GB685741A - Improvements in folding laryngoscope and angularly adjustable and detachable joint therefor - Google Patents

Abstract

685,741. Surgical optical instruments. WELCH ALLYN, Inc. May 15, 1951 [Feb. 12, 1951], No. 11314/51. Class 81 (ii). A laryngoscope comprises a handle and a blade interconnected by a hinge joint including complemental relatively rotatable members for enabling the blade to be angularly adjusted relative to the handle, shiftable means for locking the handle and blade in selected adjusted positions and means for releasably preventing the shiftable means from being shifted in one direction. A blade 2 carried by head member 4 is connected to a handle 1 by a hinge joint 3. The hinge joint 3 comprises a member 6' integral with a base portion 6 of the handle 1 and having a portion 14 which receives a complementary member 5 integral with the head member 4 of the blade 2, the two members 5, 6' being held together by pins 9<SP>1</SP> arranged in slots in such a way that the complementary members may only be separated on rotation when in one particular relative position. A plunger 17 attached to a button 24 is fitted with splines 18 which slidably engage splines 16 on the member 6' attached to the base 6 and splines 18 which engage splines on the member 5 integral with the head member 4. The plunger 17 is normally held by a spring 27 so that the two sets of splines engage to lock the members 5, 6<SP>1</SP> relative to one another and hold the blade 2 and handle 1 in any desired relative position. When the plunger 17 is pressed inwardly by the button 24 the splines 18 are disengaged from the splines on the member 5 integral with the head member 4 and are replaced by a narrowing 19 of the plunger 17 so that relative rotation of the members 5, 6<SP>1</SP> is allowed and readjustment of the blade 2 and handle may be effected. The skirt of the button 24 is provided with a segmental recess 30 in the region of the base member 6 to allow depression of the button 24. Inadvertent depression of the button 24 is prevented by a cam lock 31 or in an alternative construction (not shown) by rotation of the button 24 so that its segmental recess 30 is displaced from the region of the base member 6. A lamp 35 mounted on the blade 2 is illuminated for at least one blade position in which a conducting ball (not shown) mounted in the head member 4 is in contact with a conducting strip (not shown) which is surrounded by insulating material 44 on the surface of the hinge member 6' which is integral with the base member 6, the conducting strip being connected with a battery 36 in the handle 1 or a mains supply.