referring to fig1 and 2 , an article introduction slide assembly 1 is formed by two co - planar plates 1a and 1b spaced apart a controllable distance , and intended to receive knit fabric parts 2 and 3 ( fig5 ) constituting the front and the back of a pullover to be assembled to form a finished article . these knit fabric parts 2 and 3 are provided at their selvedges 2a , 3a with retaining members facilitating their suspension in the slide assembly 1 . an endless belt 4 , mounted above the slide assembly 1 on rollers 5 , 6 , carries at least one shoe 7 arranged to contact the selvedges of the articles so as to displace the articles , suspended in the slide assembly 1 , towards an automatic assembling machine for seaming the selvedges , for example , the machine described in french patent application no . 73 . 39606 referred to hereinbefore . the belt 4 may be replaced by a chain and sprocket wheels . the installation further includes a first guide rail 8 extending parallel to the vertical plane of symmetry of the slide assembly 1 . the rail 8 is fixed at 9 to the structure of the assembling machine ( not otherwise shown ) and is inclined to the horizontal upwardly in the direction toward the slide assembly . a slide member 10 slides on the rail 8 and carries a pair of calipers 11 pivoted about an axis 11a extending parallel to the rail 8 . the verticle plane of symmetry of the calipers 11 is substantially in alignment with that of the slide assembly 1 . the lower ends of the calipers 11 lie a few millimeters above the end of the entry to the slide assembly 1 when the slide member 10 lies adjacent this end . the movement of the slide member 10 is limited downwardly by an abutment 12 adjustably fixedon the lower part of the rail 8 . a second guide rail 13 secured to the structure of the assembling machine extends substantially parallel to the vertical plane of symmetry of the slide assembly 1 , and lies beneath the rail 8 . the rail 13 is inclined to the horizontal upwardly in the direction of the slide assembly 1 . a carriage 14 mounted on the rail 13 comprises a support 15 rigid with a slide member 16 slidable on the rail 13 . the carriage 14 carries a slide assembly 17 constituted by two co - planar plate parts 17a , 17b screwed to the support 15 . a slot 18 , ( see fig4 ) formed in the support 15 corresponds to a similar slot of the slide assembly 17 . the spacing between the parts of the plate 17a , 17b is variable in order to adapt to the thickness of the articles to be transferred to the assembling machine , similarly to the spacing between the plate 1a , 1b constituting the slide assembly 1 . the position of the plate parts 17a , 17b on the support 15 and the inclination of the rail are such that the ends of the parts of the plate can abut with the inclined end parts 1 &# 39 ; a and 1 &# 39 ; b of the plates 1a and 1b . in this position , the slide assembly 1 and the slide assembly 17 form extensions of one another and their planes of symmetry coincide . a retaining finger 19 is pivotally mounted about a pin 20 carried by the support 15 . at one end 19a , the finger 19 is controlled by a return spring 21 , supported on the slide member 16 . under the action of this spring , the other end 19b of the finger 19 is applied against an abutment 22 rigid with the support 15 . the pin 20 and the abutment 22 are situated on opposite sides of the slot of the slide assembly 17 , the retaining finger 19 serving to close the slot in the slide assembly when it engages against the abutment 22 . the carriage 14 comprises a brake 23 constituted for example by a shoe 24 rigid with a piston slidable in a cylinder 25 carried by the slide member 16 . the brake 23 is pneumatically actuated , the cylinder 25 being connected by a pipe 26 to a source of pressure fluid ( not shown ). the pressure exerted by the shoe 24 on the rail 13 is adjustable so as to control the intensity of the braking action on the carriage 14 . an abutment 27 , adjustably secured to the lower part of the rail 13 limits downwardly the passage of the carriage 14 . the lower ends of the calipers 11 follow a trajectory parallel to the rail 8 and pass a few millimeters above the entry to the slide assembly 1 while the part of the carriage 14 , when moving below the calipers 11 follows a trajectory parallel to the rail 13 and passes by the entry end of the slide assembly 1 . in order to avoid all contact between the calipers 11 and the carriage 14 , the angle of inclination with respect to the horizontal of the rail 13 is selected to be at least equal to that of the rail 8 . the operation of the installation will be described hereinafter in use for transfer of article parts such as 2 and 3 ( fig5 ) intended to form a pull - over , the assembling machine effecting the sewing together of the selvedges 2a and 3a of the article parts extending from the belt parts 2b , 3b to the cuff parts 2c , 3c . one or more retaining points are previously provided on the selvedges 2a , 3a particularly at the level of the under - arm joint 2d . the article parts 2 and 3 are initially suspended manually by an operator by introduction of the under - arm joint 2d or of a portion of the selvedges 2a , 3a adjacent to this under - arm joint , between the calipers 11 , the slide member 10 resting against the abutment 12 . these calipers have been opened previously and the introduction of the under - arm joint 2d causes the operation of a feeler 28 ( fig3 ) comprising a rod 28a which extends transversly in the space between the individual ends of the calipers 11 or a zone adjacent this space . displacement of the rod 28a controls the closure of the calipers 11 by a pneumatic cylinder 29 connected to a source of pressure fluid through a pipe 30 . after under - arm joint 2d has been gripped by the calipers 11 , the article parts 2 and 3 are suspended and the operator