← Back to Patent Explorer
US3793776A Expired / Lapsed US ⏱️ 0.0 years remaining

Double insulated portable sander

Assignee: Black and Decker Corp
•
Filing: 1972-07-21
•
Granted: 1974-02-26
•
Expires: 1992-07-21
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A portable sander tool of the orbital type wherein the housing is formed of insulating material, the lower end of the motor shaft being connected to a wear inhibiting sleeve drivably connected with the conventional counterbalance, together with a base plate of insulating material which is provided with a central opening for receiving a bearing having its outer race pressed into a bore in the base plate and having its inner race pressed on to a hub of the counterbalance, the central opening in the plate being sealed by a cap of insulating material thus sealing the lubricant in the bearing opening and preventing access to the bearing and shaft from the bottom of the tool to achieve double insulation, the wear inhibiting sleeve, counterbalance, base plate and bearing being permanently assembled and constituting a self-contained unit or sub-assembly adapted to be removably bolted to the housing for replacement by a new unit in the event this becomes necessary in servicing the tool.

Inventors

  • 👤 R Hurn
  • 👤 P Sadow
  • 👤 G Baum

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 15:27
CPC Classifications
B; B24; B24B; B24B23/00; B24B23/04

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 167 words
In a portable electric sanding tool of the type having a housing formed of insulating material, a rotatable shaft journalled therein and having a free end adapted to be connected to a base plate for oscillating the latter, the base plate being resiliently mounted to the housing, the invention which comprises means for drivably connecting said free end and base plate including a counterbalance secured to said free end for rotation therewith, a hub formed on said counterbalance, a hub formed on said base plate, a bearing structure interconnecting said hubs, said structure having an outer race pressed in an opening in the second-named hub and having an inner race pressed on the first named hub, said base plate being formed of insulating material, said opening in said second-named hub extending through said base plate for facilitating assembly of the bearing races on both of said hubs, and defining a lubricant cavity, and a cap of insulating material closing said opening and sealed to said base plate.
Claim 2
Dependent Claim 167 words
In a portable electric sanding tool of the type having a housing formed of insulating material, a rotatable shaft journalled therein and having a free end adapted to be connected to a base plate for oscillating the latter, the base plate being resiliently mounted to the housing, the invention which comprises means for drivably connecting said free end and base plate including a counterbalance secured to said free end for rotation therewith, a hub formed on said counterbalance, a hub formed on said base plate, a bearing structure interconnecting said hubs, said structure having an outer race pressed in an opening in the second-named hub and having an inner race pressed on the first named hub, said base plate being formed of insulating material, said opening in said second-named hub extending through said base plate for facilitating assembly of the bearing races on both of said hubs, and defining a lubricant cavity, and a cap of insulating material closing said opening and sealed to said base plate.
Claim 3
Dependent Claim 150 words
In a portable electric sanding tool of the type having a housing formed of insulating material, a rotatable shaft journalled therein and having a free end adapted to be connected to a base plate for oscillating the latter, resilient means interconnecting the base plate to the housing, the invention which comprises means for drivably connecting said free end of said shaft and said base plate including a wear inhibiting coupling sleeve provided with a non-circular bore slidably and non-rotatably receiving said shaft free end, said sleeve having a non-circular outer surface, a counterbalance non-rotatably connected to said outer surface for conjoint rotation with said shaft free end and said sleeve, a hub formed on said counterbalance, a hub formed on said base plate, and a bearing interconnecting said hubs, said bearing having an outer race pressed in the second-named hub and an inner race pressed on the first named hub.
Claim 4
Dependent Claim 150 words
In a portable electric sanding tool of the type having a housing formed of insulating material, a rotatable shaft journalled therein and having a free end adapted to be connected to a base plate for oscillating the latter, resilient means interconnecting the base plate to the housing, the invention which comprises means for drivably connecting said free end of said shaft and said base plate including a wear inhibiting coupling sleeve provided with a non-circular bore slidably and non-rotatably receiving said shaft free end, said sleeve having a non-circular outer surface, a counterbalance non-rotatably connected to said outer surface for conjoint rotation with said shaft free end and said sleeve, a hub formed on said counterbalance, a hub formed on said base plate, and a bearing interconnecting said hubs, said bearing having an outer race pressed in the second-named hub and an inner race pressed on the first named hub.
Claim 5
Dependent Claim 81 words
A self-contained sub-assembly unit for a portable electric sanding tool of the type having an insulating housing and a rotatable shaft journalled therein, said unit comprising a base plate of insulating material, a counterbalance, a bearing structure interposed between the base plate and counterbalance, and a wear inhibiting coupling sleeve drivably connected with the counterbalance and provided with a fluted bore, said unit being adapted to be resiliently and removably supported by said housing with said shaft receivable in said bore.
Claim 6
Dependent Claim 81 words
A self-contained sub-assembly unit for a portable electric sanding tool of the type having an insulating housing and a rotatable shaft journalled therein, said unit comprising a base plate of insulating material, a counterbalance, a bearing structure interposed between the base plate and counterbalance, and a wear inhibiting coupling sleeve drivably connected with the counterbalance and provided with a fluted bore, said unit being adapted to be resiliently and removably supported by said housing with said shaft receivable in said bore.
Claim 7
Dependent Claim 20 words
A portable tool as set forth in claim 2 wherein said sleeve bore and said shaft free end are fluted.

References Cited (Backward Citations)

US3345784A Cited
US3520090A Cited
US3555743A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-02-25 1977-08-27 1978-02-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-02-25 1981-08-27 1982-02-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-02-25 1985-08-27 1986-02-26 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag