US3217535A

US3217535A - Pitot assembly

Info

Publication number: US3217535A
Application number: US147607A
Authority: US
Inventors: Howard S Taylor; John G Powers
Original assignee: Airguide Instrument Co
Current assignee: Airguide Instrument Co
Priority date: 1961-10-25
Filing date: 1961-10-25
Publication date: 1965-11-16
Anticipated expiration: 1982-11-16

Description

: Nov. 16, 1965 H. s. TAYLOR ETAL 3,217,535

PITOT ASSEMBLY Filed Oct. 25, 1961 2 Sheets-Sheet l Nov. 16, 1965 TAYLOR ETAL 3,217,535

PITOT ASSEMBLY Filed Oct. 25, 1961 2 Sheets-Sheet 2 United States Patent 3,217,535 PITOT ASSEMBLY Howard S. Taylor, Fox River Grove, and John G. Powers,

Wilmette, Ill., assignors to Airguide Instrument Company, a corporation of Illinois Filed Oct. 25, 1961, Ser. No. 147,607 12 Claims. (CL 73182) This invention relates to a Pitot assembly, or a velocity pressure pickup assembly, attachable to a boat as at the transom thereof for picking up velocity pressure while the boat is in motion in water for actuating a pressure sensitive marine speedometer mechanism.

It is a general object of the invention to provide a new and improved assembly of the type described.

Another object is to provide a new and improved Pitot assembly, including a bracket attachable to a boat as at the transom, a Pitot tube mounted on the bracket and adapted to extend into water when the boat is in motion for picking up velocity pressure, means supporting the tube on the bracket for movement about an axis transverse to the tube so that the latter may yield on striking objects while the boat is in motion, and means resiliently urging the tube toward a normal, operative position.

A further object is to provide an assembly of the type mentioned, including means normally releasably locking the tube in the normal, operative position so that the tube will not yield merely by pressure exerted by the Water while the boat is in motion, but may yield upon impact with an object in the water.

It is also an object of the invention to provide a Pitot assembly including a mounting bracket, and a Pitot tube supported thereon, with means normally maintaining the Pitot tube in an operative position on the bracket and resiliently yieldable to permit the tube to turn on the bracket laterally relative to the direction of boat motion upon impact with an object in the water.

Another object is to provide a Pitot assembly including a mounting bracket attachable to a boat transom, and a Pitot tube assembly mounted on the bracket and extending downwardly and rearwardly therefrom, the Pitot tube assembly including a forwardly disposed portion in the form of a knife-like edge adapted to glide smoothly through the water and shed weeds or the like due to the smooth inclined surfaces. The tube assembly is formed with a longitudinally disposed passage terrninating at the lower end of the assembly in a forwardly disposed opening approximately normal to the direction of travel and somewhat sheltered to obviate the need for wire guards or the like which might upset water flow to the Pitot tube.

Other objects and advantages will become readily apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a side elevational view, partly broken away, of a Pitot assembly embodying the principles of the present invention;

FIG. 2 is a right end elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a sectional view taken at about the line 4-4 of FIG. 1;

FIG. 5 is a sectional view taken at about the line 5-5 of FIG. 1;

FIG. 6 is an enlarged fragmentary longitudinal sectiona'l view;

FIG. 7 is an enlarged fragmentary elevational view, similar to FIG. 1, but with parts in another position; and

FIG. 8 is an enlarged fragmentary elevational view with parts in still another position.

While an illustrative embodiment of the invention is shown in the drawings and will be described in detail herein, the invention is susceptible of embodiment in 3,217,535 Patented Nov. 16, 1965 "ice many different forms, and it should be understood that the present disclosure is to be considered as an exemplification of the principles of the invention, and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Referring now to the drawings in more detail, as illustrated, a preferred embodiment of the invention includes a mounting bracket or base 10 in the form of a bell shaped molded plastic pedestal or the like having a face as at 11 adapted to abut against the rear surface of the transom of a boat. As shown herein, the base is formed with hollow spaces as at 12 in order to reduce weight. at laterally opposite sides of the base it is recessed as at 14, and the right ends of the recesses as viewed in FIG. 1 terminate in seats as at 15 formed with apertures or openings 16 therethrough for receiving screws or bolts adapted to hold the base to the boat transom.

