Rotary impact wrench mechanism

Claim 2

A rotary impact wrench mechanism comprising: a rotary driving member; a rotary driven member; an anvil element having an anvil impact surface and connected to said rotary driven member; a hammer element mounted to rotate adjacent said anvil and having a hammer impact surface adapted to engage said anvil impact surface periodically as said hammer element rotates, said hammer element being connected to said rotary driving member; said members being connected to their respective elements by a means which prevents relative rotary movement therebetween; cam means operative to relatively position said anvil and hammer impact surfaces to cause said surfaces to periodically engage; and one of said anvil and hammer elements being connected to its member by a yieldable joint allowing said one element to move transversely relative to the other element to cause the two impact surfaces to automatically disengage each other following each impact.

Claim 3

The mechanism of claim 1 wherein: said hammer element includes an axial bore surrounding said anvil element; said hammer impact surface being a radially extending shoulder projecting inwardly from the wall of said bore; and said anvil impact surface being a radially extending shoulder projecting outwardly from said anvil element.

Claim 4

The mechanism of claim 2 including: means resiliently holding said hammer and anvil elements in substantially parallel planes while allowing them to move transversely relative to each other.

Claim 5

The mechanism of claim 3 wherein: said means resiliently holding said hammer and anvil elements in substantially parallel planes is a hollow case substantially surrounding said hammer and anvil and containing a spring disposed between one of said elements and said case and positioned substantially coaxially with said elements.

Claim 6

A rotary impact wrench comprising: motor driving a rotary driving member; a rotary spindle member adapted to drive fasteners; an anvil element having an anvil impact surface and connected to said rotary spindle member; a hammer element connected to said rotary driving member and mounted to rotate adjacent said anvil, said hammer element having a hammer impact surface adapted to engage said anvil impact surface periodically as said hammer rotates; said members being connected to their respective elements by a means which prevents relative rotary movement therebetween; cam means operative to relatively position said anvil and hammer impact surfaces to cause said surfaces to periodically engage to deliver an impact to said anVil; and one of said anvil and hammer elements being connected to its member by a yieldable joint allowing said one element to move transversely relative to the other element to cause the two impact surfaces to automatically cam each other apart under the application of torque from said motor following each impact.

Claim 7

A rotary impact wrench comprising: motor driving a rotary driving member; a rotary spindle member adapted to drive fasteners; an anvil element having an anvil impact surface and connected to said rotary spindle member; a hammer element connected to said rotary driving member and mounted to rotate adjacent said anvil, said hammer element having a hammer impact surface adapted to engage said anvil impact surface periodically as said hammer rotates; said members being connected to their respective elements by a means which prevents relative rotary movement therebetween; cam means operative to relatively position said anvil and hammer impact surfaces to cause said surfaces to periodically engage to deliver an impact to said anVil; and one of said anvil and hammer elements being connected to its member by a yieldable joint allowing said one element to move transversely relative to the other element to cause the two impact surfaces to automatically cam each other apart under the application of torque from said motor following each impact.

Claim 8

A rotary impact wrench comprising: a motor; a rotary driving member connected to said motor; a rotary driven member adapted to drive a fastener; an anvil element connected to said rotary driven member and having an anvil impact surface; a hammer element mounted to rotate adjacent said anvil connected to said rotary driving member, said hammer element having a hammer impact surface adapted to engage said anvil impact surface periodically as said hammer element rotates; said members being connected to their respective elements by a means which prevents relative rotary movement therebetween; means holding said anvil and hammer elements together to maintain them in parallel planes while they rotate; cam means operative to relatively position said anvil and hammer impact surface to cause said surfaces to periodically engage; and one of said anvil and hammer elements being connected to its member by a joint allowing said one element to move transversely relative to the other element to cause the two impact surfaces to automatically disengage each other following each impact.

Claim 9

A rotary impact wrench comprising: a motor; a rotary driving member connected to said motor; a rotary driven member adapted to drive a fastener; an anvil element connected to said rotary driven member and having an anvil impact surface; a hammer element mounted to rotate adjacent said anvil connected to said rotary driving member, said hammer element having a hammer impact surface adapted to engage said anvil impact surface periodically as said hammer element rotates; said members being connected to their respective elements by a means which prevents relative rotary movement therebetween; means holding said anvil and hammer elements together to maintain them in parallel planes while they rotate; cam means operative to relatively position said anvil and hammer impact surface to cause said surfaces to periodically engage; and one of said anvil and hammer elements being connected to its member by a joint allowing said one element to move transversely relative to the other element to cause the two impact surfaces to automatically disengage each other following each impact.

Claim 10

A rotary impact wrench mechanism comprising: a hammer element connected to a rotary driving member; an anvil element connected to a rotary driven member; said members being connected to their respective elements by a means which prevents relative rotary movement therebetween; one of said elements having a bore that receives and rotates around the other element; said one element including a pair of radially extending steps or shoulders located within said bore, spaced substantially diametrically from each other and facing in opposite rotary directions; and said other element including a pair of radially extending steps or shoulders spaced substantially diametrically from each other and facing in opposite rotary directions.

Claim 11

A rotary impact wrench mechanism comprising: a hammer element connected to a rotary driving member; an anvil element connected to a rotary driven member; said members being connected to their respective elements by a means which prevents relative rotary movement therebetween; one of said elements having a bore that receives and rotates around the other element; said one element including a pair of radially extending steps or shoulders located within said bore, spaced substantially diametrically from each other and facing in opposite rotary directions; and said other element including a pair of radially extending steps or shoulders spaced substantially diametrically from each other and facing in opposite rotary directions.

Claim 12

The mechanism of claim 7 wherein: said pair of shoulders on said one element are interconnected by a cam lobe surface projecting radially inwardly into the bore; and said pair of shoulders on said other element are interconnected by a cam lobe surface projecting radially outward from said other element; said cam lobe surfaces being adapted to interengage to move said elements periodically into impact position as said hammer element rotates relative to said anvil element.

Claim 13

The mechanism of claim 8 wherein: said cam lobe surfaces are arcuate surfaces.

Claim 14

The mechanism of claim 9 wherein: one of said members is connected to its element by a joint allowing that element to move transversely relative to the opposite element.

Claim 15

The mechanism of claim 8 including: means resiliently holding said elements in substantially parallel planes and holding their axes parallel to each other while allowing them to move transversely relative to each other.