US2938534A

US2938534A - Actuator for portable tools

Info

Publication number: US2938534A
Authority: US
Inventors: John R Bos
Original assignee: Gardner Denver Inc
Current assignee: Gardner Denver Inc
Priority date: 1956-06-27
Filing date: 1956-06-27
Publication date: 1960-05-31
Anticipated expiration: 1977-05-31

Description

May 31, 1960 .J. R. 505

ACTUATOR FOR PORTABLE TOOLS Filed June 27, 1956 INVENTOR. JOHN E. 505

nited States Patent O ACTUATOR FOR PORTABLE TOOLS John R. Bos, Grand Haven, Mich, assignor to Gardner- Denver Company, Quincy, 11]., a corporation of Delaware Filed June 27, 1956, Ser. No. 594,145

6 Claims. (Cl. 137-343) Wee ting ofi the flow of air to the motor of the tool. Pivotally connected to the head 5 is a control lever 12 which is so arranged that movement of the lever toward the housing moves the valve stem 7 inwardly against the pressure of the air and spring 9 to open the throttle valve 6. Air is then admitted to the motor of the tool,. not shown, through a passage 13.

Tools of the type illustrated are often provided with a clutch of the type shown in the Patent to Shaff No. 2,657,721, issued November 3, 1953. With this type of clutch, actuation of the control lever admits air to start the motor but the work engaging member, such as a screw driving bit, remains disengaged from the driving spindle of the motor until the bit is placed against the work piece and pressure is exerted by the operator to I engage the clutch.

it down against the tension of the balancer to the work 1 piece performing the necessary operation such as driving a screw, setting a nut or drilling a hole. When the operation is completed, the operator releases the tool letting it return to its original position above the work station.

In the operation of such tools, the operator must grasp the tool to pull it down to the work area and further must grasp the tool in such a way that he may also operate the control lever of the tool. In practice, the operator must many times re-grasp or reposition the tool in his hand to properly operate the control lever.

It is an object of this invention to eliminate the need for re-grasping or re-positioning of the tool. by the operator. T

It is a further object of this invention to automatically actuate the control level of a tool when it is pulled down to the work area from its suspended position.

Other objects and features of this invention will become apparent from the following specification and drawings in which:

- In the tool illustrated, a control lever actuator 14 is provided. The actuator is a U-shaped member formed of suitable gauge wire, each of its end portions being wrapped around the turned-in ends 4A of the bail 4' to provide a pivotal connection to the bail 4. The extreme ends 15 of the actuator are turned outwardly to engage the bail 4 to limit the pivotal motion of the actuator with respect to the bail, (Fig. 3). The outwardly turned ends may be bent to various positions to control the pivotal motion between the two

U-shaped members

4 and 14.

A tool provided with a lever actuator, as described herein, and suspended from a spring type balancer is par ticularly adapted to be used by an operator with the tool axis in a vertical position. The valve stem 7, which is biased to extend out of the tool head 5, maintains the lever 12 in a normal position at an angle with respect to the tool axis. The actuator 14 bears against the lever 12 and is also maintained in a normal position at an angle with respect to the tool axis. Similarly, the bail 4 is maintained at an angle with respect to the tool axis Fig. 1 is a view showing a portable hand-held tool suspended from a spring type balancer;

Fig. 2 is an enlarged view of a portion of the tool of Fig. l with the throttle valve of the tool shown in section; and

Fig. 3 is a further enlarged perspective view of a detail of the present invention.

The novelty of the present invention lies in the provision of means which automatically actuates the control level of a tool when the tool is pulled down from a suspended position over a work area.

Referring to the drawings, Fig. 1 shows a portable hand-held pneumatic tool, having an elongated housing including a body 1 and a head 5, suspended from a spring type balancer 2 by a rope 3, or similar member, connected to a U-shaped wire bail 4. The bail 4 has its ends 4A turned inwardly (Fig. 3) and receivable in oppositely positioned sockets in the head 5 of the tool. The balancer 2 includes a stationary shaft 2a, a rotatable drum 2!) carried thereon on which the rope 3 is wound, and a coil spring 20 connected at one end to said shaft and at its other end to said drum. Within the head 5 of the tool is a throttle valve 6 (Fig. 2) comprising a valve stem 7, a bushing or valve seat 8, and a spring 9. In this type of tool air from a source, not shown, is conducted to the tool through suitable conduit means 10 connected to the head of the tool. Air enters the throttle valve chamber through a passage 11. The pressure of the air combines with the pressure exerted by the spring 9 to normally hold the valve 6 against the valve seat 8 shutdue to the manner in which the actuator 14 is mounted on the bail. Due to the coaction of these members, when the tool is suspended its axis lies at an angle with respect to the vertical, as shown in Fig. l.

