fig1 shows a perspective view of a feed station with a modular placement device . the modular placement device 1 has a housing 10 with a feed deck 11 and a placement element 14 . the placement element 14 is realized as a pendulum that is angled towards a stack ( not shown ) lying on the feed deck 11 and thus can exert a pressure on said stack . the rollers 111 in the feed deck 11 reduce the friction of the goods ( mail pieces ) with the feed deck . a slider 16 mounted so as to be able to slide on the feed deck 11 has a first slider wall part 161 and a second slider wall part 162 and a shaft 160 via which the slider wall part 161 can be screwed on opposite the slider wall part 161 when the feed deck is set up at a ramp ( fig6 b ). with the slider a stack can be manually pressed with its lateral edges onto the guide plate of the housing . the housing comprises an upper shell and a lower shell that is covered by the upper shell . a slit - shaped opening is molded in the upper shell , which opening is covered by the slider . the slider 16 is mounted on the feed deck together with a damping mechanism ( not shown ). some of the goods to be isolated can be buckled , bent or compressed by the pressure , which is however gradually , automatically reversed after the manual operation via the damping mechanism arranged within the placement device . the modular placement device also has a coupling mechanism and an additional , passively acting mechanism ( not shown ) under the feed deck in order to arrest the feed deck ( which can be set up at a ramp ) at a desired angle or to release it again ( not visible ). the feed station 2 follows the modular placement device 1 in the transport direction ( direction x ). the feed deck 21 of the feed station 2 has a width ( extending in the y - direction from the front to a rear stop ) and lies parallel to the x / y - plane , which forms a base surface . the superstructures of the feed station 2 extends perpendicularly to the base surface , i . e . in the z - direction . the mail piece width is determined by the widest mail piece and the height of the superstructures is determined by the maximum height of a mail piece that can presently still be isolated and transported . a container for sealing fluid , a moistener for flaps of envelopes and a closing device for envelopes can be included in the superstructures . the height of the feed deck 21 above the base surface is determined by the height of a transport device ( not shown ) for mail pieces that is installed in the feed station . fig2 shows a basic illustration of an angle lever that can be constructed from two similar triangles with the points a 1 , c 1 , d and d , c 1 , b 1 and has a pivot d . the distance a 1 - d thereby forms a lever arm with the radius r , and the distance b 1 - d forms a lever arm with radius d around the pivot d . the distance a 1 - c 1 has a length a and is realized as a shorter pendulum arm 141 of a pendulum 140 . the distance b 1 - c 1 has a length b and is realized as a longer pendulum arm 142 of the pendulum 140 . the distance c 1 - d has a length c and is realized as a pendulum support 144 that adjoins the internal angle δ of the pendulum 140 and reaches at least to the pivot d . the pivot d lies at a vertical distance above the feed deck 11 on a rotation axis that proceeds in a bearing or a bearing shell 12 . a rotation axis 13 that is situated orthogonal to a vertical ( z - direction ) and orthogonal to a horizontal ( transport direction x ) travels through the pivot d . the angle ( designated with a point ) between the sides r and c or , respectively , c and b of the triangle can be a right angle or can be greater than 90 °, up to approximately 110 °. the sides a and c or , respectively , d and b of the triangle enclose an acute angle γ , for example γ = 30 °. after a leftward rotation of the pendulum 140 around the pivot d , the lever arm with the radius d reaches an angle β 1 ( for example β 1 = 20 °) while the lever arm with the radius r reaches an angle α 1 ( for example α 1 = 25 °). weights ( not shown ) that exert respective forces f a1 and f b1 on the respective lever arms in the direction of gravity act at the ends a 1 and b 1 of the lever arms . a plot of the lever arm r on the horizontal yields a length l a1 = r · cos α 1 that is effective for the gravitational force is shown in the upper part of fig2 . a plot of the lever arm on the horizontal yields a length l b1 = d · cos β 1 that is effective for the gravitational force and is likewise shown in the upper part of fig2 . if both arms of the pendulum 14 are at equilibrium , hooke &# 39 ; s law applies : beyond the equilibrium , the pendulum tips in the direction of the arrow drawn with a dash - dot line . after a rightward rotation of the pendulum 140 around the pivot d , the lever arm with the radius d reaches an angle β 2 ( for example β 2 =− 20 °) while the lever arm with the radius r reaches an angle α 2 ( for example α 2 = 50 °). the weights ( not shown ) again act at the ends a 2 and b 2 of the lever arms r and d . a plot of the lever arm r on the horizontal yields a length l a2 = r · cos α2 that is effective for the gravitational force is shown in the upper part of fig2 . a plot of the lever arm r on the horizontal yields a length l b2 = d · cos β 2 that is effective for the gravitational force is likewise shown in the upper part of fig2 . the effective length l b2 = d · cos β 2 is equal to the effective length l b1 = d · cos β 1 . although the weights have not changed , however , equilibrium no longer exists because the effective lengths have changed at the side of the pendulum arm 141 , such that now : a small stack 32 upon isolation is presented in principle in fig3 a . the stack 32 with a height h 2 lies on rollers 111 of the feed deck 11 and on an ejection roller 22 . the lowermost mail piece is pulled via a rotation of the driven ejection roller 22 around the rotation axis 21 . the rotation direction is identified with a black arrow , and the ejection direction is identified with a white arrow . the longer pendulum arm ( not shown ) presses on the stack 32 with a weight g 2 . the sum of the weight g 2 and the weight of the stack add up to a force f 2 . the force f 2 acts on the ejection roller 22 . a large stack 31 upon isolation is presented in principle in fig3 b . if the