The end of the base remote from the face 11 is formed with a bore therethrough as at 18 for housing a plunger 19 adapted for receiving at the left end (as viewed in FIG. 1) a hinge pin 21 for mounting a Pitot tube assembly 23. Plunger 19 is slidably received in bore 18, and at the right end is provided with a washer of collar as at 25 retained on the plunger by peening the end of the plunger as at 26. The collar 25 provides a. seat for a coiled spring 28 received in a chamber 29 in the base and having its opposite end seated in the base as at 30. The spring 28 relatively strongly urges the plunger 19 toward the right end of the base as viewed in FIG. 1.

Tube assembly 23, in the preferred embodiment illustrated, comprises a molded plastic body including a bifurcated hinge portion 33 including parallel extensions 33a and 33b which embrace the adjacent end of the plunger 19. Hingle pin 21 passes through the extensions 33a and 33b, through the plunger 19, and is suitably retained in position to pivotally mount the tube assembly on the plunger for movement about axis 21 which extends transversely of the tube assembly. At the same time, the plunger 19 is turnable about its own longitudinal axis. The result is that the tube assembly is resiliently pivotable to the position illustrated in FIG. 7 and resiliently turnable to the broken line position illustrated in FIG. 2 and the full line position of FIG. 8, either or both occurring upon impact of the tube assembly with an object in the water while the boat is in motion.

When the tube assembly is disposed in the normal operative position illustrated in the drawings, end faces of the extensions 33a and 33b abut against cooperating seats 35a and 35b provided on the base 10.. At the same time, a face 36 at the lower part of hinge portion 33 abuts against a seat 37 on the base 10. In FIG. 7, it will be noted that the juncture between the face 36 and the end faces of extensions 33a and 33b is in the form of a substantially right angle shoulder including an outer corner 38a and an inner corner 3812, while the juncture between the seat 37 and the seats 35a and 35b is in the form of angularly inclined surfaces 359 inclined downwardly and toward the left from a narrow horizontal lip or shoulder 40. Cooperation of the outer corner 38a with the lip 40 provides a detent means which resiliently releasably locks the tube assembly in the normal operative position against movement merely by pressure exerted as a result of motion o f the boat in the water, while still permitting pivotal movement of the tube assembly about the hinge pin 21 on impact with an object in the water. The cooperation of the outer corner 38a with the inclined surfaces 39 facilitates turning movement of the Pitot assembly about the axis of the plunger 19.

Tube assembly 23 includes a thin elongate extension having a forwardly disposed portion in the form of a knife edge adapted to slice smoothly through the water when the boat is in motion without disturbing the flow of Water to an inlet for picking up velocity pressure. A rearwardly disposed portion of the extension as at 46 is tubular in form and includes a longitudinal passage 47 therethrough. At the lower end, the passage 47 is closed as by a plug 48, and adjacent the plug an angularly disposed passage 49 connects with the passage 47 and terminates in a forwardly facing inlet opening in a sheltered surface 52 forming part of an angular recess at the juncture of knife edge 45 and a lower, generally horizontally disposed edge 53. At the upper end of the tubular portion 46, there is provided an annularly beaded extension 55 of gradually reducing diameter. The extension 55 terminates in an outlet opening adapted for connection with a pressure sensitive speedometer mechanism as by means of flexible tubing. The tapering diameter of the extension 55 facilitates connection of such tubing of various sizes and the annular beads on the extension serve to retain the tubing securely in place.

