Abstract:
This invention relates to a shut-off valve type oil extractor that can be screwed into an oil pan in a vehicle engine or the like, and more particularly it relates to an oil extractor of the said type which is characterized particularly in that it is locked in a shut-off state so that it won&#39;t be inadvertently opened by mechanical vibration caused during running of the vehicle.

Description:
FIELD OF THE INVENTION 
     This invention relates to an accessory part of an engine for vehicles such as passenger cars, lorries, etc., and more particularly it relates to an oil extractor which can be screwed into the drain port of the oil pan in the engine. 
     BACKGROUND OF THE INVENTION 
     Generally, for keeping proper function of an engine for vehicles, there is a need to change the lubricating oil periodically or non-periodically. For this purpose, usually a drain port is provided in the oil pan of the engine and such drain port is closed by a plug. However, according to such type of drain plug, if the plug is inadvertently removed when changing the lubricating oil, the lubricating oil in the oil pan may spill or scatter away to soil the worker&#39;s clothes or the floor of the workshop. Also, repeated use (fitting and removal) of such drain plug may result in a loose fit, and careless fixing of such plug may cause imperfect sealing to give rise to dangerous leaking of the lubricating oil. 
     For overcoming such problem, it has been attempted to adapt a shut-off valve at the drain port, but such attempt has practically ended in failure because mere incorporation of such a shut-off valve could not eliminate the risk of a chance opening of the valve by vibration of the vehicle. 
     Therefore, a change of the lubricating oil is usually practiced by inserting into the oil pan an end of an oil hose connected to a manually operatable oil pump. It is however difficult for the ordinary household to be equipped with such an oil pump, so that the oil change is usually practiced as a commercial deal at a filling station or a repair shop. This, however, involves some serious problems such as fairly high cost of oil change at such places and impracticality for a resident at a backcountry to go all the way to a repair shop for the only purpose of an oil change. 
     SUMMARY OF THE INVENTION 
     The primary object of this invention is to provide an oil extractor of a shut-off valve type that can be screwed into the drain port of the oil pan. 
     Another object of this invention is to provide an oil extractor of such a type which can be securely locked in the closed position so that it cannot be inadvertently opened by mechanical vibration of the vehicle and which, when so desired for an oil change or for other purposes, can be opened manually with no need to use any specific tool therefore. 
     Still another object of this invention is to provide an oil extractor of the described type which can be supplied at a cost almost equal to or even lower than the charge for labor (for oil change) at the repair shop or such. 
     According to the present invention, these objects can be accomplished by an oil extractor for vehicle engines or the like comprising a base block whose inlet portion can be screwed into the oil pan of the vehicle engine and which is formed with an L-shaped opening in the peripheral surface of the bushing portion, a spindle rotatably positioned in said bushing portion with an end of the spindle being engaged with the valve body housed in the base block, a compression spring disposed in the bushing portion, and a manually operated handle having its inner end portion slidably engaged with the square stem portion of the spindle and placed under the action of the compression spring and also having its outer end portion passing through the opening to extend outside of the bushing portion, wherein the manually operated handle is usually locked in the inoperative position formed at a part of the opening by the compression spring. According to such an oil extractor, it is possible to extract the used lubricating oil and replace it with fresh oil by merely setting the manual handle to the open position. This allows even the ordinary vehicle operator to perform an oil change alone with ease. 
     Also, according to the oil extractor of this invention, since the valve body is usually locked in the closed position, there is no likelihood of inadvertent opening of the extractor due to vibration of the vehicle or impact applied to the vehicle body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of an oil extractor for vehicle engines or the like according to the present invention, the extractor being here shown in its open position; 
     FIG. 2 is a similar view of the oil extractor as it is shown in its closed position; and 
     FIG. 3 is an exploded perspective view of the same oil extractor. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to FIG. 1, there is shown in section a preferred embodiment of an oil extractor for vehicle engines according to the present invention. This oil extractor comprises a base block 3 formed with an inlet port 1 and an outlet port 2. The base block 3 is cast from a metal such as brass, and its plug portion has an external thread 4 for threaded engagement with the oil pan P of a vehicle engine. Formed in the base block 3 is a cylindrical valve chamber 5 in which is positioned a valve body 6, embodied herein as a spherical valve, which is secured liquid-tightly by an annular seal 8 positioned on the seat surface 7 of the base block 3 and another a annular seal 10 supported by a retainer 9 as further described later. The valve body 6, formed with a passage 11 connected to the inlet port 1 and outlet port 2 is, inserted into the base block 3 from the outlet port 2 of a large diameter and is secured in position by the thick circular retainer 9. The retainer 9 has formed centrally therein a hole 12 that can be communicated with the passage 11, and the space between the peripheral surface of the retainer and the outlet port 2 is sealed by an O-ring 14 fitted in an annular groove 13. The retainer 9 is also withheld against removal from the base block 3 by a C-shaped stopper ring 16 which can be elastically fitted in an annular groove 15 formed in the inner peripheral surface of the base block 3. 
