Patent GB-158672-A (GB)
Title: Improvements in or relating to route indicators for vehicles
IPC: G01C21/20
Filed: 1919-11-07
Abstract: 158,672. Buckle, G. F., and Parfett, F. Nov. 7, 1919. Course-recording apparatus.-Relates to course indicating and recording apparatus of the kind having two driven members moved in directions at right-angles to each other at relative speeds depending on the course being made, one of the said members being a map &c. passing over rollers and the other member a. pointer or scriber moving over the map. According to the invention, the relative speeds of the driven members are varied by a setting-member which turns two discs having eccentric pins engaging in slotted adjusting-members by which the speeds of the driven members are controlled. The apparatus is particularly intended for use on motor-vehicles. The casing 10 is divided into two portions separated by a partition 31; the indicating-means being mounted in the one portion and the actuating-means in the other. The former comprise the rollers 13, 14, Fig. 7, on which the map &c. is mounted, and the pointer &c. 16. The rollers carry handles 33, 34 for manual setting, the roller 13 carrying also a gear-wheel 32 while the roller 14 is acted upon by the spring 39 through the gears 37, 38 to maintain the map &c. in tension. The pointer &c. 16 is carried by a bearing 19, Fig. 8, slidable along a squared shaft 23 and having a downward extension 17 formed as a nut engaging a screwed shaft 18, with which it is held in engagement by a spring 29. By depressing the finger-piece 20, the nut can be moved away from its shaft and the pointer then manually adjusted along the shaft 23. The actuating-means comprise a shaft 53, Figs. 2 and 3, driven from the roadwheels and carrying a worm 55 engaging a wormwheel 56 which operates gear 57, 58 mounted on internally squared shafts through which pass square shafts carrying the friction driving-discs 68, 70 engaging the driven discs 69, 71. The square shafts each carry two collars 80, 82 between which pass the short ends of levers 72, 73 pivoted at 74, 75 and acted on at the outer ends by springs 76, 77 so as to press the discs 68, 70 against the discs 69, 71. To disengage the drive the levers can be operated by cams 85, 86 mounted on a shaft 87 connected to a handoperable member 84 projecting through the casing. The member 84 also carries a wedgeshaped projection 92 co-operating with a. wedge 99 to control a brake member 93 coacting with a conical extension 35 of the roller 14, so that when the drive is stopped the roller is braked. The means for adjusting the driven discs 69, 71 across the discs 68, 70 comprise a manuallyoperated setting-member 109 operating two intergeared discs 112, 113. carrying eccentric pins 116, 117 arranged as shown in Fig. 5. The pins engage slots 123, 124 in members 118, 119, slidable on guides 120, 121 and carrying forks 174, 176 passing between flanges 175, 177 carried by the discs 69, 71. These discs are slidably mounted on a guide-spindle 100 and carry long gear-wheels 101, 102 meshing with wheels 103, 104 mounted on shafts 105, 107. The shaft 105 also carries a gearwheel 106 meshing with the wheel 36 on the shaft 18 while the shaft 107 carries a wheel 108 meshing with the wheel 32 on the roller 13. To compensate for the variation in the effective diameter of the roller as the map &c. is unwound, the pin 116 is carried by a nut 127 passing over a screw 128 which is mounted radially in the disc 112 and carries a pinion 127 gearing with a crown wheel 129 which is integral with a wheel 130 driven by a wheel 131 secured to a shaft 132 which also carries a wheel 133 driven by the wheel 32. To prevent rotation of the screw 128 when the wheel 109 is turned, the latter is pressed upwards by a spring 137 and is normally locked by rings 135, 136 so that it must be pressed down, thus disengaging the gears 127, 129, before it can be turned. To give an alarm when a definite point on the route is reached the pointer 16 is connected in the circuit of a bell &c. and co-operates with adjustable contacts 147, 148. A moving contact may also be moved between adjustable contacts by the motion of the map &c. to actuate the bell. To stop the drive when a predetermined length of map has been unrolled, the shaft 132 may have a threaded portion 138 on which is a non-rotatable nut 139 which can move between collars 141, 142. A similar device 46, 47, 51 may be provided to limit the rotation of the roller 14. To facilitate the setting of the wheel 109 a transparent bearing indicator 165 is mounted on a rod 166 and can be moved to any desired part of the map.