Vacuum fitting adapter for bench dog holes

1 . A vacuum fitting adapter configured for installation in a bench dog hole of a worktop and configured for providing fluid communication between a vacuum source and the worktop, the vacuum fitting adapter comprising:

a cylindrical adapter body sized to be inserted into the bench dog hole, the cylindrical adapter body having a through hole traversing from a top end to a bottom end thereof;

the bottom end of the adapter body including a vacuum connection port;

a vacuum coupling attached to the vacuum connection port and configured for connection to the vacuum source;

at least one sealing element on the adapter body operative to reduce fluid leakage between the adapter body and the bench dog hole and to create a friction fit therebetween;

a retention mechanism fixed with the cylindrical adapter body and configured to press outwardly against an interior wall of the bench dog hole to enhance retention of the adapter body, wherein the retention mechanism includes a cap configured to expand the at least one sealing element radially outward to contact an interior sidewall of the bench dog hole.

2 . The vacuum fitting adapter of claim 1 wherein the retention mechanism compresses a second sealing element distinct from the at least one sealing element to expand the second sealing element to contact the interior sidewall of the bench dog hole.

3 . The vacuum fitting adapter of claim 2 , wherein the at least one sealing element comprises an elastomeric O-ring.

4 . The vacuum fitting adapter of claim 1 , further comprising an elastomeric vacuum seal positioned on top of the worktop around the bench dog hole to provide a vacuum seal between the worktop and a workpiece being held by the worktop.

5 . The vacuum fitting adapter of claim 4 , wherein the elastomeric vacuum seal comprises at least one of Neoprene or silicon rubber.

6 . A workholding system comprising:

a worktop having a bench dog hole;

a vacuum fitting adapter configured for installation in the bench dog hole, the vacuum fitting adapter comprising a cylindrical adapter body sized to be inserted into the bench dog hole, the cylindrical adapter body having a through hole traversing from a top end to a bottom end thereof, the bottom end including a vacuum connection port, a vacuum coupling attached to the vacuum connection port and configured for connection to a vacuum source, at least one sealing element on the adapter body operative to reduce fluid leakage between the adapter body and the bench dog hole and to create a friction fit therebetween, and a retention mechanism fixed with the cylindrical adapter body and configured to press outwardly against an interior wall of the bench dog hole to enhance retention of the adapter body, wherein the retention mechanism includes a cap configured to expand the at least one sealing element radially outward to contact an interior sidewall of the bench dog hole; and

an elastomeric vacuum seal positioned on a top surface of the worktop around the bench dog hole to provide a vacuum seal between the worktop and a workpiece.

7 . The vacuum fitting adapter of claim 1 , further comprising an in-line filter installed within the through hole of the adapter body and operative to filter particulate matter.

8 . The vacuum fitting adapter of claim 1 , wherein the adapter body comprises at least one groove laterally positioned around an external surface of the adapter body and configured to receive the at least one sealing element.

9 . The vacuum fitting adapter of claim 1 , wherein the cap includes a non-chamfered top edge for bench dog holes having non-chamfered edges.

10 . The vacuum fitting adapter of claim 1 , wherein the cap has a chamfered top edge for bench dog holes having chamfered edges.

11 . The vacuum fitting adapter of claim 1 , further comprising one or more coupling elements that attach below the adapter body to extend the adapter body downwardly for thicker worktops.

12 . The vacuum fitting adapter of claim 1 , wherein the adapter body is configured to be removable by pushing the vacuum fitting adapter up through the bench dog hole.

13 . The vacuum fitting adapter of claim 1 , wherein the adapter body comprises a gripping surface laterally distributed around the adapter body to facilitate insertion and removal from the bench dog hole.

14 . A method of installing a vacuum fitting adapter in a bench dog hole of a worktop, the method comprising:

providing a vacuum fitting adapter comprising a cylindrical adapter body sized to be inserted into the bench dog hole, the cylindrical adapter body having a through hole traversing from a top end to a bottom end thereof, the bottom end including a vacuum connection port, a vacuum coupling attached to the vacuum connection port and configured for connection to a vacuum source, at least one sealing element on the adapter body operative to reduce fluid leakage between the adapter body and the bench dog hole and to create a friction fit therebetween, a retention mechanism fixed with the cylindrical adapter body and configured to press outwardly against an interior wall of the bench dog hole to enhance retention of the adapter body, wherein the retention mechanism includes a cap configured to expand the at least one sealing element radially outward to contact an interior sidewall of the bench dog hole;

placing the sealing element in a groove on the adapter body;

placing a sealing element on a top of the adapter body and screwing in the cap with threads thereof passing through a center of the sealing element, screwing the cap until it makes contact with the sealing element without compressing the sealing element;

screwing the vacuum coupling into threads of the vacuum connection port;

pushing the assembled vacuum fitting adapter into the bench dog hole from a top of the worktop, with the sealing elements causing a friction fit as they are compressed against interior walls of the bench dog hole;

adjusting the cap to compress the sealing element radially outward to contact the interior walls of the bench dog hole and secure the vacuum fitting adapter into the bench dog hole; and

connecting the vacuum source to the vacuum coupling to provide vacuum to the worktop.

15 . The method of claim 14 , wherein pushing the assembled vacuum fitting adapter into the bench dog hole from the top of the worktop further includes:

a top of the cap being positioned flush with the top surface of the worktop or slightly below it, unless the bench dog hole is chamfered in which case a chamfered top edge of the cap limits insertion.