     Said base block 3 has at its upper part a cylindrical bushing portion 17 which has formed therein a circular-sectioned stepped shaft hole 18 in communication with the valve chamber 5 and a spring housing 19. Positioned in the shaft hole 18 is a columnar spindle 20 which has at its lower end a protuberance 21 engaged in a slot 22 formed in the upper surface of the valve body 6. Thus, when the spindle 20 and the valve body 6 are assembled in position, the valve body 6 can be rotated integrally with the spindle 20. 
     The space formed between the shaft hole 18 and the peripheral surface of the spindle 20 is sealed by a seal ring 23 positioned in an annular groove provided in the peripheral surface of the spindle 20. The spindle 20 has a square stem portion 24 which extends into spring housing 19, and as best shown in FIG. 3, an L-shaped opening 25 is formed in that part of the peripheral surface of the bushing 17 which corresponds adjacent to the square stem portion 24. The opening 25 composes a guide portion 25a having the circular measure of approximately 120° and a locking portion 25b formed at an end of the guide portion 25a extending downwardly axially relative to the portion 25a. Passing through the opening 25 is a neck portion 26a of a manually operated handle 26 which has its proximal end portion axially slidably engaged with the square stem portion 24. The manual handle 26 includes a disc-shaped proximal end portion 26b having a square hole 27 centrally formed therein with a configuration corresponding to the sectional shape of the square stem portion 24, a substantially flat neck portion 26a positioned in the opening 25, and a grip portion 26c extending outside of the bushing portion 17 and inclined relative to disc end portion 26b. 
     Positioned in the spring housing 19 is a compression spring 28 having one end pressed against the surface of the proximal end portion 26b of the manual handle 26. Also positioned in the space encompassed by the compression spring 28 is a columnar insert 29 adapted to prevent removal of the spindle 20 and the manual handle 26 and spaced to constantly maintain the projection 21 in engagement in the slot 22 of the valve body 6. The insert 29 is prevented against removal from the bushing portion 17 by a disc 30 adapted to receive the other end of the compression spring 28. The disc 30 is secured to the bushing portion 17 by a C-shaped stop ring 32 elastically engaged in an annular groove 31 on the inner peripheral surface of the bushing portion 17. 
     The oil extractor for vehicle engines according to the present invention has the above-described structural setup, so that assembling of this oil extractor can be accomplished in the following way. First, the O-ring 14 is set in the annular groove 13 in the base block 3, then the valve body 6 and retainer 9 are slided down into the base block 3 from the outlet port 2, and then the stopper ring 16 is fitted in the annular groove 15. Thereafter, by adjusting the protuberance 21 with the slot 22 in the valve body 6, the spindle 20 is positioned in the shaft hole 18 from the spring housing 19 while the proximal end portion 26a of the manual handle 16 is positioned in the bushing portion 17 by passing it through the opening 25 in the base block 3, with the square stem portion 24 of said spindle 20 being fitted in the corresponding square hole 27. Then, the compression spring 28 and insert 29 are positioned in the spring housing 19 in the bushing portion 17, and after pressingly engaging the outer ends of the compression spring 28 and insert 29 against the disc 30, the stop ring 32 is secured in the annular groove 31, this completing the assembling of an oil extractor of this invention. 
     In the oil extractor of this invention, the manual handle 26 is pushed in a given downward direction by the compression spring 28, so that the disc end portion 26b is pressed downwardly stabilizing against widened annular shoulder 17a in the shaft bore 18 and the neck portion 26a of the handle 26 is normally positioned in the locking portion 25b of the opening 25. Therefore, even if mechanical vibration or impact is applied to the oil extractor, the valve body 6 maintains its closed position shown in FIG. 2, so that there is no possibility that the oil extractor be opened by chance to cause a leak of the lubricating oil in the oil pan. When performing an oil change, the manual handle 26 is slightly raised up against the force of the compression spring 28 to move the handle 26 out of the locking portion 25b of the opening 25 and then the handle is turned about 90° along the guide portion 25a of the opening 25 to keep the valve body 6 at its open position as shown in FIG. 1. 
     As apparent from the foregoing description, according to the present invention, it is possible for anyone to perform oil change by merely operating the manual handle. Also, the oil extractor of this invention, when not used, can not be opened inadvertently, and further, it can be manufactured at low cost.