Conventional designs for reversible torque wrenches suffer from design defects that result in various failures and inconveniences to a user. Many typical reversible torque wrenches are designed for two hand manipulation of reversing mechanisms. Conventional designs also result in off-axis locking and auto reverse. Embodiments described herein eliminate off-axis locking and auto reverse and allow single hand manipulation of reversing mechanisms.
Embodiments of a torque transfer device are described. In one embodiment, a torque transfer device includes a handle, a roller cage bias ring, a plurality of rollers and a spindle. The handle includes a scalloped outer race. The roller cage bias ring is located within the scalloped outer race. The roller cage bias ring includes a base ring and a plurality of pillars extending out of the base ring. The rollers are positioned between the pillars. The spindle includes a circular inner race. Other embodiments of a torque transfer device are described.
Other aspects and advantages of embodiments of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrated by way of example of the principles of the invention.
It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single figure, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. Similarly, not every embodiment need accomplish all advantages of the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Throughout the description, similar reference numbers may be used to identify similar elements.
In the following description, specific details of various embodiments are provided. However, some embodiments may be practiced with less than all of these specific details. In other instances, certain methods, procedures, components, structures, and/or functions are described in no more detail than to enable the various embodiments of the invention, for the sake of brevity and clarity.
It will be readily understood that the components of the embodiments as generally described herein and illustrated could be arranged and designed in a wide variety of different configurations. Thus, the following description of various embodiments, and as represented in the figures, is not intended to limit the scope of the present disclosure, but is merely representative of various embodiments.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. All changes which come within the meaning and range of equivalency of the description and claims are to be embraced within their scope.
Reference throughout to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussions of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
Reference to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the present invention. Thus, the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
While many embodiments are described herein, at least some of the described embodiments relate generally to a reversible torque transfer device. This clutch design may be used in many different applications. The example used for the illustrative purposes of this patent is a socket wrench.
The industry standard for indexing wrenches include a “roundhead” or a “pearhead”, where the roundhead has a circular head shape and the pearhead has an elongated head shape. The individual shape is derived from the geometry of the interior gears and reverse mechanism. In general, the roundhead reverse switch requires both hands to engage while the pearhead reverse switch will engage with a single hand.
For the class of wrenches that employ a reversible roller clutch to transfer torque from the wrench to the fastener, existing designs are configured with a smooth outer race, a ramped inner race, and the roundhead shape. Each of these designs utilizes a reverse switch which is located in the center of the wrench head and requires the operator to apply both hands to the handle in order to shift from forward into reverse or vice versa. A functional roundhead design with a reversing mechanism for the inner race has been previously disclosed by Douglass (U.S. Pat. No. 8,904,907). The current specification discloses embodiments of a reversible roller clutch configured with a smooth inner race, a ramped or scalloped outer race, and a pearhead shape. In addition, embodiments include a reversing mechanism which enables the operator to shift directions using only a single hand.
Several inventors including Mitchell (U.S. Pat. No. 6,055,888) and Albertson (U.S. Pat. No. 6,276,239) have previously disclosed reversible roller clutch designs which fall under the roundhead category. Unfortunately each of these designs suffers from a variety of engineering flaws including off-axis locking, brinelling, and auto reverse. These inherent defects have rendered them impractical in the real world and have led to costly recalls from the marketplace. In addition, the designs requires the operator to remove the device from the working surface and apply both hands to engage the reverse switch. Both of these actions are time consuming and defeat the purpose of the original ratcheting wrench.
