US3788403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powered impact tool
Assignee: Individual
•
Filing: 1972-05-15
•
Granted: 1974-01-29
•
Expires: 1992-05-15
Abstract
Abstract A powered impact tool, such as an automatic hammer, chisel, star drill, or the like, is provided which comprises a spring loaded anvil mounted at one end of a housing; a spring loaded plunger, or piston, mounted within the housing; a carriage which slides reciprocally within the housing; a drive for the carriage which imparts the desired reciprocal movement to the carriage; and a pawl which releasably couples the piston to the carriage to permit the carriage to draw the piston back against its spring, and which releases the piston at a selected point of each stroke of the carriage so that the piston spring drives the piston against the anvil which in turn drives the anvil through the end of the housing so that the anvil may provide a high impacting force on the nail or other object being impacted by the tool. An adjustable trigger is also provided by which the displacement of each stroke of the piston, and thus the impact with which it strikes the anvil, can be controlled.
Inventors
- 👤 W Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:59
CPC Classifications
B; B25; B25D; B25D11/00; B25D11/06; B25D11/005; Y; Y10; Y10T; Y10T74/00; Y10T74/18; Y10T74/18056; Y10T74/18248; Y10T74/18256
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
235 words
An automatic power impact tool comprising: an elongated housing; handle means for holding the housing stationary while the tool is in operation; an anvil slidably mounted at one end of the stationary housing and projecting therefrom to form a head for the tool; a first resilient means coupled to said stationary housing and to said anvil for biasing said anvil inwardly with respect to said housing; a piston slidably mounted in said housing independently of said anvil in axial alignment with said anvil; a second resilient means coupled to said housing and to said piston for driving said piston along said housing towards said anvil to cause said piston to impact with said anvil and drive said anvil outwardly with respect to said housing and against the biasing action of said first resilient means; a carriage slidably mounted in said housing at the opposite end thereof to said anvil and in spaced axial alignment with respect to said piston; a drive means coupled to said carriage for imparting reciprocal movement to said carriage within said housing coaxially with said piston; pawl means releasably coupling said piston to said carriage to cause said piston to be moved by said carriage against the action of said second resilient means; and cam means mounted in said housing in position to engage said pawl means at a particular point of each sTroke of said carriage to release said piston.
Claim 2
Dependent Claim
235 words
An automatic power impact tool comprising: an elongated housing; handle means for holding the housing stationary while the tool is in operation; an anvil slidably mounted at one end of the stationary housing and projecting therefrom to form a head for the tool; a first resilient means coupled to said stationary housing and to said anvil for biasing said anvil inwardly with respect to said housing; a piston slidably mounted in said housing independently of said anvil in axial alignment with said anvil; a second resilient means coupled to said housing and to said piston for driving said piston along said housing towards said anvil to cause said piston to impact with said anvil and drive said anvil outwardly with respect to said housing and against the biasing action of said first resilient means; a carriage slidably mounted in said housing at the opposite end thereof to said anvil and in spaced axial alignment with respect to said piston; a drive means coupled to said carriage for imparting reciprocal movement to said carriage within said housing coaxially with said piston; pawl means releasably coupling said piston to said carriage to cause said piston to be moved by said carriage against the action of said second resilient means; and cam means mounted in said housing in position to engage said pawl means at a particular point of each sTroke of said carriage to release said piston.
Claim 3
Dependent Claim
25 words
The combination defined in claim 1, in which said drive means comprises an electric motor and transmission gear means coupling said motor to said carriage.
Claim 4
Dependent Claim
21 words
The combination defined in claim 1, in which said first and second resilient means comprise respectively first and second coil springs.
Claim 5
Dependent Claim
209 words
An automatic power impact tool comprising: a housing; an anvil slidably mounted at one end of the housing and projecting therefrom to form a head for the tool; a first resilient means coupled to said housing and to said anvil for biasing said anvil inwardly with respect to said housing; a piston slidably mounted in said housing in axial alignment with said anvil; a second resilient means coupled to said housing and to said piston for driving said piston towards said anvil to cause said piston to impact with said anvil and drive said anvil outwardly with respect to said housing and against the biasing action of said first resilient means; a carriage slidably mounted in said housing; a drive means coupled to said carriage for imparting reciprocal movement to said carriage; pawl means releasably coupling said piston to said carriage to cause said piston to be moved by said carriage against the action of said second resilient means; cam means mounted in said housing in position to engage said pawl means at a particular point of each stroke of said carriage to release said piston; and manually operated control means coupled to said cam means to adjust the position of said point at which said piston is released.
Claim 6
Dependent Claim
209 words
An automatic power impact tool comprising: a housing; an anvil slidably mounted at one end of the housing and projecting therefrom to form a head for the tool; a first resilient means coupled to said housing and to said anvil for biasing said anvil inwardly with respect to said housing; a piston slidably mounted in said housing in axial alignment with said anvil; a second resilient means coupled to said housing and to said piston for driving said piston towards said anvil to cause said piston to impact with said anvil and drive said anvil outwardly with respect to said housing and against the biasing action of said first resilient means; a carriage slidably mounted in said housing; a drive means coupled to said carriage for imparting reciprocal movement to said carriage; pawl means releasably coupling said piston to said carriage to cause said piston to be moved by said carriage against the action of said second resilient means; cam means mounted in said housing in position to engage said pawl means at a particular point of each stroke of said carriage to release said piston; and manually operated control means coupled to said cam means to adjust the position of said point at which said piston is released.
Claim 7
Dependent Claim
33 words
The combination defined in claim 4, and which includes a pistol grip affixed to said housing, and in which said manually operated control means comprises a trigger member mounted in said pistol grip.
Claim 8
Dependent Claim
49 words
The combination defined in claim 2, in which said transmission gear means includes a drive gear and an eccentric drive pin engaging a slot in said carriage for converting rotary motion into reciprocating motion, and a worm gear for imparting speed reduction between the electric motor and the carriage.
Claim 9
Dependent Claim
34 words
The combination defined in claim 6, in which said electric motor includes a drive shaft axially aligned with the axis of said piston, and gear means coupling said drive shaft to said worm gear.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |