Patent Application
20200189075
The presently invention relates generally to ratchet wrenches. More particularly, the present invention relates to ratchet wrenches having a tube spring bias member.
Ratchet wrenches are common hand tools used to apply torque to work pieces. Ratchet wrenches include a pawl mechanism that allows the tool to torque a work piece in a first rotational direction by rotating the tool in that rotational direction, and then return the tool to its original position by rotating the tool in a second rotational direction opposite the first rotational direction. The pawl mechanism engages a drive gear to impart the torque in the first rotational direction, but allows the pawl to slip relative to the drive gear in the second rotational direction. A reversing lever can reverse which of the first and second rotational directions applies torque to the work piece, for example, if the work piece is left hand threaded or if the user is using the tool to remove the work piece from its position.
Two pawl ratchet wrenches require the pawl to disengage the gear in order to ratchet. Typically this requires the gear to rotate an angle equal to about two to three times the tooth pitch of the pawl teeth. Past wrenches attempt to solve this problem by including a bias member that urges the pawl into engagement with the drive gear, but this arrangement requires a spacer for the spring to pivot and sit within.
The present invention broadly comprises a pawl mechanism with a tube spring as the bias member that biases the pawl into engagement with the drive gear. By biasing the pawl into the drive gear, the tube spring limits lost motion in the engaging pawl. Further, by using a tube spring, a spacer is not needed and instead the tube spring can be disposed in a circular bore.
For example, the present invention broadly comprises a tool including a handle, a head extending from the handle, where the head has first and second bores defined therein. A drive gear is disposed within the head and provides torque to work pieces, and first and second pawls engage the drive gear. A reversing lever is provided and is coupled to the first and second pawls and causes either the first or second pawl to engage the drive gear depending on a position of the reversing lever. First and second tube springs are disposed within the first and second bores. The first and second bores respectively include first and second arcs respectively allowing the first and second tube springs to extend toward the first and second pawls. When the first pawl engages the drive gear, the first tube spring biases the first pawl into engagement with the drive gear, and when the second pawl engages the drive gear, the second tube spring biases the second pawl into engagement with the drive gear.
A ratchet mechanism is further provided and includes first and second pawls adapted to engage a drive gear in an engaging rotational direction and slip about the drive gear in a slip rotational direction. The mechanism can include a reversing lever coupled to the first and second pawls and adapted to cause either the first or second pawl to engage the drive gear depending on a position of the reversing lever. First and second tube springs are disposed within first and second bores of a head of a tool. The first and second bores respectively include first and second arcs respectively allowing the first and second tube springs to extend toward the first and second pawls. When the first pawl engages the drive gear, the first tube spring biases the first pawl into engagement with the drive gear, and when the second pawl engages the drive gear, the second tube spring biases the second pawl into engagement with the drive gear.
For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated.
While this invention is susceptible of embodiments in many different forms, there is shown in the drawings, and will herein be described in detail, a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to embodiments illustrated. As used herein, the term “present invention” is not intended to limit the scope of the claimed invention and is instead a term used to discuss exemplary embodiments of the invention for explanatory purposes only.
The present invention broadly comprises a pawl mechanism with a bias member that biases the pawl into engagement with the drive gear. For example, the bias member can be a tube spring disposed within a bore. By biasing the pawl into the drive gear, the bias member limits lost motion in the engaging pawl; and by using a tube spring, a spacer is not needed and instead the tube spring can be disposed in a circular bore.
As shown in
As discussed above, the pawls 120, 122 can incur lost motion when engaging the drive gear 115 unless the engaging pawl 120, 122 is biased into engagement with the drive gear 115. For this reason, at least some of the presently disclosed embodiments implement first 130 and second 132 bias members to bias the engaging pawl 120, 122 into engagement with the drive gear 115. For example, the first bias member 130 can engage the first pawl 120 when the first pawl 120 is the engaging pawl, and the second bias member 132 can engage the second pawl 122 when the second pawl 122 is the engaging pawl.
As shown in
The tool 100 can further include a ball 145 and spring 147, collectively referred to as a ball detent mechanism 150. The ball detent mechanism 150 sits within a hole 155 of the head 105 and is biased in the upward direction, toward the bottom of the reversing lever 125, as shown in
The head 105 can include various chambers and open areas to receive and house the mechanisms of the head 105. For example, the head 105 can include the valley 160, as discussed above, which can receive the ball detent mechanism 150 and also the reversing lever 125, for example the body 138 of the reversing lever 125. The valley 160 can further lead to a shelf 163 where the knob 140 of the reversing lever 125 rotates within so that the body 138 and the knob 140 can be located slightly below the top surface of the head 105. The head 105 can also include a pawl chamber 165 that receives the pawls 120, 122 of the tool 100, and a gear opening 167 that receives the drive gear 115.
As shown in
The bias members 130, 132 can be tube springs that impart bias onto the respective pawl 120, 122. In doing so, the bias members 130, 132 do not require a separate spacer and can instead be disposed within the bores 180, 185. The tool 100 can therefore ratchet with limited lost motion while not requiring a spacer or other additional components.
As used herein, the term “coupled” and its functional equivalents are not intended to necessarily be limited to direct, mechanical coupling of two or more components. Instead, the term “coupled” and its functional equivalents are intended to mean any direct or indirect mechanical, electrical, or chemical connection between two or more objects, features, work pieces, and/or environmental matter. “Coupled” is also intended to mean, in some examples, one object being integral with another object.
The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of the inventors' contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