then proceeds manually to introduce the ends of the selvedges 2a and 3a at the level of the belt 2b , 3b , into the slide assembly 1 , the retaining members formed along these selvedges resting on the upper faces of the plates 1a , 1b . as soon as the shoe 7 is applied to the front ends of the article parts 2 , 3 engaged in the slide assembly 1 , the parts 2 and 3 are moved in a translatory sense in the slide assembly and themselves drive the calipers 11 and their slide member 10 along the guide rail 8 . the operator then proceeds with the introduction of the ends of the selvedges 2a and 3a , at the level of the end edges of the sleeve 2c , 3c , into the slide assembly 17 , the slide member 16 then resting against the abutment 27 . this introduction of the rear ends of the article parts 2 , 3 into the slide assembly 17 is effected until the moving knit fabric causes the retaining finger 19 to pivot which , biased by the spring 21 , wedges the knitwear against the abutment 22 and secures it in the slide assembly 17 . approximately during the introduction of the rear end of the article parts 2 , 3 , into slide assembly 17 , the calipers 11 arrive at the level of the intake end of the slide assembly 1 , holding the under - arm joint 2d a few millimeters above this intake end . the slide member 10 then comes into contact with a feeler 31 , secured to the rail 8 . this feeler , when actuated , controls the opening of the calipers 11 by interrupting the fluid supply to the pneumatic cylinder 29 and the slide member 10 carrying the calipers 11 returns under gravity to the abutment 12 . the introduction of the sleeve , beyond the under - arm joint 2d is effected continuously by the traction exerted by the belt 4 . the controllable brake 23 exerts a slight resistance to the displacement of the carriage 14 along the rail 13 , in order to impart a light tension to the knitwear to allow its correct introduction into the slide assembly 1 . when the parts of the plate 17a , 17b come into abutment with the intake end of the slide assembly 1 , the carriage 14 actuates a feeler 32 disposed laterally with respect to the intake end . the feeler controls , through an air cylinder 33 carried by the carriage 14 and connected by a pipe 34 to a source of fluid under pressure , the pivoting action of the retaining finger 19 in opposition to the force exerted by the spring 21 . the rear ends of the article parts 2 and 3 being freed , the edge 2c , 3c of the sleeve passes directly from the slide assembly 17 to the slide assembly 1 . the action of the brake 23 is interrupted by cutting off its supply of fluid under pressure , this cut - off being controlled by the feeler 32 aftera predetermined delay . the carriage 14 again descends under gravity and abuts against the abutment 27 . the return of the carriage 14 to the abutment 27 causes the actuation by the slide member 16 of a feeler 35 mounted on the abutment 27 , which feeler controls the re - establishment of braking action by the brake 23 and the return of the retaining finger 19 against the abutment 22 . during the introduction of the sleeve of the article part to the slide assembly 1 , the operator can prepare the positioning of the following articles and the suspension thereof in the calipers 11 . the cylinders 29 , 33 and the pneumatic brake 23 are controlled by the feelers 28 , 31 32 and 35 which act through the intermediary of control circuits on electrically - operated valves 36 , 37 , 38 ( fig6 ) incorporated respectively in the pipes 30 , 34 and 26 . an embodiment of the control circuits is illustrated in fig6 . the feelers 28 , 31 , 32 , 35 when they are actuated , cause the closure of switches 39 , 40 , 41 , 42 each having one contact connected to a potential source 43 . the second contacts of the switches 39 , 40 are connected respectively to the first input 44a and the second input 44b of a bistable 44 , the output 44c of which is connected to the driving circuit of the electrically - operated valve 36 . when the bistable 44 receives a signal at its input 44a following the closure of the switch 39 , it emits an output signal causing opening of the electrically - operated valve 36 and the closdure of the calipers 11 by the cylinder 29 , which output signal is interrupted on the generation of a signal at its input 44b following the closure of the switch 40 . the second contacts of the switches 41 , 42 are connected , on the one hand , respectively to the first input 45a and to the second input 45b of a bistable 45 and , on the other hand , respectively to the first input 46a of a bistable 46 and to the input 47a of a delay circuit 47 . the output 45c of the bistable 45 is connected to the driving circuit of the electrically - operated valve 37 so as to control the opening of this electrically - operated valve and the pivoting of the finger 19 between the instants corresponding to the closures of the switches 41 and 42 . the output 47b of the delay circuit 47 is connected to the second input 46b of the bistable 46 the output 46c of which is connected to the driving circuit of the electrically - operated valve 38 so as to control the interruption of the supply to the brake 23 between the instant of closure of the switch 42 , delayed by the circuit 47 and the instant of the closure of the switch 41 . the circuit 47 introduces a delay of which the duration is selected to be in excess of that of the transfer to the slide assembly 1 of the end parts of the article parts 2 and 3 , introduced into the member of the slide assembly 17 . in an unillustrated modification the slide member 10 supporting the calipers 11 has a pneumatic braking device with a structure and operation similar to those of the brake forming part of the equipment of the carriage 14 . moreover , it is possible to replace such a braking device by additional masses secured to the slide member .