Transmission with first and second transmission elements

Abstract

A transmission includes a first component, a second component, and first and second transmission elements. The first component has a drive member and a portion configured to be actuated to inhibit movement of the drive member. The first and second transmission elements are each coupled to the drive member and the second component and configured to cause movement of at least one of the first component and the second component in response to movement of the drive member. At least one of the first and second transmission elements includes a first plurality of transmission sub-elements.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS[0001]This application claims priority to U.S. Provisional Patent Application Ser. No. 61 / 203,475, filed on Dec. 23, 2008, which is hereby incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of Invention[0003]The present invention relates to a transmission, particularly a tension element drive system for a robotic arm.[0004]2. Description of Related Art[0005]Robotic systems are often used in applications that require a high degree of accuracy and / or precision, such as surgical procedures or other complex tasks. Such systems may include various types of robots, such as autonomous, teleoperated, semi-active, passive, and interactive. For example, in joint replacement surgery, a surgeon can use an interactive, haptically guided robotic arm in a passive manner to sculpt bone to receive a joint implant, such as a knee implant. To sculpt bone, the surgeon manually grasps and manipulates the robotic arm to move a...

AI Technical Summary

Benefits of technology

The present invention is a transmission that includes a first component, a second component, and first and second transmission elements. The first component has a drive member and a portion that can be actuated to prevent movement of the drive member. The first and second transmission elements are connected to the drive member and the second component. These elements cause movement of either the first or second component when the drive member moves. One of the transmission elements has multiple sub-elements. The technical effect of this invention is a more efficient and reliable transmission system that allows for smooth movement of components.

Problems solved by technology

One difficulty with conventional tension element drive systems, however, is that they may not be sufficiently fail-safe for use in surgical applications where failure of the drive system could endanger a patient.

For example, failure of one tension element (e.g., a cable or cord) in the drive system could result in unintended movement of the robotic arm that could harm the patient.

Incorporation of joint brakes, however, increases the weight and inertia of the robotic arm, which adversely impacts backdrivability and haptic response.

Another difficulty with conventional tension element drive systems is that the tension elements must be pre-tensioned to eliminate slack that may cause backlash.

The high load also increases friction forces in the drive system components and contributes to surgeon fatigue.

Another difficulty with conventional tension element drive systems is that such drive systems may not be easily manufactured, serviced, and / or upgraded.

Thus, if one portion of the drive system is defective, it may be necessary to dismantle other portions of the drive system that are functioning properly in order to repair the defective portion.

The inability to isolate portions of a conventional tension element drive system increases the time and labor required to service and upgrade the robotic arm, which results in costly repairs and lengthy downtime that reduces a hospital's ability to optimize use of the robotic arm.

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