US2256661A - Follow-up mechanism for indicating devices - Google Patents

Description

Sept. 23, 1941.

E. BAUMANN FOLLOW-UP MECHANISM FOR INDICATING DEVICES Filed March 24, 1939 INVENTOR 5, Ba, a 07 a; 17 /7 ATTORNEY Patented Sept. 23, 1941 FOLLOW-UP MECHANISM FOR INDICATING DEVICES Ernst Baumann, Berne, Switzerland, assignor to Hasler A.-G. Werke fiir Telephonie und Prazisionsmechanik, Berne, Switzerland, a corporation of Switzerland Application March 24, 1939, Serial No. 264,046 In Switzerland March 31, 1938 7 Claims.

The invention relates to a follow-up mechanism in an indicating device particularly in a device for indicating and recording the charging pressure of an internal combustion engine in relation to the tachometer.

According 'to the invention a flexible diaphragm or composite diaphragm is exposed to the fluid pressure to be recorded and moves a member in the path of an oscillating driver actuating the recording mechanism, so that the travel of the driver, in one direction, is variably limited by the said moving member. The action of the recording mechanism is, consequently, dependent on the fluid pressure, but that pressure is not used for actuating the recording mechanism.

An example of apparatus according to the invention is shown in the accompanying drawing, in which Fig. 1 is a vertical section thereof, partly broken away, and.

Fig. 2 is a perspective view of the follow-up mechanism.

The casing I shown in the left hand side of Fig. 1, partly broken away is divided by a horizontal partition 2 into two chambers 3 and 4. The upper chamber 4 contains the recording device, which may be of any convenient construction, and of which only the record sheet 5 is shown. Mechanism for actuating the recording implement is contained in the chamber 3. The record sheet 5 may be moved at a constant speed, e. g. by means of a clockwork, or at a speed varying with that of a driving shaft, e. g. the axle of a vehicle, according to the purpose for which the instrument is used.

Joined to the casing l is a cylindrical casing 6. The dividing wall between the casings has an opening 23 with a circular cover I on one side and a cover 22 on the other side, and opposite this opening the casing 6 has an opening with a gas-tight cover 8, held in position by a screw ring 9. The cover 8 has an inwardly directed recess, and outside it there is an external cover I!) with an outwardly directed recess forming a compartment II, in which there are two bevel gears l2, l3 for driving spur gears l4, IS in the cavity in the cover 8. A nipple I6 is screwed into the upper part of the cover In, and projects through the cover 8. This nipple serves for joining the pressure pipe to the instrument. This may, for example, be a pipe connected to the induction pipe of an internal combustion engine. The pocket II has a tubular extension l0 with a gland I'l therein for a shaft l8 carrying the gear l2. The shaft has a gudgeon IQ for coupling therewith a driving shaft, which may for example be driven by the axle of a vehicle. The gears l3 and I4 are fixed to a shaft passing through a hollow shaft 2| between the covers I and 8. Between the covers 1 and 22 this shaft drives the actuating mechanism of a speedometer, not shown in the drawing.

The gear wheel I5 is fixed to a shaft 25, which carries inside the casing 6 a disk 26, which carries a cam roller 27. Supported by a bar 28 in the casing 6 are two elastic diaphragm boxes 29, but there may be more than two such boxes. A link 36 connects the bottom of the lower box to an arm 3| on a shaft 32 mounted in bearings in the covers 1 and 3, and to this shaft is fixed also a curved arm 33 having a finely serrated convex edge. A detector lever 34 mounted on sleeve 52 on shaft 38 has a laterally projecting tooth 35 in the path of the curved arm 33 and a lever 31 also mounted on sleeve 56 is held by a spring 36. in contact with the roller 21, so that at intervals the detector lever 34 is removed from contact with the curved arm 33, and the tooth 35 is disengaged from the serrated edge of that arm, which is thus enabled to assume a new position if the fiuid pressure has changed.

The shaft 38 parallel to shaft 25 has a toothed quadrant 39 fixed thereto, and a coiled spring 40 acts on this quadrant so that when the quadrant is released from a detent to be described hereinafter it is rotated till an abutment 4| projecting laterally therefrom strikes an abutment 34 onthe detector lever 34. The position of the quadrant at this time consequently depends on the pressure which has been acting on the diaphragm boxes during the preceding interval of time.

