Ratchet wrench head with lubrication port

Information

  • Patent Grant
  • 6305246
  • Patent Number
    6,305,246
  • Date Filed
    Wednesday, December 22, 1999
    25 years ago
  • Date Issued
    Tuesday, October 23, 2001
    23 years ago
Abstract
A lubrication port is placed in the yoke of a pneumatic powered ratchet wrench or the head of a hand powered ratchet wrench. The lubrication port is placed so that it intersects with the teeth formed on the circumference of the bore formed in the yoke or the ratchet head which come in contact with the teeth formed on the outer ends of the pawl(s) of a ratchet mechanism. This allows for the application of lubricants, preferably grease, to the area of engagement between the teeth formed on the circumference of the bore of the yoke, ratchet head or ratchet mechanism and the teeth formed on the outer ends of the pawl(s) of a ratchet mechanism. Application of lubricants through the lubrication port of the present invention also allows for lubrication of the moving components of the ratchet assembly. Moreover, in a pneumatic powered ratchet wrench the lubrication port allows for application of lubricants to the drive bushing and crank of the wrench. Optionally, this port may be bored to apply lubricants directly to the drive bushing and crank of a pneumatic wrench. Preferably, a grease fitting is affixed within the inlet portion of the lubrication port of the present invention to further aid in application of lubricants.
Description




FIELD OF THE INVENTION




The present invention is generally a lubrication port formed within the head of a ratchet wrench. More specifically, the present invention is a lubrication port within a yoke or ratchet wrench head for the application of grease or other lubricants to the area of engagement between the teeth formed on the pawl(s) of the ratchet mechanism of the wrench and the teeth formed within the yoke or head of a ratchet wrench.




BACKGROUND OF THE INVENTION




Pneumatic and hand powered ratchet wrenches are well known in the art. Such wrenches typically consist of a ratchet mechanism having a shift lever and a drive square for receiving a socket. The shift lever is coupled to at least one pawl which is pivotally mounted and has teeth formed on its outer ends. The pawl(s) are mounted in a manner to engage teeth formed on the inner surface of the yoke, ratchet head or teeth on the outer circumference of the ratchet mechanism. Rotation of the shift lever to one position urges one end of the pawl or pawls into engagement with the teeth of the yoke, ratchet head or ratchet mechanism. The pawl or pawls prevent rotation of the drive square and socket in one direction while allowing rotation in the opposite direction. Switching the shift lever to the second position pivots the pawl(s) causing the engaged teeth on the pawl(s) to become disengaged while causing the teeth on the opposite end of the pawl(s) to be urged against and engage with the teeth of the yoke, ratchet head or ratchet mechanism.




It is beneficial to lubricate the area of engagement between the teeth formed on the yoke, ratchet head or ratchet mechanism of the wrench and teeth formed on the ends of the pawl(s) to prevent excessive wear of these teeth and to allow the pawl(s) to pivot more easily within the bore of the yoke. In the past, this was accomplished by removing the ratchet mechanism and applying grease or other lubricants to the ratchet mechanism, the pawl(s) and the teeth of the yoke wrench head or the ratchet mechanism.




More recently, manufacturers have placed a grease fitting for application of lubricants in the shift lever of a self-contained ratchet mechanism. However, grease fittings within the self-contained ratchet mechanism do not supply the necessary lubrication directly to the area of engagement between the teeth formed on the pawl(s) and the teeth formed in the inner surface of the yoke of the wrench or wrench head, or the teeth formed on the outer circumference of the ratchet mechanism.




Thus, there is a need to provide a ratchet wrench with a port formed within the yoke of a pneumatic wrench or the ratchet head of a hand wrench for application of lubricants to the area of engagement between the teeth formed on the outer ends of the pawl(s) of the wrench and the teeth formed in the inner surface of the yoke, ratchet head or the teeth formed on the outer circumference of the ratchet mechanism.




