Safety guard system for band saws and similar equipment

• US 5,377,571 A
• Filed: 10/19/1993
• Issued: 01/03/1995
• Est. Priority Date: 10/19/1993
• Status: Expired due to Fees

• Current Assignee: Harold Josephs
• Original Assignee: Harold Josephs
• Inventors: Josephs, Harold
• Primary Examiner(s): Seidel, Richard K.
• Assistant Examiner(s): WOODS, RAYMOND
• Application Number:
  US08/138,799
• Time in Patent Office: 441 Days
• Field of Search: 83/63, 83/372, 83/440.2, 83/443, 83/446, 83/447, 83/450, 83/478, 83/544, 83/814, 83/820, 83/DIG. 1, 83/67, 83/860, 83/399
• US Class Current: 83/399
• CPC Class Codes: B27G 19/06 for band or strap saws
• CPC Class Codes: F16P 1/00 Safety devices independent of the control and operation of any machine protective devices for the eyes or ears, worn on the body or carried in the hand, A61F9/00, A61F11/00
• CPC Class Codes: Y10S 83/01 Safety devices
• CPC Class Codes: Y10T 83/626 Operation of member controlled by means responsive to position of element remote from member [e.g., interlock]
• CPC Class Codes: Y10T 83/7226 With means to guard the tension
• CPC Class Codes: Y10T 83/732 With guard
• CPC Class Codes: Y10T 83/743 Opposed to work-supporting surface
• CPC Class Codes: Y10T 83/872 With guard means

Abstract

A safety guard system for a band saw that comprises a flexible member and a sensor for deactivating the band saw when the flexible member is not deployed correctly. The flexible member has a resting position and a sawing position. In both positions, the flexible member provides a protective barrier between the band saw user and the band saw blade. The flexible member automatically adjusts by flexing to accommodate different sized work pieces.

Claims

1. A guard for a power saw used to cut a workpiece, the power saw having a blade which is driven by a motor having a power circuit, the blade being enclosed by a housing covering all but a cutting area portion of the blade, a workpiece support platform disposed at one end of the cutting area portion, the guard comprising:

a flexible member having a first end, a middle portion, and a second end, each of said ends being secured to the housing, said flexible member having an at-rest position in which the middle portion of the flexible member extends across the cutting area portion forming a partial-loop, and contacts the workpiece support platform wherein the middle portion of the flexible member normally covers the cutting area portion and a sawing position in which the workpiece is placed on the workpiece support platform with the flexible member being deformed from the at-rest position of the flexible member, and extending from the housing across a first segment of the cutting area portion between the workpiece placed on the workpiece support platform and the housing wherein the workpiece and the flexible member cooperate to cover the cutting area portion as the workpiece is cut; and

a switch in the power circuit, said switch being closed by the flexible member containing the workpiece support platform and by the flexible member contacting the workpiece on the workpiece support platform.

2. The guard in accordance with claim 1 wherein the flexible member is formed of a resilient material having spring-like characteristics so that when the flexible member undergoes deformation due to the placement of the workpiece on the workpiece support platform, the flexible member provides a reaction force on the workpiece support platform and on the workpiece.

3. A guard for a band saw used to cut a workpiece, the band saw having a continuous loop blade which is driven by a motor having a power circuit, the blade being enclosed by a housing covering all but a cutting area portion of the blade, a workpiece support platform disposed at one end of the cutting area portion, the guard comprising:

a flexible member secured to the housing, said flexible member having an at-rest position in which the flexible member extends from the housing across the cutting area portion and contacts the workpiece support platform wherein the flexible member normally covers the cutting area portion and a sawing position in which the workpiece is placed on the workpiece support platform with the flexible member being deformed from the at-rest position of the flexible member, and extending from the housing across a first segment of the cutting area portion between the workpiece placed on the workpiece support platform and the housing wherein the workpiece and the flexible member cooperate to cover the cutting area portion as the work piece is cut, and wherein the flexible member provides a reaction force on the workpiece support platform and the workpiece; and

a switch in the power circuit, said switch being closed by the reaction force on the workpiece support platform and the workpiece.

4. The guard in accordance with claim 3 wherein the reaction force closes the switch and the power circuit through the use of a compression spring.

5. The guard in accordance with claim 3 wherein the reaction force closes the switch and the power circuit through the use of a spring.

6. The guard in accordance with claim 3 wherein the flexible member is a metal band.

7. The guard in accordance with claim 3 wherein the flexible member forms a partial loop, with spring-like characteristics.

8. The guard in accordance with claim 3 wherein the flexible member is formed of a resilient material having spring-like characteristics so that when the flexible member undergoes deformation due to the placement of the workpiece on the workpiece support platform, the flexible member provides a biasing force on the workpiece to help maintain the workpiece against the workpiece support platform.

9. The guard in accordance with claim 3 further comprising a fixture attached to the housing which interconnects the flexible member with the housing.

10. The guard in accordance with claim 3 wherein the flexible member has a forked end having two prongs and the blade extends between the two prongs.

11. A safety system for protecting a user of a saw having a saw blade and a workpiece support platform, the safety system comprising:

a flexible member attached to the saw, the flexible member having an opening through which the saw blade extends, the flexible member having a portion forming a protective barrier between the user of the saw and the saw blade, the flexible member being deformable to simultaneously accommodate a workpiece on the workpiece support platform and maintain the protective barrier between the user and the blade; and

a sensing device operatively coupled to the flexible member such that the sensing device enables operation of the saw when the flexible member is attached to the saw and in contact with the workpiece support platform, and when the flexible member is attached to the saw and in contact with the workpiece; and

the sensing device operatively coupled to the flexible member such that the sensing device generates an output signal when the flexible member becomes detached from the saw; and

means for receiving the output signal and disabling the operation of the saw in response to the output signal.

12. The safety system in accordance with claim 11 further comprising a compression spring, the sensing device detecting whether the flexible member is attached to the saw by sensing compression of the spring.

13. The safety system in accordance with claim 11 wherein said receiving means causes the saw to be inoperable when the sensing device malfunctions.

14. A safety system for protecting a user of a saw having a saw blade and a workpiece support platform, the safety system comprising:

a flexible member attached to the saw, the flexible member having an opening through which the saw blade extends, the flexible member having a portion forming a protective barrier between the user of the saw and the saw blade, the flexible member being deformable to simultaneously accommodate a workpiece on the workpiece support platform and maintain the protective barrier between the user and the blade; and

a sensing device operatively coupled to the flexible member, the sensing device communicating with a power circuit for the saw and said power circuit containing a switch having an opened and a closed position wherein the saw is operable when the switch is in the closed position and inoperable when the switch is in the opened position, the sensing device causing the switch to be closed when the flexible member is attached to the saw and in contact with the workpiece support platform, and when the flexible member is attached to the saw and in contact with the workpiece; and

the sensing device causing the switch to be opened when the flexible member becomes detached from the saw.

15. The safety system in accordance with claim 14 wherein malfunctioning of the sensing device causes the switch to be opened.