weight of the longer pendulum arm is greater , such that both arms of the pendulum 140 are not in equilibrium , a weight g 1 likewise acts on a stack 31 that rests on the feed deck and thus on the ejection roller . the sum of the weight g 2 and the weight of the stack add to a force f 1 . the force f 1 acts on the ejection roller , but with the difference that the weight g 1 is smaller than the weight g 2 , and that the stack 31 with the height h 1 is higher than the height h 2 of the stack 32 . fig4 a shows a plan view on a pendulum 140 with the shorter lever arm 141 of the length a and with the longer pendulum arm 142 of the length b , as well as with a middle part 143 of the pendulum . the shorter pendulum arm 141 has the width u and the longer pendulum arm 141 has the width v . both pendulum arms are situated antiparallel to one another and are separated in width by the middle part 143 of the pendulum , wherein the distance w is smaller than the width u or the width v . fig4 b shows a view of the pressure element from the front . the surface of the pendulum support 144 lies parallel to the x / z - plane and , to the left of the center , has a circular opening 1440 around a pivot 13 . a catch 145 is molded toward the bottom on the pendulum support 144 . the pendulum arm 142 strikes the pendulum arm 141 at an angle at an impact point . a diagonal between the pivot 13 and the impact point has a length c . the shorter pendulum arm 141 of length a lies parallel to the x - direction , and the longer pendulum arm 142 of length b lies at an angle to the x - direction . a view from the left of the pressure element and of a bearing shell is shown in fig4 c , wherein the bearing shell 12 is designed to bear the pendulum support 144 and is provided to be plugged into the bearing shell 12 in a shaft - shaped cavity ( not shown ) of the housing of the placement device . the bearing shell 12 has bearing pins 121 , 122 molded on both sides so as to be elastic to support the pendulum support , and has elastically formed detents 123 , 123 for insertion into the shaft - shaped cavity . the pendulum support 144 is molded on the lower part of the pendulum arm 141 . the pendulum arm 142 is molded at an angle on the pendulum arm 141 . the pendulum support 144 has circular openings 1440 with a diameter correspondingly matched to the diameter of the bearing pins 121 , 122 and a catch 145 . the pendulum support 144 is mounted on the bearing shell 12 so that the bearing pins 121 , 122 and openings 1440 lie on a rotation axis 130 . fig5 shows a plan view of the top shell 101 of the housing of the placement device 1 without the pendulum . in its upper shell 101 the housing has a shaft - shaped cavity 15 extending in the x - direction , near the right side wall and the rear wall . a guide wall 17 is provided parallel to the rear wall of the upper housing shell 101 , the distance of which guide wall 17 from the rear wall is co - determined corresponding to the width ( extending in the y - direction ) of the shaft - shaped cavity 15 . a feed deck 11 is arranged at a distance from a base plate , which feed deck 11 includes rollers 111 in order to reduce the friction resistance caused by stiction . a slider 16 arranged so that it can be displaced in the y - direction on the feed deck 11 has a slider plate 163 that is molded on the slider wall part 161 . this allows a stack to be displaced up to a stop on the guide wall 17 . the front view of the placement device 1 that is shown in fig6 a includes the pendulum 140 moved away from the operating position and the upper housing shell 101 , which — together with the feed deck 11 — is placed back in the horizontal plane . the slider has been removed in order to enable a view of the guide wall 17 at the housing 10 . a slit - shaped opening 18 on the front side is provided for the insertion of the slider . the guide wall 17 is drawn in section in order to enable a view of the bearing shell 12 mounted in the housing . the cavity is drawn in section in order to show the shaft wall 151 , the pendulum support 144 inserted into the bearing shell 12 , and the pivot 13 of the pivot 140 . the pendulum rotation to the left is stopped in that the catch of the pendulum support 144 stops at the inner bearing shell wall . this pendulum setting stably persists , which is advantageously usable for insertion of a stack into the placement device . a front view of the placement device with a pendulum 140 in the operating position and a feed deck 11 set up as a ramp is shown in fig6 b . the feed deck 11 can be set up together with the upper housing shell 101 up to an angle of ψ max = 10 °. the pivot 103 of the upper housing shell 101 lies on a horizontal line h on the right size . the lower housing shell 102 lies below the horizontal line h . a stack 3 of mail pieces lies on the feed deck . the weight g of the stack 3 or mail piece acts near the center of gravity and — due to the gravitation — orthogonal to the ramp . the value of a normal force component f n and a downhill slope force component f k is dependent on the weight g of the stack 3 or mail piece , wherein said normal force component f n is situated orthogonal to the surface of the ramp , and wherein said downhill slope force component f k lies on the surface of the ramp and is directed downward in terms of the slope . the friction force f r increases with the normal force component f n . the downhill slope force component is usable to propel the goods to be isolated . given an increasing slope — i . e . an angle ψ of the surface of the ramp relative to the horizontal — the normal force component f n decreases and the downhill slope force component f k increases , wherein the formulas apply : the pendulum 140 presses on the stack 3 with a force f b with the end of the longer pendulum arm in the transition region to the feed station . fig6 c shows a front view of the placement device with slider 16 and with a pendulum 140 that is moved away from the stack covered by the slider , as well as with a coupling mechanism 19 to couple the placement device with a feed station ( not shown ) that follows downstream ( in terms of the flow ) in a franking machine . although modifications and changes may be suggested by those skilled in the art , it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contributions to the art .