SUMMARY OF THE INVENTION




It is a general object of the present invention to provide a yoke having a lubrication port for use with a ratchet wrench which is usable with any number of different ratchet mechanisms and thus different pneumatic ratchet wrenches.




It is another object of this invention to provide a yoke having a lubrication port that allows for the application of lubricants to the area of engagement between the teeth formed on the pawl(s) and the teeth formed on the inner surface of the yoke of a pneumatic ratchet wrench.




It is another object of this invention to provide a yoke having a lubrication port that allows for the application of lubricants to the ratchet mechanism and other moving components of a pneumatic ratchet wrench.




It is yet another object of the present invention to provide a yoke having a lubrication port having a grease fitting affixed within the port for application of grease to the area of engagement between the teeth formed on the pawls and the teeth formed on the inner surface of the yoke, to the ratchet mechanism and to other moving components of a pneumatic ratchet wrench.




It is a further object of the present invention to provide a hand operated ratchet wrench with a lubrication port that allows for the application of lubricants to the area of engagement between the teeth formed on the pawl(s) and the teeth formed on the inner surface of the ratchet head or teeth formed on the circumference of the ratchet mechanism.




It is still another object of the present invention to provide a ratchet wrench with a lubrication port which allows for application of lubricants to the ratchet mechanism and other moving components of the ratchet wrench.




It is yet another object of the present invention to provide a ratchet wrench with a lubrication port having a grease fitting affixed within the port for application of grease to the area of engagement between the teeth formed on the pawls and the teeth formed on the inner surface of the ratchet head or teeth formed on the circumference of the ratchet mechanism.




These and other objects of the present invention are accomplished by having a port originating on the outer surface of the yoke or ratchet head and terminating at the inner surface of the yoke or ratchet head, so that the port communicates with the bore formed in the yoke of a pneumatic powered ratchet wrench or the ratchet head of a hand powered ratchet wrench. The terminal end of the port may intersect with a number of the teeth formed on the inner surface of the yoke or ratchet head bore or may terminate in the ratchet head bore adjacent to teeth located on the ratchet mechanism contained therein. The port acts as a channel to allow grease or other lubricants to be applied to the teeth formed on the pawl(s) of the ratchet mechanism and the teeth formed on the inner surface of the yoke or ratchet head bore or the circumference of the ratchet mechanism and lubricate the same. In the preferred embodiment, a grease fitting is placed within the port of the yoke to allow for ease of application of the lubricants and to retain the lubricants within the port and wrench assembly.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of pneumatic ratchet wrench having a yoke with a lubrication port;





FIG. 1A

is an exploded perspective view of having a yoke with a lubrication port;





FIG. 2

is a perspective view of the head portion of a pneumatic powered ratchet wrench with the yoke of the present invention removed;





FIG. 3

is a perspective view of the yoke of the present invention within the head portion of a pneumatic powered ratchet wrench;





FIG. 4

is a perspective view of the yoke of the present invention;





FIGS. 5 and 5A

are perspective views of the yoke with a lubrication port which extends to the drive bushing journal;





FIG. 6

is a bottom elevational view of the yoke with a lubrication port which extends to the drive bushing journal.





FIG. 7

is a sectional view taken along line


7





7


of

FIG. 6

illustrating the yoke of

FIG. 6

having a lubrication port which extends to the drive bushing journal.





FIG. 8

is a perspective view of the yoke with a lubrication port having a grease fitting at the inlet end of the port.





FIGS. 9 and 9A

are perspective views of a hand powered ratchet wrench having a lubrication port.





FIG. 10

is an exploded perspective view of a hand powered ratchet wrench having a lubrication port and the ratchet mechanism having teeth formed on its circumference.





FIG. 10A

is a perspective view of a hand powered ratchet wrench having a lubrication port with the ratchet mechanism removed.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.




