Patent GB-190900758-A (GB)
Title: Improvements in and relating to Electric Motors especially applicable for Driving Sewing Machines and the like.
Inventor: LAKE WILLIAM EDWARD
IPC: D05B69/12
Filed: 1909-01-12
Granted: 1910-01-06
Abstract: - 758. Lake, W. E., [Bissel Co. F.]. Jan. 12. Armatures and. field magnets; brush-holders; driving-arrangements ; supports.-An electric motor and its controlling-mechanism are combined into a compact structure for ready attachment to machines in which space is limited and the driving- shafts differ slightly in diameter. Figs. 1, 2, and 3 show the motor attached to the shaft of a sewing- machine in the space usually occupied by the handwheel. The spindle 1 of the motor is tubular and is provided with a self-centring bushing comprising a sleeve 56 slitted alternately from opposite ends and provided with a thread of wedge-shaped crosssection engaging a similar thread formed within the spindle 1. On rotating the sleeve 56 after a flange 57 thereon is bearing against the spindle 1, the sleeve is contracted until it bears upon the shaft 9. The field-magnet 12 having poles 15 and wound with coils 14 is secured by arms 10 to a frame 3 supported by ball bearings 7 on the spindle 1. The armature 11 is mounted on the spindle 1 by means of a clamp comprising two members 17, 18 connected by screws 21, the member 17 being provided with a projection 22 constituting a commutator support. The brushes 37 are clamped in split sockets 38 in brush-holders 32 pivoted in the stator frame, the brush-holders being of different lengths so as to give the requisite lead to the brushes. In reversing the motor, the brushholders are slipped off their pivot pins 28 and exchanged. The pivot pins 28 are provided with square or polygonal shanks 29 inserted in the fieldmagnet core, and with a collar 30 having a pin or lug 31. The brush-holders 32 have hub-portions 33 sleeved on the pins 28, and a coiled spring 35 bears at one end upon the hub and at the other end upon the pin 31. The commutator may serve as a friction wheel for rotating another part of the machine, for example a bobbin winder, which may consist.of a friction wheel 40, Fig. 2, journaled in an arm 41 and connected to the commutator either directly or through another friction wheel 42. The member 17 may revolve loosely upon the spindle 1 ; but in normal operation it is secured thereto by a dog clutch, consisting of a dog 46 pivoted to the member 18 and entering a notch 47 in a collar 44 on the spindle 1. A spring 50 holds the dog either in or out of the notch 47, a fingerknob 49 passing through the cover-plate being also provided. A reversing-switch with bridge contacts 53,54, Fig. 6, shown in their two positions by full and dotted lines is located in a recess at the top of the fieldmagnet laminae, and the recess may be closed by the name-plate of the motor. To prevent endlong movement of the shaft 9, a collar 58 having notches 59 is clamped therein, lugs 60 on the spindle 1 engaging in these notches. The controlling- mechanism is similar to that described in Specification 13,734/09, and consists of a rheostat 66 in the motor circuit and brake straps 73 applied to the faces of the rotor, both being operated by the same actuating-mechanism. The motor is carried upon a pair of feet 74 by means of crank-shaped members 75 fitting into spring sockets 77 in the stator frame, the heads 78 of the members 75 being provided with grooves receiving set-screws 79 to limit movement. The feet 74 are adjusted by moving the members 75 angularly. In fixing the motor to the driving-shaft, the rotor is locked by inserting a key 81, Fig. 3, in a slot in one of the field-magnet poles.