Some embodiments of the present disclosure illustrate a ramped or scalloped outer race in combination with an efficient cage assembly including a roller cage bias ring and rollers to eliminate or greatly reduce off-axis locking and auto reverse. Locating the ramps or scallops on the outer race eliminates or greatly reduces the possibility of off-axis locking (OAL) and auto reverse. Off-axis locking occurs in conventional designs when the operator applies a force to the handle while the handle is not parallel to the working surface. Off-axis stress allows the spindle to fall out of alignment with the head and to locate itself in an off-axis position. The angle of the spindle releases the contact on one or two rollers which will automatically seek the path of least resistance and slide onto the opposite side of the ramp. At that point the spindle will lock in both directions with some of the rollers holding the forward position and the balance holding the reverse position. The tool is now in failure mode and inoperable. Off-axis locking occurs with conventional inner race designs. The reason for such a failure is the relationship between the rollers and the spindle. The inner race requires the spindle and the rollers to rotate together within the housing. Each roller is mated to one ramp and both of them turn simultaneously. The spindle and rollers float within the head until the operator applies a force to the handle. This force compresses the rollers between the ramps and the housing. If the compressive force is uneven as is the case with OAL then a number of the rollers will roll out of position and lock the spindle in either direction. Embodiments disclosed herein eliminate or greatly reduce off-axis locking. Embodiments disclosed herein (with an outer race configuration) function in the opposite manner. The ramps are attached to the head or handle and do not rotate with the spindle. In some embodiments, each roller is mated with one ramp of a scallop and is also stationary as only the spindle rotates. This lack of freedom confines the rollers and eliminates their ability to move out of position. Therefore a solution to OAL is found in embodiments disclosed herein with an outer race configuration.
Some embodiments include a roller cage bias ring. One of the purposes of the roller cage bias ring is to simultaneously locate each of the rollers in their correct position between the spindle and the scalloped outer race. Once this position has been achieved it becomes possible to lock the spindle in place and apply a tremendous amount of torque to the socket and fastener. More importantly, the cage assembly will eliminate brinelling and roller slip.
Some embodiments include a cage assembly comprising of a base ring and a top ring. Each ring has pillars (spacing elements or fingers) attached that are designed to position the individual rollers within their assigned scallop. In some embodiments, the base ring is rotated by a reverse lever and simultaneously urges each roller into position. In some embodiments, the reverse lever is located at the intersection between a handle and a wrench head. In some embodiments, the wrench head is integral to the handle and do not move relative to each other. In some embodiments, elongating the head to accept a reverse lever or switch gives the tool the “pearhead” shape.
In some embodiments, the cage assembly is designed to apply a consistent urging effect to the rollers. This urging effect enables the rollers to move out of a neutral position relative to the scalloped outer race and to start climbing the scalloped ramps. Each of these rollers must maintain an identical location on their individual ramp and remain parallel to the drive spindle. This simultaneous engagement is provided by disclosed embodiments.
In some embodiments, the reverse lever which is operated with a single hand and rotates a cage assembly or roller cage bias ring placed between a scalloped outer race and a spindle with a smooth inner race. Embodiments disclosed herein are faster, ergonomic, and more efficient than the two handed switch designs currently available with roller clutches. This benefit enables an operator to rapidly change from forward to reverse without the delayed effect created by removing both hands from the work area.
In addition, some embodiments designed to eliminate auto reversal of a spindle. In conventional designs (inner race configurations), sudden reversal of the spindle may occur at high torque levels. Such design defects are a result of the geometry of conventional race ramps, the mobility of the rollers, and a lack of sufficient contact surface. The spindle utilizes a hertzian contact stress to stabilize the rollers. This contact stress may be overpowered with a sufficient torque load. At that point the rollers move to the opposite side of the ramp with a sudden loss of torque. This is a dangerous reaction in the event an operator impacts his hands on a solid surface such as an engine or fan blade. Sudden reversal of this type is eliminated with the outer race design and embodiments disclosed herein. The individual rollers are locked into place with the scallops and do not rotate with the spindle. In addition, the scallops provide the correct amount of contact surface area needed to maintain the load. The combination of the race geometry and the confined rollers is a solution to the sudden reverse of conventional designs.