Referring to

FIGS. 1 and 1A

, there is shown a pneumatic powered ratchet wrench as is known in the art shown generally at


10


, having a head portion


11


and a handle portion


13


. Head portion


11


contains a ratchet mechanism


12


having a shift lever


14


, a drive square


18


and pawl


15


. It is to be understood that ratchet mechanism


12


, may have more than one pawl


15


mounted therein. Ratchet mechanism


12


fits within a yoke


16


in order to allow for rotation of the drive square


18


. Yoke


16


and in turn, ratchet mechanism


12


are driven by drive mechanism


26


, which consists of a drive bushing


27


and a crank


25


. Drive mechanism


26


is powered by a motor located in the housing


22


of the wrench


10


. Although a pneumatic motor is described as the preferred power source, and is well known in the art, other motors such as electric motors, can also be used to drive the ratchet wrench. The end of handle portion


13


contains a compressed air inlet port


24


, which connects to a compressed air supply by various means known in the art. An actuation button


20


is located between air inlet port


24


and housing


22


, which allows the operator to actuate the pneumatic motor, the drive mechanism


26


and the ratchet mechanism


12


. This actuator may be a button as shown, or a lever or any other type of throttle valve activating device known and used in the art.




Now referring to

FIG. 4

, there is shown a first embodiment of the present invention. Yoke


16


is shown removed from the head of the pneumatic ratchet wrench of FIG.


1


. Yoke


16


has teeth


34


formed on its inner surface and a drive bushing journal


36


for engagement with the drive bushing


27


of the wrench. Yoke


16


further has a lubrication port


30


formed through outer surface of yoke


16


and into bore


38


of yoke


16


. Port


30


has an inlet


31


on the outer wall of yoke


16


for accepting the desired lubricant and terminates at outlet


32


which intersects with teeth


34


for application of lubricant to teeth


34


on the inner surface of yoke


16


.




Port


30


allows for application of lubricants to the area of engagement between the teeth formed on the outer ends of the pawl(s) of ratchet mechanism


12


and teeth


34


formed on the inner surface of yoke


16


. Although various lubricants can be applied through port


30


, grease provides better and longer lasting lubrication while also having better adhesive properties than other lubricants such as oils. Applying grease to the area of engagement between the pawl(s) of the ratchet mechanism


12


and teeth


34


improves the operation of the wrench and prevents excessive wear of both the teeth formed on the outer ends of the pawl(s) and teeth


34


formed on the inner surface of the yoke


16


thereby decreasing maintenance and repair of the wrench


10


and increasing the life of the pneumatic wrench.




The grease or other lubricant is applied to all of teeth


34


through the action of the pawl(s) of the ratchet mechanism traveling about the circumference of bore


38


. Application of additional lubricant to port


30


causes lubricant to be applied to the moving components of the ratchet mechanism


12


. When the ratchet wrench has been properly lubricated, application of lubricant to port


30


is stopped.




In

FIGS. 2 and 3

, head portion


11


of a pneumatic powered ratchet wrench is shown with the ratchet mechanism removed. Head portion


11


has an upper ear


28


and a lower ear


29


. Each of the ears


28


,


29


have a scallop


13


formed on the interior surface of cars


28


,


29


to allow for placement of the drive bushing


27


and crank


25


. It is not necessary that the yoke of the present invention be used in conjunction with a ratchet head as shown in

FIGS. 2 and 3

, however use of such a ratchet head with the yoke


16


of the present invention allows lubricant applied via the lubrication port


30


to travel through scallops


13


and lubricate the crank


25


and drive bushing


27


of the pneumatic powered ratchet wrench. After the crank


25


and the drive bushing


27


of the pneumatic powered ratchet wrench are positioned into the housing of the pneumatic wrench, the yoke


16


is placed between the ears


28


,


29


of the head


11


in a manner that the drive bushing journal


36


comes into contact with and can be driven by the drive bushing


27


and crank


25


. Lubricant is applied through lubrication port


30


and as ratchet mechanism


12


travels around the circumference of bore


38


, lubricant is forced into scallops


13


and provides lubrication to the crank


25


, the area of engagement between the crank


25


and drive bushing journal


36


, and the area of engagement between drive bushing


27


and drive bushing journal


36


.




