving member  72 - 11 ,  73 - 11  in the corner of the two angled areas of the two top receiving elements  72 - 1 M,  73 - 1 M, whereby receiving hooks  72 - 13 ,  73 - 13  have a functional connection with a spring element in spring element receiving member  72 - 11 ,  73 - 11 . This arrangement has the following important advantage. 
     First, the seat is still locked according to the two left illustrations. In the locking of seat  2 R,  3 R, bolt-like fastening elements A 1  are hooked into receiving hooks  72 - 13 ,  73 - 13 . Then, right seat  2 R,  3 R is pressed downward in the z-direction, as a result of which the front and back fastening element A 2  snaps into opening  72 - 12 ,  73 - 12 . Right seat  2 R,  3 R is locked to base seat  2 M,  3 M. In this movement in the z-direction, at least the front and back top receiving hooks  72 - 13 ,  73 - 13  are moved downward and the spring element is tensioned in the spring element receiving member  72 - 11 ,  73 - 11 . 
     This function is utilized advantageously during the unlocking of right seat  2 R,  3 R. In the bottom left illustration, an unlocking element E is shown, which is used to unlock right seat  2 R,  3 R, and ensures that locking element A 2  is brought out of openings  72 - 12 ,  73 - 12 . The direction of movement of unlocking element E is shown by an arrow and occurs preferably in the x-direction. Other directions of movement are also conceivable. After the release of the locking of right seat  2 R,  3 R, the tensioning force of the spring element in spring element receiving member  72 - 11 ,  73 - 11  ensures that at least the two top receiving hooks  72 - 13 ,  73 - 13  lift right seat  2 R,  3 R upward relative to base seat  2 M,  3 M in the z-direction. For the user it is again visible optically and also perceptible that right seat  2 R,  3 R is decoupled and is ready to be removed from base seat  2 M,  3 M. The right bottom illustration shows that front fastening elements A 1  and front unlocking element A 2  have been taken out of receiving elements  72 - 1 M,  73 - 1 M. 
       FIG. 11-1  once again shows in a perspective view obliquely from the front for clarification a three-seat bench S, which can be installed in the second or third row of seats  2 ,  3 .  FIG. 11-1  already shows that a frame R is disposed between right seat  2 R,  3 R and base seat  2 M,  3 M. 
     The decoupling of left seat  2 L,  3 L is shown in  FIG. 11-2  in a left illustration in a perspective view from the right obliquely from the front. The two right illustrations aid in the description. The top right illustration shows base seat  2 M,  3 M and left seat part  2 L,  3 L in the area of its seat parts  12 M,  13 M and  12 L,  13 L from the front. A joint arrangement G with a top and bottom joint is made between the two seat parts  2 L,  3 L. The shown left side seat  2 L,  3 L can be pivoted hinge-like on a z-axis in the y-direction via the two joints. A retaining device, which is not visible in this top right illustration, with a retaining element H 1 , which engages in a retaining element seat H 2 , is disposed in the back area of left seat  2 L,  3 L. Retaining element seat H 2  is located on the side part of base seat  2 M,  3 M, which is shown in the bottom right illustration obliquely from the back, so that retaining element seat H 2  is visible. During locking of left seat  2 L,  3 L, retaining element H 1  via the side part of base seat  2 M,  3 M engages in retaining element seat H 2  of base seat  2 M,  3 M and fixes side seat  2 L,  3 L, shown by way of example, to middle base seat  2 M,  3 M. Retaining device H 1 , H 2  can be of the type as was explained in regard to the easy-entry function in the description of  FIG. 10-4 . 
     The longitudinal axis of the retaining device then lies, however, in the y-direction transverse to the direction of travel x. As a result, the advantage is also achieved, here that after unlocking of left seat  2 L,  3 L, left seat  2 L,  3 L is pushed away slightly, so that the user can see and feel that left seat  2 L,  3 L is decoupled in the back area and is ready for removal. Via a, for example, bolt-like mounting, frame R and thereby left seat  2 L,  3 L can be removed from the bolts of the joint in the z-direction via the eyes arranged on it. Frame R, moreover, has horizontal rails, a top rail R 1  and a bottom rail R 2 . The seat part structure of left seat  2 L,  3 L is configured so that the seat can be slid in the top and bottom rails R 1 , R 2 , as shown in  FIG. 1-3 , in the x-direction. After backrest  22 L,  23 L has been folded down relative to seat part  12 L,  13 L, left seat  2 L,  3 L can be slid in the x-direction into an easy-entry folded position II. In this respect, the same functionality in frame R is achieved with this second fastening variant of frame R over rails R 1 , R 2  as in the first fastening variant with adapter plate A and the ability to pivot relative to cross tube Q. 
     With respect to the material selection, the procedure is analogous to what has been described for  FIG. 9-2 . The major difference, however, is that adapter plate A is not made of a steel material, but that joint arrangement G and frame R and rails R 1 , R 2  is formed of steel material. The locking in retaining device H 1 , H 2  and the adjacent parts such as, for example, the cross member of base seat  2 M,  3 M, which forms the retaining element seat H 2 , is also made of a steel material. 
     A basic version with freely floating side seat parts  2 R,  3 R,  2 L,  3 L for a three-seat bench S in the second or third row of seats  2 ,  3  can be formed as depicted in  FIG. 13 , so that in each case modular screw connection M directed toward base seat  2 M,  3 M are provided. This more economically priced third fastening variant is also suitable for vehicles  100  in which removal of the side seats is necessary only rarely. The modular screw connections M are shown in  FIG. 12 . 
     It can be provided alternatively that the second or third row of seats  2 ,  3  or even the first row of seats  1  is made with a single seat  2 R,  3 R and a double seat bench D. Said double seat bench D has the same features as base seat  2 M,  3 M in the connection area to single seat  2 R,  3 R, which is disposed on the right in  FIG. 14 , but of course, can also be disposed on the left. It is understood that the attachment points can be arranged on vehicle floor  102  not as shown in  FIG. 2 , but must be arranged according to this configuration. 
     But this alternative configuration also enables the provision of six seating places in the second or third row of seats  2 ,  3  with only four or eight attachment points  103  in vehicle floor  102 . 
     With consideration of the first row for the driver and front passenger, a maximum of nine seating places result together with the first and second row of seats behind them (total n=3), for which only twelve attachment points  103  on vehicle floor  102  must be provided. 
     In the long versions of some vehicles, even a further three rows of seats, thus a total of four (n=4) rows of seats, are arranged apart from the row for the driver and front passenger. In the case of a maximum number of three seats each, the vehicle is thus equipped with twelve seats, for which only sixteen attachment points  103  are necessary in vehicle floor  102  or in the body-side rails. 
     If two single seats are provided in the first row of seats  1 , a plurality of seating arrangements result, whichever single seat  2 L,  2 M,  2 R,  3 L,  3 M,  3 R (without consideration of the alternative concept,  FIG. 14 ) is arranged in the vehicle interior. It is understood that in the solution of the invention no left or right seat alone can be arranged in the vehicle interior. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.