It is important that sufficient contact surface area exists between the rollers, the spindle and the housing as illustrated in U.S. Pat. No. 6,044,944 by Adams and hereby incorporated into this specification. The present disclosure illustrates the concave scalloped shape of the outer race mated with the convex face of the rollers. This is a geometry for maintaining a minimum contact surface area required to achieve maximum torque and to eliminate brinelling.
Embodiments disclosed herein are improvements over existing roller clutch designs and enables devices to be stronger, safer and easier to operate.
The illustrated embodiment includes a reverse lever 102, a spindle 104 including a circular inner race (internal, not shown), and a handle 106 including a pearhead shaped head portion. In the illustrated embodiment, the reverse lever 102 includes two positions. A first position of the reverse lever 102 allows the spindle 104 to rotate relative to the handle 106 in one of a clockwise or a counter-clockwise direction and restricts rotation of the spindle 104 relative to the handle 106 in the opposite. A second position of the reverse lever 102 will reverse the allowed rotational direction and restricted rotational direction of the spindle 104 relative to the handle. In the illustrated embodiment, the spindle 104 is configured to attach to various attachments or sockets and drive rotation of the attachments or sockets.
Embodiments of a single hand reverse lever 102 are safer to engage than a two handed design. This is helpful for an operator working at the top of a ladder or an elevated platform as it allows for one hand to work the wrench and the other hand to hold on for balance.
The illustrated embodiment depicts a quick release plunger 108 that in some embodiments may be depressed and will release the socket or attachment attached to the spindle.
In the illustrated embodiment, the handle 106 includes a head portion including the scalloped outer race 500. In some embodiments, the head and handle are integral to each other. In some embodiments, the handle 106 may include a detachable head housing. In some embodiments, the scalloped outer race 500 does not move relative to the handle 106. If the scalloped outer race 500 is a separate piece from the head housing and snaps into place within the housing, then the central axis of the scalloped outer race 500 aligns with the axis of the head housing so as to not move relative to the head housing. In the illustrated embodiment, the handle and the scalloped outer race are one integral piece.
In the illustrated embodiment, the backplate 110 inserts into the rear of the handle 106 and the reverse switch 102 is secured by the shoulder screw 112. The rollers 400 are positioned between the pillars of the roller cage bias ring 300 to form a cage assembly. The cage assembly is located within the scalloped outer race 500. The spindle 104 is located within the cage assembly. In some embodiments, the rollers 400 interface with the scalloped outer race 500 and the circular inner race 602 of the spindle 104. The rollers 400 are indexed by the roller cage bias ring 300 (shown and described more fully in
In some embodiments, the reverse lever 102 is configured to interface with the roller cage bias ring 300. In some embodiments, the reverse lever 102 includes a knob 118 (see
The illustrated embodiment of the roller 400 is primarily cylindrical in shape.
The rollers 400 are not restricted to a circular cylinder as depicted in
The illustrated embodiment depicts twenty four scallops 502 on the outer race. Each individual scallop 502 includes two opposing sloped concave ramp surfaces, a first sloped ramp surface 504 and a second sloped ramp surface 506. The rollers 400 are indexed by the roller cage bias ring 300 to one of the sloped concave ramp surfaces. Also depicted is the mating cavity 508 for the reverse lever 102 and shoulder screw 112. And the landing surface 512 for the front cap 114.
In the above description, specific details of various embodiments are provided. However, some embodiments may be practiced with less than all of these specific details. In other instances, certain methods, procedures, components, structures, and/or functions are described in no more detail than to enable the various embodiments of the invention, for the sake of brevity and clarity.
Although specific embodiments of the invention have been described and illustrated, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. The scope of the invention is to be defined by the claims appended hereto and their equivalents.
Although various embodiments have been shown and described, the present disclosure is not so limited and will be understood to include all such modifications and variations are would be apparent to one skilled in the art.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/100,358 filed on Jan. 6, 2015, and entitled “Reversible Roller Wrench with a Scalloped Outer Race,” the contents of which are hereby incorporated by reference herein.
Number | Date | Country | |
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62100358 | Jan 2015 | US |