Preferably, tube assembly 63 is formed with laterally outwardly extending reinforcing webs as at 53, which diminish in width from one end adjacent bifurcated portion 33 toward the opposite end of the assembly, as seen in the top plan view of FIG. 3.

In order to insure shedding of weeds which may slide down knife edge portion 45 .or otherwise encounter surface 52, this surface is inclined downwardly and slightly rearwardly and its lateral edges as at 56 (FIG. 2) are inclined downwardly and laterally inwardly. Thus, stringy weeds caught across surface 52 and urged thereagainst by motion of the boat in water are at the same time urged or cammed down the surface to slide off and drop into the water without manual removal so that the inlet opening is not obstructed. This construction obviates the need for inclined wire guards or the like for shedding weeds which guards might upset flow to the inlet opening.

It will be understood that the Pitot assembly or velocity pressure pickup device is adapted for mounting against the rear face of a boat transom as by means of screws or b'olts passed through the bracket apertures or openings 16. When so mounted, the tube assembly 23 is adapted to extend into water with the velocity pressure passage inlet opening facing forwardly in the direction of motion to pick up velocity pressure for transmission to a marine speedometer. The tube assembly is adapted to glide smoothly through the water without disturbing the flow to the pressure pickup inlet. At the same time, the downward and rearward inclination of the tube assembly is adapted to shed weeds nicely. It is unnecessary to utilize wire guards or the like which would upset waterfiow to the Pitot inlet.

The tube assembly is normally resiliently releasably urged to and maintained in the position illustrated in full lines. The tube assembly is releasably latched or locked in the full line position by cooperation of the interfitting shoulders 38 and 40 which serve as detent means, so that movement of the tube assembly from the position shown cannot be effected merely by pressure exerted against the tube assembly due solely to motion in the water. On the other hand, the tube assembly may pivot upwardly toward the position illustrated in broken lines in FIG. 1 on impact with objects in the water, such as a floating log, to prevent damage, if such impact is su-fficient to overcome the retentive effect of the interlocking shoulders. Similarly, a glancing blow against the tube assembly may effect at once a slight upward movement to release the interlocking shoulders and an angular turning toward the position illustrated in broken lines in FIG. 2. Pivotal movement solely about the hinge pin 21 is opposed by the spring 28 and the spring is effective auto matically to return the tube assembly to normal position when the force of impact disappears. When the tube assembly is also turned about the longitudinal axis of plunger 19, one of the shoulders 33a or 33b may engage 4- the face 37 of the mounted bracket, retaining the tube assembly in the dislocated position. The assembly may be readily returned to normal position by return manual movement about the axis of plunger 19.

We claim:

1. Pitot assembly for a marine speedometer, comprising, a mounting bracket attachable to a boat transom with its longitudinal axis parallel to the length of the boat, a Pitot tube supported on the bracket in a position to normally extend into water, said tube having at the lower end thereof a forwardly facing inlet opening to pick up velocity pressure and at the upper end thereof an outlet opening for connection with a pressure sensitive speedometer mechanism, and means mounting the Pitot tube on the bracket yieldably to turn laterally about a longitudinal axis relative to the mounting bracket on striking an object in the water when the boat is in motion.

2. The combination of claim 1, including spring means for normally resiliently maintaining the tube in the normal position.

3. The combination of claim 1, including means mounting the Pitot tube yieldably on the bracket for movement about a horizontal axis transverse to said first mentioned axis to yield on striking objects in the water during motion of the boat.

4. A combination as defined in claim 1, including cooperating means on the mounting bracket and Pitot tube for releasably retaining the tube in a laterally turned position.

5. A velocity pressure pick-up device for a marine speedometer, comprising, a mounting bracket attachable to a boat and a Pitot body on the bracket including a thin elongate extension having front and rear portions inclined downwardly and rearwardly from the bracket at a substantial angle from the vertical to shed weeds while the boat is in motion, said extension front portion having a knife-like forward edge to cut smoothly through the water, said extension having a lower end edge, means providing a rearwardly extending recess in said extension at the juncture of said forward edge and said lower end edge defined in part by a forwardly facing surface having a sheltered forwardly facing inlet opening therein, and means providing a longitudinal passage through said extension and terminating at the lower end in said inlet opening for effectively admitting velocity pressure.

