Patent Application
20090120244
The present invention relates to tightening of hex-shaped male and female threaded nuts to connect a pipe, and more particularly provides a power wrench for rotating one of the nuts and a nut holding plate for holding the other nut during the rotation of the one nut.
It is known to connect together a first pipe and a second pipe via threaded male and female pipe connecting nuts. Both of the nuts can be rotated, or one nut can be rotated while holding the other nut stationary. It would be desirable to provide a new and improved wrench for rotating the one nut while the wrench also holds the other nut stationary.
A wrench for tightening threaded male and female pipe nuts includes a wrench gear rotatable within a housing and having gear teeth on the periphery thereof. A nut slot is provided in the periphery so that the wrench gear can be engaged upon one of the nuts. A pair of pinion drive gears is rotatably mounted on the housing and engaging with the gear teeth of the wrench gear at spaced apart locations on the periphery so that at least one of the pinion drive gears is engaged with the wrench gear at all times during rotation of the wrench gear to tighten the one nut. A nut holding plate has a nut slot so that the nut holding plate can be engaged upon the other of the nuts. The nut holding plate is mounted on the housing by a pin and slot arrangement so that the nut holding plate can shift relative to the housing and the wrench gear to enable the nut holding plate to be engaged upon the other nut irrespective of the relative rotational position of the one nut and the other nut when the wrench gear and the nut holding plate are installed onto the nuts.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of certain exemplary embodiments is exemplary in nature and is not intended to limit the invention, its application, or uses.
Referring to
Pipe 18 has a threaded female nut 20 that is rotatable on the end of the pipe 18. The pipe 18 has a flange or a sealing ring that engages with the female nut 20 so that the nut 20 is retained on the end of the pipe 18 but permitted to rotate. The outside of the nut 20 is hex-shaped.
A power wrench,
Pinion drive gears 58 and 60 are seated respectively on the pivot pins 52 and 54. A wrench gear 66 has peripheral gear teeth 68 that slide on the curved wall portions 46 and 48 of the housing base wall 38 and also mesh with teeth 72 and 74 of the pinion drive gears 58 and 60 so that the wrench gear 66 is rotatably captured by the pinion drive gears 58 and 60 and the curved wall portions 46 and 48. The wrench gear 66 has an open end wrench slot 78 that is shaped and dimensioned to fit onto the hex shape of the threaded male nut 12. Chamfers 80 and 82 are provided on the wrench gear 66 at the entry of the wrench slot 78. As seen in
A drive gear 86 has peripheral teeth 88 that mesh with the teeth 72 and 74 of the pinion drive gears 58 and 60. A drive shaft 90 is provided for driving the drive gear 86 and includes a body 92 located outside the housing 28 and a shaft 94 that extends through a hole 98 in the base wall 38 and into a bore 100 in the drive gear 86. The shaft 94 has a flat 104 that engages with a mating flat 106 of the bore 100 so that the drive shaft 90 is keyed to the drive gear 86. The drive shaft 90 has a square socket 110 that is coaxial with the shaft 94. A conventional power driver, either pneumatic or electrical, generally indicated at 114,
Energizing the power driver 114 will rotate the drive shaft 90, which rotates drive gear 86, which rotates the pinion gears 58, which rotate the wrench gear 78 to tighten the male nut 12.
A nut holding plate 120 is provided for holding the nut 20 while the nut 12 is rotated. The nut holding plate 120 has a nut holding slot 122 and lays along side the housing cover 34. Chamfers 21 and 123 are provided on the nut holding plate 120 at the entry of the nut holding slot 122. The nut holding plate 120 is connected to the housing cover 34 by a slot 124 of the nut holding plate 120 that is seated on a pin 126 projecting from the housing cover 34. A spring 130 is provided to urge the nut holding plate 120 to a centered position in which the slot 124 of the nut holding plate 120 is aligned with the wrench slot 78 of the wrench gear 66. The spring 130 has one end 134 that is seated in a hole 136 of the nut holding plate 120, a central portion that wraps around the pin 126, and an end 140 that is anchored on a spring anchor pin 142 mounted on the housing cover 34. As seen in
Thus, in operation, as seen in
The foregoing description of the invention is merely exemplary in nature and, thus, variations thereof are intended to be within the scope of the invention. It will be understood that the wrench 24 can be used in various types of nut-to-nut pipe connections. For example, both the nuts 12 and 20 can be rotatable on the pipes as described above, and the nut holding plate 120 will hold the nut 20 against rotation. Or the nut 20 can be mounted on the pipe 18 in a manner that the nut 20 is fixed to the pipe 18 and does not rotate. Accordingly, if the pipe 18 is of thin wall material, the nut holding plate 120 will hold the nut 20 so that the torque applied by the wrench gear 66 will not twist the thin wall material of the pipe 18. Furthermore, although the drawing herein shows a rotating nut 12 that is a male nut, the nut to be rotated by the wrench gear 68 can be a female nut.