To operate the tool, the operator needs only to grasp the tool at any point and pull it down to the work area, at the same time aligning the tool in a generally vertical direction. The force exerted by the operator in pulling the tool down against the resisting force of the balancer moves the bail 4 toward the tool axis, this movement being transmitted from the bail through the motion limiting projections of the lever actuator 14 to the control lever' 12 to open the throttle valve 6 thereby admitting air to the motor of the tool.

It will be obvious that the invention accomplishes the automatic starting of a hand-held portable tool when the tool is moved from a suspended position to its work.

It will also be apparent that the invention herein described is applicable to any tools, pneumatically, electrically or otherwise operated, which have an external resilient starting valve or switch controlled by a lever.

It will be obvious to one skilled in the art that the structure described lends itself to additional variations in design which will fall within the scope of the invention claimed. Particularly, the bail 4 and the actuator 14 may be constructed as a single integral member or the control lever 12, the bail 4 and the actuator 14 may be constructed as a single integral member. These members, as combined, act as a single member to perform the described functions.

I claim as my invention:

1. In combination with a hand-held portable tool including: a housing; a control lever pivotally mounted externally of said housing and biased to extend away iromsaid housing; said control lever adapted to actuate said tool when moved toward said housing; a U-shaped bail pivotally connected, at its ends, to said housing; and azspr'ing balancing device having a suspended rope connected to said bail for supporting the weight of said tool: a U-shaped member pivotally connected to said bail-adjacent the ends thereof; said member having projections engaging said bail to limit pivotal movement of said member in one direction with respect to said bail; said member engaging said lever to maintain said bail at an angle with respect to the axis of the tool; said bail adapted V toward said housing; and .a U-shaped bail pivotally connected, at its ends, to said housing; said bail adapted to be-attached to a rope suspended from a spring balancing device for .supporting the weight of said tool: a U-shaped member pivotally connected to said bail'adjacent the ends thereof; said member having projections engaging said bail to limit movement of said member in one direction with respect to said bail; said member engaging said lever tomaintain said bail at an angle with respect to the axis of the tool; said bail adapted to be moved toward the tool axis, when the tool is moved toward its work against the resisting force of a balancing device; and said member transmitting said bail movement to move said control lever toward said housing.

'3. .A hand-held portable tool, for use with a spring balancing device having .a suspended rope, comprising: ahousing; a control lever pivotally mounted externally of said housing and biased to extend away from said housing; saidcontrol lever adapted to actuate said tool when moved toward said housing; a U-shaped bail pivotally connected to said housing for suspending said tool; a U.shaped member connected to said bail; said member being mounted with respect to said bail to limit movement of said member in one direction with respect to said bail; said member engaging said lever to maintain said bail, at an angle with respect to the axis of the tool;

said bail adapted to be moved toward said tool axis, when the tool is moved toward its work against the resisting force of a balancing device; and said member transmitting said bail movement to move said control lever toward said housing.

4. A hand-held portable tool comprising: an elongated housing; a control element, for actuating said tool, resiliently mounted ,on said housing; -a device for resili ently suspending ,said tool above its work; a member pivotally mounted on said housing-for"engagement with said control element and attached to said suspending device; said member normally being maintained at an angle with .respect to the axis of said tool by said control element; and said member adapted to be moved toward said tool axis to actuate saidcontrol element when said tool is moved toward its work against the resisting force of said suspending device.

5. A hand-held portable tool comprising: an elongated housing; .a'control element, for actuating said tool, resiliently mounted on said housing; a member pivotally mounted on said housing for engagement with said control'element; said member having means for attachment to .a devicefor resilientlyw suspending said tool; said membcrnormally being maintained at an angle with respect to the axis ofsaidtool by said control element; and said member adapted to be moved toward said tool axis to actuate said control element when said tool is moved toward its work against the resisting force of a suspending device.

6. A hand-held portable tool for use with a resilient suspendingdevice comprising: an elongated housing; a control element, for actuating said tool, resiliently mounted on said housing; a member pivotally mounted on said housing for engagement with said control element; said member having means for attachment to a resilient suspending device; said member normally being maintained at an angle with respect to the axis of said tool by said control element; and said member adapted to be moved toward said tool axis to actuate said .control element when said tool is moved toward its work against the resisting force ,ofa suspending device. 7

References Citedin the filev of this patent UNITED STATES PATENTS 2,569,244 Larson Sept. 25, 1951