6. A velocity pressure pick-up device as defined in claim 5, wherein said forwardly facing surface is inclined downwardly and slightly rearwardly and has lateral edges inclined downwardly and laterally inwardly, thereby to shed weeds.

7. A Pitot assembly for a marine speedometer, comprising, a mounting bracket attachable to a boat with its longitudinal axis parallel to the length of the boat, a Pitot tube supported on the bracket in a normal position to extend downwardly and rearwardly into water, said tube having at the lower end thereof a forwardly facing inlet opening to pick up velocity pressure and at the upper end thereof an outlet opening for connection with a pressure sensitive speedometer mechanism, means mounting the Pitot tube for yieldable pivotal movement laterally about a longitudinal axis through the mounting bracket and vertically about a transverse axis through the mounting bracket upon striking an ,object in the water during movement of the boat, and a single spring means normally resiliently maintaining the tube in normal position against turning and pivotal movement.

8. The combination of claim 7, including cooperating detent means on the tube and bracket releasably locking the tube in normal position on the bracket against movement due to pressure exerted solely by motion of the tube in the water.

9. A velocity pressure pickup device for a marine speedometer, comprising, a mounting bracket attachable to a boat transom, a Pitot tube on the bracket in an operative position to normally extend into water, said tube having a forwardly facing inlet opening at the lower end thereof to admit velocity pressure, an outlet opening at the upper end thereof for connection with a pressure sensitive speedometer mechanism, and a hinge body at the upper end thereof, a longitudinally yieldable pivot pin support on the bracket, a pivot pin pivotally conmeeting the pin support and the hinge body for pivotal movement of the latter about a transverse axis, cooperating faces on the bracket and hinge body abutting when the tube is in operative position, and spring means acting against the bracket and support normally resiliently maintaining the tube in operative position.

10. The combination of claim 9, and said cooperating faces including narrow interlocking shoulder means on the hinge body and bracket parallel to the pivot pin releasably detaining the tube against movement due to pressure exerted solely by motion of the tube in water.

11. The combination of claim 9, the pivot pin support being turnable in the bracket about its longitudinal axis. 20

12. A combination as defined in claim 11 including cooperating means on the bracket and Pitot tube for releasably holding the tube in a laterally turned position when the pivot pin is turned about its longitudinal axis.

References Cited by the Examiner UNITED STATES PATENTS LOUIS R. PRINCE, Primary Examiner.

ISAAC LISANN, ROBERT L. EVANS, LEONARD FORMAN, Examiners.

Claims

1. PILOT ASSEMBLY FOR A MARINE SPEEDOMETER, COMPRISING, A MOUNTING BRACKET ATTACHABLE TO A BOT TRANSOM WITH ITS LONGITUDINAL AXIS PARALLEL TO THE LENGTH OF THE BOAT, A PILOT TUBE SUPPORTED ON THE BRACKET IN A POSITION TO NORMALLY EXTEND INTO WATER, SAID TUBE HAVING AT THE LOWER END THEREOF A FORWARDLY FACING INLET OPENING TO PICK UP VELOCITY PRESSURE AND AT THE UPPER END THEREOF AN OUTLET OPENING FOR CONNECTION WITH A PRESSURE SENSITIVE SPEEDOMETER MECHANISM, AND MEANS MOUNTING THE PITOT TUBE ON THE BRACKET YIELDABLY TO TURN LATERALLY ABOUT A LONGITUDINAL AXIS RELATIVE TO THE MOUNTING BRACKET ON STRIKING AN OBJECT IN THE WATER WHEN THE BOAT IS IN MOTION.