Patent GB-918996-A (GB)
IPC: D01H5/56
Filed: 1960-09-08
Abstract: 918,996. Textile drafting mechanism. RIETER & CIE A.G., JOH. JACOB. Sept. 8, 1960 [Sept 11, 1959], No. 31008/60 Class 120 (2). The top pressure rollers of a drafting device are loaded by a weighting lever 17 within an arm 3 pivoted at 4 to a fixed support 2, the weighting lever 17 having a fulcrum connection 21 at its forward end for carrying pressure roll holders 25, 26 and a pivotal connection 30<SP>1</SP> intermediate its length for a link 31 carrying a pressure roll holder 42. The rear end of the weighting lever 17 rests on pressure producing means 9, 10 actuated by pressure fluid in a hose 8 in a tubular pressure fluid in a hose 8 in a tubular carrier 1. The link 31 is pivoted about an axis 34 on a displaceable bracket 13 in the arm 3. Adjustment of position of top pressure rollers.- The pressure roll holder 42 is slidably adjustable along a slotted carrier 33. The rear end of the carrier 33 is supported at 32 by the link 31, and the forward end of the carrier is supported by an element 36 pivoted at 40 to the link 31 and slidable on a pin 39 on the bracket 13. The pressure roll holders 26, 25 are on a spindle 23 rotatable in the fulcrum connection 21, there being a threaded portion 22 on the spindle for the holder 26 and a threaded portion 24 for the holder 25, the relationship between the pitches of the threaded portions 22, 24 being such as to correspond to the relation of the distances between the connection and 21 and the holders 25 and 26 respectively. Consequently, on rotation of the spindle 23, the pressure roll holders 25, 26 can be moved relatively to the fulcrum connection 21 without changing the relationship of said distances or the division of loading on said roll holders. Moving weighting lever 17 whilst maintaining a constant loading effect by the top pressure rollers.-By moving the displaceable bracket 13 within the arm 3 the position of the weighting lever 17 changes. If the lever 17 is moved forwardly the active length of the elbow lever 10, Fig. 5, is reduced and to ensure that this does not result in an increased loading effect by the weighting lever, the surface 45 of the elbow lever 10 is curved so that the direction of the increased force P, to be transmitted at the point B, is changed and acts in a forwardly inclined direction whereby its vertical component P<SP>11</SP> is less than the original vertical force P<SP>1</SP> to the required extent. Locking of drafting device.-The arm 3 when in its operating position is locked to the support 2 by means of a locking lever 5 having an arm at one end at which a roller 6 is connected, the roller 6 being received in a slot 7 of the support 2 when the device is in its locked position. Apron.-In Fig. 4 an upper apron 52 and a cradle 53 is shown associated with the pressure roll 25. The forward part of the cradle is pressed down by the rear portion 56 of a spring extending into a cavity 54 in the pressure roller holder 26. Raising foremost pressure roller holder only.- Whilst the device is in its operating position, the pressure roll holder 26 can be lifted by swinging an elbow lever 47 counter-clockwise as in Fig. 4, the lever 47 having a cranked portion 48 that engages a shoulder 51 on the pressure roll holder 26 to turn the spindle 23 in its fulcrum connection 21 about its pivotal axis 21<SP>1</SP>. This facilitates removal of the pressure roller 43 from the holder 26 in a forward and downward direction without lifting the guide and weighting arm and without taking the pressure off the remaining top rollers. A removed pressure roller is shown in dash-dot lines.