Abstract: A video tape recorder having a tape tensioning mechanism for tensioning a magnetic tape drawn out of a tape cassette. The tape tensioning mechanism has a tensioning arm rotatably mounted on a movable Chassis, a tensioning pin for contacting the tape to tension the tape when the tape has been loaded in a predetermined tape path, a tightening lever movably mounted on the movable chassis, and a tension spring for urging the tensioning arm in a direction of rotation to bring the tensioning pin into contact with the tape. A pusher is fixedly mounted on a fixed chassis for pushing the tightening lever to tighten the tension spring substantially at the same time that the magnetic tape is loaded in the predetermined tape path. When the magnetic tape is not loaded in the tape path, the tightening lever is released from the pusher to loosen the tension spring.

Abstract: A tape recorder and reproducer machine has a rotatable head drum carrying a plurality of heads for recording a signal onto a cassette-type magnetic tape and for reproducing the signal recorded on a cassette-type magnetic tape. The machine comprises a cassette chamber for receipt of a tape cassette, a protective member movable between first and second positions, and a drive for moving the protective member to the first position between the cassette chamber and the head drum to protect the head drum from damage when the tape cassette is to be placed into or discharged from the cassette chamber. The drive moves the protective member from the first position to the second position allowing access from the head drum to the magnetic tape when the tape cassette is received in the cassette chamber.

Abstract: A tape cassette including a cassette case; a pair of rotatable tape reels accommodated in the cassette case for winding a magnetic tape therearound; a mouth section formed between and front of the tape reels in the cassette case for receiving a head drum and the like of a recording/reproducing device; a mechanism for allowing pivotal movement of the tape reels to rear corner portions of the cassette, whereby when the tape cassette is loaded into the recording/reproducing device, the tape reels are pivotally moved from an initial position to a retracted position defined at the rear corner portions of the cassette case, thereby expanding the mouth section; and a pair of reel retainers pivotably supported in the cassette case for rotatably supporting the tape reels, respectively, each of the reel retainers having a bottom wall formed with a positioning hole adapted to engage a positioning member provided in the recording/reproducing device.

Abstract: The separation material for separating and recovering a blood coagulation factor comprises a porous matrix having linked thereon one or more ligands each consisting of a radical exhibiting an affinity for the blood coagulation factor to be recovered, said matrix having a specific surface area of at least 1.5 m.sup.2 per milliliter of the separation material with respect to pores having diameters of at least 0.1 .mu.m and being derived from a porous particulate material having an exclusion limit molecular weight of at least 1.5.times.1.sup.6 as determined with polyethylene glycol. The separation material is prepared by the process steps of subjecting a porous particulate material having an exclusion limit molecular weight of at least 1.5.times.10.sup.

Abstract: A novel ion exchanger useful for universal ion-exchange purposes and, in particular, for ion exchanger for ion-exchange chromatography is proposed, said novel ion exchanger being obtained by introducing radicals of one or more ion-exchangeable groups into cross-linked glucomannan beads by a chemical treatment thereof. Such ion exchanger beads are superior in the compressive strength and permit a high flow rate of the liquid to be subjected to ion exchange through an exchange column packed with them.