Patent GB-559160-A (GB)
Title: Improvements in keyboard mechanism
IPC: B41B27/04
Filed: 1942-07-28
Abstract: 559,160. Type-bar-making machines. MERGENTHALER LINOTYPE CO. July 28, 1942, No. 11333/43. Convention date, Sept. 24, 1941. Divided out of 559,147. [Classes 100 (iii) and 100 (iv)] [Also in Group XXIV] Keyboards ; driving-mechanism.-Relates to (1) power-mechanism for operating the escapementreeds, and (2) means for permitting the keyboard to be moved into a forward position for servicing and repair. (1) The power-mechanism comprises a series of operating-cams, each of which can be locked to a rotating shaft for one revolution by a clutchmember movable longitudinally of the shaft. The escapement-reeds F, Fig. 4, are operated by rockshafts F<SP>2</SP> from two sets of reeds F<SP>3</SP> actuated by levers F<SP>15</SP>, as described in specification 559,14<SP>7</SP>. The levers F<SP>15</SP> are operated through spring thrust-members H<SP>4</SP> and levers H<SP>14</SP> from two banks of cams H<SP>15</SP> loosely mounted on rotating shafts H<SP>16</SP>. Each cam is prevented from moving axially on its shaft by a pair of washers H<SP>18</SP>, H<SP>19</SP>, Fig. 5, having internal projections H<SP>29</SP>, which can slide in axial grooves H<SP>26</SP> in the shaft. After assembly of the cams and washers, the washers are turned slightly, so that their projections H<SP>29</SP> leave the axial grooves H<SP>26</SP> and enter peripheral grooves H<SP>28</SP> in the shaft, whereby axial movement is prevented. The washers are then locked against rotation by a pin H<SP>22</SP>, which is passed through notches in the washers and through an axial groove in the shaft. A clutch-member H<SP>20</SP> having teeth H<SP>21</SP> is splined on the shaft adjacent to each cam. A spring- biassed yoke member H<SP>23</SP> tends to move the clutchmember axially, so that its teeth engage projections H<SP>42</SP> on the cam, but the clutch-member is normally held out of engagement by a lug H<SP>37</SP> on the cam, which engages the yoke-member. The cams are normally held against rotation by levers H<SP>39</SP>, Fig. 4, which engage their lugs H<SP>37</SP>. When a key-lever E<SP>2</SP> is depressed, the corresponding lever H<SP>39</SP> releases its cam, which is initially turned by the drag of the rotating washers H<SP>18</SP>, H<SP>19</SP>. The lug H<SP>37</SP> then escapes from the yoke-member, and the clutch-member H<SP>20</SP> is moved axially by its spring, so as to engage and positively rotate the cam. Towards the end of one revolution, the lug H<SP>37</SP> pushes back the yoke H<SP>23</SP> and disengages the clutch. The cam continues to turn under the action of the washers until arrested by the lever H<SP>39</SP>, which has returned to initial position. The mechanism is enclosed in housings H<SP>43</SP> containing oil which reduces wear and increases the drag of the washers. (2) The keyboard E, Fig. 18, is guided for fore-and-aft movement by bars E<SP>8</SP>, which pass between rollers E<SP>9</SP> mounted on a stationary supporting-frame E<SP>15</SP>. Upon withdrawal of a locking- bolt, the keyboard can be drawn forwards, and after detachment of a retaining-washer, can be removed altogether. Before being moved, the keyboard is lowered, in order to disengage it from the escapementoperating levers F<SP>15</SP>. For this purpose, the supporting-frame E<SP>15</SP> is hinged at its rear end and is supported at the front on cams E<SP>31</SP>, which can be turned by means of a handle E<SP>27</SP> in order to lower the frame. The withdrawal of the locking-bolt shifts the driving- belt E<SP>47</SP> of the power-mechanism from a two-grooved pulley E<SP>41</SP> on to an idler pulley E<SP>51</SP>, which is normally in alignment with it.