As shown in

FIG. 8

, port


30


may optionally have a grease fitting


37


affixed within the inlet


31


of port


30


. As the grease fitting interfaces with the nozzle of a grease gun, the fitting aids in application of the grease into the port


30


. The fitting also aids in retention of the grease within port


30


and bore


38


. Fitting


37


can be any one of various types of grease fittings commercially available or known and used in the art.




Now referring to

FIGS. 5

,


5


A and


6


, a second embodiment of the yoke of the present invention is shown. Like the first embodiment, yoke


116


has teeth


134


for engagement with the teeth formed on the outer ends of the pawl(s) of the ratchet mechanism and a drive bushing journal


136


which contacts and is driven by the drive mechanism


26


, of the pneumatic ratchet wrench as shown in FIG.


1


A. This embodiment also comprises a yoke


116


with a first and second lubrication port. The first lubrication port


130


having an inlet


131


and an orifice


132


. Orifice


132


acts as an outlet for lubrication placed within first lubrication port


130


through inlet


131


, and an inlet for lubrication to pass through first lubrication port


130


by orifice through second lubrication port


135


and through outlet


133


. The first and second lubrication ports of yoke


116


arc in direct fluid communication with each other by means of shared common orifice


132


. Therefore, a portion of grease or other lubrications introduced into inlet


131


of lubrication port


130


exits yoke


116


at orifice


132


, while a portion of the lubricant will be forced through the second lubrication port


135


to exit at outlet


133


. Due to the typically tight clearances between the yoke


116


and the ratchet mechanism


12


, displacement of lubricant through second lubrication port


135


and outlet


133


is further enhanced when the ratchet wrench


10


is assembled having ratchet mechanism


12


adjacent to orifice


132


, assisting in directing lubricant down second lubrication port


135


. Outlet


132


allows for application of grease or other lubricants to the area of engagement between the teeth


134


formed on the inner surface of yoke


116


and the teeth formed on the outer ends of the pawl(s) of the ratchet mechanism of the wrench. Outlet


133


allows for direct application of grease or other lubricants to the drive bushing and drive crank of the pneumatic wrench with which yoke


116


is used.




As described in association with port


30


and yoke


16


of the previous embodiment, port


130


may optionally have a grease fitting affixed within inlet


131


of port


130


.




Now referring to

FIG. 9 and 9A

, there is shown a third embodiment of the present invention. This embodiment consists of a hand operated ratchet wrench


210


as is known in the art having a head


216


with a bore


238


formed within it which receives a ratchet mechanism as herein before described. On the outer circumference of bore


238


are formed teeth


234


which engage the teeth formed on the outer ends of the pawl(s) of a ratchet mechanism which is inserted into the head


216


of wrench


210


. Within head


216


is lubrication port


230


with an inlet


231


and an outlet


232


.




Grease or other lubricants pass through lubrication port


230


and are applied to the area of engagement between teeth


234


and the teeth formed on the pawl(s) of the ratchet mechanism as the ratchet mechanism rotates within bore


238


. Application of lubricant through port


230


also provides for lubrication of the moving components of the ratchet mechanism.




Like the yoke of the previous embodiments described above, lubrication port


230


may have a grease fitting affixed within the outer end of the port


216


to provide the advantages as described herein.