The quadrant is locked in the position to which it is moved by the spring, there being for this purpose a lever 42 having a plurality of teeth, held by a spring 43 in engagement with a toothed wheel 44 fixed to a pinion 45 in mesh with the quadrant 39. The teeth of the wheel 44 and the detent lever 42 are of such configuration that the detent lever restrains the wheel from rotating in one direction only. The lever 42 is connected with a lever arm 46 resting on a cam 41 rotating with the disc 26. When the lever is lifted by the cam 41 the lever 42 releases the wheel 44 and quadrant 39. The shaft 38 has fixed thereto a quadrant 48 for actuating, by means of gears 49, 49*, a vertically reciprocatable rack 56 having at its upper end the style (not shown) which records the fluid pressure or degree of vacuum on the sheet 5.

At each revolution of the disc 26 the detector lever 34 is disengaged from the curved arm 33,

, which is thus able to assume a new position,

whereupon the lever 34 returns into" engagement therewith. The cam 41 and lever 46 then disengage the lever 42 from the wheel 44 and release the quadrant 39, which assumes a posi'-' spring 40, so that the friction incidental to the" movement of that style is overcome by the spring alone and does not in any .way react on the setting of the mechanism actuated by, the fluid pressure. 7

The instrument described may with advantage, be used in connection with aircraft, for the purpose of obtaining a continuousrecord of charging pressure or fuel consumption concurrent with a record of speed. j a

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. A' follow-up mechanism comprising an elastic diaphragm device responsive to fluid pressure, an oscillating detector, a rotatable driving element for said detector, an abutment adjusted by said diaphragm device in the path of said detector limiting the movement of said detector in one direction, style actuating mechanism for recording the fluid pressure and an oscillating driver actuated by said driving element for actuating said style actuating mechanism, said detector limiting the movement of said driver in one direcabutment in the path of a quadrant which is in- Y termittently releasedand is then moved by a spring'against said abutment thereby actuating said style actuating mechanism.

5. A follow-up mechanism as set forth in claim 1v in which said abutment comprises a curved arm on a shaft rotatable by said diaphragm de vice and said detector comprises a lever carrying an abutment in the path of a quadrant which is intermittently released and is then moved by a spring against said abutment thereby actuating said style actuating mechanism, said quadrant f being locked by a ratchet'device which is put out 7 of action by a lever when said detector engages 'said first-named abutment.

,tic diaphragm device responsive to fluid pres- 6. A follow-up. mechanism comprising an elassu're, an oscillating detector, a rotatable driving element for said detector, an abutment adjusted by said diaphragm device in the path of said detector limiting the movement of said detector in one direction, style actuating mechanism for' recording the fluid pressure, an oscillating driver actuating by said driving element for actuating said style actuated mechanism, said detector limiting the movement of said driver in one direction, said adjustable abutment being a curved arm on a shaft rotatable by; said diaphragm device, a quadrant, saiddetector being a lever carrying an abutment in the path: of said quadrant which is intermittentlyreleased and then actuated by a'spring up to said, abutment thereby actuating saidstyle actuating mechanism, said quadrant being locked ,byha' ratchet device which is disabledwhen said, detector engages said first-mentioned adjustable abut,-

ment. I a 7. A follow-up mechanismcomprising an elastic. diaphragm device responsive to fluid pressure, an oscillating detector,'a rotatable driving element for, said detector, an abutment adjusted by said diaphragm device in the path of said detector limiting the movement or'saidldetector in one direction, style actuatingmechanism for recording the fluid pressure, an oscillating driver actuating by said driving elementfor actuating said style actuated mechanisnr'said 'detector limiting the movement, of said driver in one direction, said adjustable abutment comprising a shaft rotatable by said diaphragm device and a curved arm thereon, a quadrant, said detector comprising a lever carrying an abutmentin the path of said quadrant which is inter mittently released and it is 'then moved by a spring up, to said abutment thereby actuating.

said style actuating mechanism, a ratchet de' vice for locking said quadrant and a lever fordisabling said ratchet device when said detectorengages said first-mentioned adjustable abuts ment.

ERNST BAUMANN.

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