1874 H. Bushnell Forgiveness & Law iv. 237 Modes of false opinion that have no show of interlock save in their common opposition to God.

1877 W. H. Burroughs On Taxation 356 A junior patentee has the right to pay on the interlock, and a sale of the whole tract..is void as to the part within the interlock.

1928 Trans. Soc. Motion Picture Engineers 12 704 It has been necessary..to develop a motor drive equipment which will satisfactorily interlock the camera and the recording machine... It is essential that the interlock should hold..during acceleration and deceleration.

1931 B. Brown Talking Pictures ix. 206 Gaumont coupled the armature of his projector motor, and using a common power supply, obtained synchronism. To-day we use a similar type of arrangement known as the ‘electrical interlock’.

1938 Motion Picture Sound Engin. (Acad. Motion Pict. Arts & Sci.) viii. 118 Another commonly used driving system employs the Selsyn type of motor and is known as the interlock system. This is virtually an electrical gear system, whereby all the motors connected together on several separated units will start together, come up to speed at the same rate, and continue to run at identical speeds.

1938 Motion Picture Sound Engin. (Acad. Motion Pict. Arts & Sci.) viii. 119 Field rheostats for each motor are located in one place and all speeds are adjusted to maintain interlock at the estimated camera and recorder loads.

1949 J. G. Frayne & H. Wolfe Elem. Sound Recording xxiv. 477 Because the three-phase interlock windings are inter~connected with the d-c windings voltage appears on the interlock circuit as soon as the d-c leads are excited.

1962 E. L. Levitan Animation Technique i. 70/1 The process whereby the picture reel and the sound track are run and projected at the same time is called the interlock.

1934 in Webster's New Internat. Dict. Eng. Lang.

1945 Rev. Sci. Instruments 16 57/2 There are two mechanical interlocks on the controls... The selector switch is locked so that it cannot be moved unless the Variac is set to zero.

1955 Archit. Rev. 117 142/3 The most important piece of equipment associated with lift doors is the inter-lock, an electro-mechanical device which ensures that the lift cannot move until both car and landing doors are locked in position.

1958 Engineering 28 Feb. 261/3 To prevent incorrect operation, electrical interlocks are provided to ensure that the hopper can only be tilted when all the pressing rams are clear and the box is open..and that the ejection door cannot be closed until the final pressing ram has been withdrawn.

1958 Newnes Compl. Amateur Photogr. 54 It is common nowadays for even simple cameras to have a shutter-film wind interlock which prevents blank negatives or double exposures.

1963 B. Fozard Instrumentation Nucl. Reactors xiii. 170 Interlocks must be fitted to ensure that the chambers cannot be inserted under high flux conditions.

1632 W. Lithgow Totall Disc. Trav. v. 190 The branches grow so straight, and interlocking as though they were kept by Arte.

1802 W. Paley Nat. Theol. xx. 397 The attracting syrup, the rows of strong prickles, their position so as to interlock, the joints of the leaves [etc.].

1831 R. Knox tr. H. Cloquet Syst. Human Anat. (ed. 2) 84 The edges of the bones..are merely placed together without interlocking by means of denticulations.

1853 C. Brontë Villette II. xxviii. 310 I felt my fingers work and my hands interlock.

1693 J. Clayton in Philos. Trans. (Royal Soc.) 17 791 The Heads of the Branches of the Rivers interfere and lock one within another..after the manner that an Indian explained..to me, when..he clapt the Fingers of one Hand 'twixt those of the other, crying, they meet thus.]

1749 L. Evans Map Pensilv. in J. Winsor Mississ. Basin (1895) 241 This Branch [of the Susquehannah] interlocks with the Branches of Allegeny and the North Branch of Potomack.

1808 Z. M. Pike Acct. Exped. Sources Mississippi (1810) ii. 135 At five o'clock arrived at the dividing ridge between the waters of the Osage and Arkansaw..the dry branches of which interlock within 20 yards of each other.

1876 G. Bancroft Hist. U.S. (rev. ed.) II. xxxii. 300 By way of the Ottawa and the rivers that interlock with it.

1859 C. Darwin Origin of Species (1873) vi. 134 These representative species often meet and interlock.

1861 L. L. Noble After Icebergs 25 The twilight, that..neutral ground, where gloom and splendor interlock and wrestle.