In

FIGS. 10 and 10A

is shown yet another embodiment of the present invention. This embodiment consists of a hand operated ratchet wrench


310


having a head


316


within which is formed two intersecting cylindrical bores creating one figure-eight shaped bore


338


which accepts ratchet mechanism


312


. Ratchet mechanism


312


has teeth


334


formed on its outer circumference and drive square


318


extending from the center of ratchet mechanism


312


for engaging a socket. Pawl


315


is mounted within the smaller section of bore


338


and is pivotally connected to the shift lever (not shown). In use, teeth


334


come into contact with teeth formed on the outer ends of pawl


315


to allow for selective rotation of ratchet mechanism


312


. Within head


316


is lubrication port


330


having an inlet


331


and an outlet


332


.




Grease or other lubricants are applied through port


330


and onto teeth


334


. As teeth


334


revolve within bore


338


, lubricant is applied to the teeth formed on the outer ends of pawl


315


. As with the previous embodiments, port


330


may have a grease fitting affixed within outlet


332


to provide the advantages as herein described.




It is also contemplated that more than one lubrication port may be provided in the embodiments of the ratchet yokes and wrenches described above. Moreover, each of these lubrication ports may be formed having more than one outlet placed along the circumference of the bore of the ratchet head or yoke. Further, the outlets of the lubrication port may be formed in different diameters and/or sizes to allow for application of different amounts of lubrication to different areas of the ratchet wrench as necessary.




Other embodiments and variations of the preferred embodiments described herein will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the above description.



Claims
  • 1. A powered ratchet wrench comprising:a body having a handle portion and a head portion; a drive motor; a ratchet mechanism comprising at least one pawl having a plurality of teeth; said head portion having a bore therein for receiving said ratchet mechanism, and having a plurality of teeth which engage the plurality of teeth of said at least one pawl; a drive mechanism positioned within said body adjacent said bore; a lubrication port having an inlet and at least one outlet, said lubrication port communicating lubricant between the outer surface of said head portion and said bore to allow for application of lubrications to the area of engagement between the plurality of teeth of said at least one pawl and said head portion, and concurrently to said drive mechanism position in said body.
  • 2. A powered ratchet wrench as recited in claim 1, further comprising a grease fitting affixed within the inlet of said lubrication port.
  • 3. A powered ratchet wrench as recited in claim 1, wherein said lubrication port further comprises a second outlet.
  • 4. A powered ratchet wrench as recited in claim 1, wherein said wrench is powered by a pneumatic motor.
  • 5. A powered ratchet wrench as related in claim 1, wherein said lubricant port comprises an inlet and at first outlet communicating between said inlet and said bore, and a second outlet communicating between said inlet and said drive mechanism.
  • 6. A powered ratch wrench as recited in claim 1, further comprising a second lubrication port having an inlet and at least one outlet communicating between said bore and said drive mechanism to allow for application of lubricants to said drive mechanism.
  • 7. A powered ratch wrench as recited in claim 6, wherein said first and second lubrication ports intersect at the outlet of said first lubrication port to facilitate distribution of lubrication from the inlet of said first lubrication port to the outlet of said first lubrication port and the outlet of said second lubrication port.
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Number Name Date Kind
2217740 Ehnts Oct 1940
2483544 Jacobsen Oct 1949
3498186 Northcutt Mar 1970
3529498 Northcutt Sep 1970
3614182 Rozentals Oct 1971
4116093 DePagter Sep 1978
4346630 Hanson Aug 1982
4374480 Diaz Feb 1983
4507990 Lack Apr 1985
4720000 Snyder Jan 1988
4987803 Chern Jan 1991
5054584 Hoffman Oct 1991
5301574 Knopp et al. Apr 1994
5535646 Allen et al. Jul 1996
5537899 Diedrich Jul 1996
Non-Patent Literature Citations (3)
Entry
Three (3) Photographs of a Prior Art Pneumatic Ratchet Wrench manufactured by Snap-On Incorporated.
Operator Instructions for the Prior Art Pneumatic Ratchet Wrench manufactured by Snap-On Incorporated, Applicant'reference AM.
One (1) photograph of a prior art Sears Craftsman hand ratchet wrench.