US3275088A

US3275088A - Reversing means for percussion hammers

Info

Publication number: US3275088A
Application number: US351977A
Authority: US
Inventors: Schrottle Wilhelm
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-03-15
Filing date: 1964-03-16
Publication date: 1966-09-27
Anticipated expiration: 1983-09-27
Also published as: GB1049938A

Description

Sept. 27, 1966 w. scHRTTLE REVERSING MEANS FOR PERCUSSION HAMMERS Filed March 16, 1964 United States Patent O 2 claims. (ci. 173-110) The present invention relates to percussion tools and is particularly concerned with a percussion hammer or drill provided with a tool reversing or turning arrangement; Hammers of this type `are employed for ground breaking operations, chisel, caulking` or cutting work, in underground work as well as in building construction work.

The percussion or beating system of hammers of this type comprises essentially a percussion piston guided for axial movement and iirmly connected for force transmission with the driving elements and which acts on the insert end or shank of the tool.

A hammer of this type can also be used as a boring or drilling hammer for boring in natural rock, artiiical rock, concrete or masonry work, when it is equipped with a boring chisel.

However, when a percussion hammer is inserted as the boring tool, it is necessary to continually turn the tool manually, with the result that the turning speed remains relatively low in relation to the high number of blows of a percussion hammer. Without reversing or turning, the chisel encounters the same notch or score for each blow so that no boring eiect is obtained. The manual turning becomes particularly diliicult when drilling is effected with a beating or blow hammer in a horizontal or overhead direction.

A boring or drilling hammer is also known which has a turning means where the turning takes place evenly during the entire operating time. However, this turning means has the shortcoming that the turning movement would have to take place at the time the tool is applied, i.e., when it is being seated in its notch. Here the overload is disconnected as a result of the blocked turning tendency of the boring chisel by means of sliding clutches and other safety locking means. The complicated construction of such a turning device` necessarily makes the device particularly prone to jam, it increases wear and also expense.

To overcome the shortcomings the invention provides a device which effects the turning of the boring chisel completely automatically. Accordingly the invention provides a motor driven percussion and boring hammer provided with a tool turning device wherein a toothed disk which is secured to a reciprocating sleeve can be raised relative to and simultaneously turned with a toothed disk formed on a tool guiding socket.

The particular advantages and structural details of the invention will become apparent from the following speciiication with reference yto the accompanying drawings in which:

FIG. 1 illustrates a percussion drill hammer equipped with the device in accordance with the invention, and

FIG. 2 is a side view of a portion of the hammer illustrating particularly the sleeve with the guide slot.

The embodiment of the invention illustrated in theV drawings comprises a lower housing portion 1 adapted to accommodate the entire mechanism including the power supply means, a percussion piston 2 to the lower end of which is secured a reciprocating sleeve 3. Sleeve 3 is provided with a downwardly extending riding groove 4 in the wall thereof and has a toothed disk 5 at its "rcel lower end. A driving pin 6 extends through the rifling groove or slot 4 of the reciprocating sleeve 3 into a straight guide groove 7 of the housing 1 which secures the percussion piston 2 against turning.

The percussion drill has a handle 10 secured to the housing 11 of the tool and provided with a switch 12 which when operated actuates the electromotor 13. The motor 13 is journalled in bearings 14, 15 and has a toothed gear 16 which meshes with and drives a bevel gear 17. Bevel -gear 17 is secured and journalled in

bearings

18, 19. A pin 20 is secured to the bevel gear 17 to which a connecting rod 22 is secured by means of a bearing 21. The connecting rod 22 is linked by means of a pivot pin 23 to a guide piston 24.

The guide piston 24 and a guide rod 25 are operative to drive an oscillating spring system which comprises a helical spring 26 and a plurality of disk or

cup springs

27, 28, 29. The nests of springs are disposed in a percussion piston 30 which extends for reciprocating movement axially of the lower housing portion 1. Springs 26, 27 are supported `at the bottom against the bottom 2 of the percussion piston 30 by way of spring plate 31 or against the collar 32 of the guide rod 25. At the top the

spring assembly

26, 27 is biased against the

spring assembly

28, 29 or the glide piston 24. The

upper spring assembly

28, 29 is held on the one hand by the upper spring ring 33 and on the other hand by the shoulder 34 in the percussion'piston 30, respectively, the

lower spring assembly

26, 27. An intermediate ring 35 is provided between

springs

28 and 29 which serves as a guide for the guide piston 24 and as a spacing ring for the

disk springs

28, 29.

During each up or down movement of the percussion piston 2 the driver or pin 6 which extends through the rifle slot 4 and is secured against rotation in the straight guide groove 7 imparts a reciprocating rotary movement to the reciprocating sleeve 3, whereby during each upward thrust of the percussion piston 2 the axial component of force effects simultaneously the raising of the reciprocating sleeve The toothed disk 5 secured to the bottom of the reciprocating sleeve presents teeth extending in the direction of the percussion piston 2. The opposite or counter member for this is formed by a toothed disk 8 arranged within the reciprocating sleeve 3. This toothed disk 8 is formed on the tool guiding socket 9 and rotatable therewith but is not axially displaceable.

By raising the reciprocating sleeve 3 during each upward movement of the percussion piston 2, the two oppositely disposed toothed disks I5 and S come into engagement, so that with each rotation of the reciprocating sleeve 3 also a rotation of the tool guiding socket 9 is effected, the angle of rotation of which depends on the length of the rie slot `4 and on its inclination with respect to the longitudinal axis of the reciprocating sleeve 3.

During the downward movement of the percussion piston 2 the reciprocating sleeve 3 is turned back through the same angle, but simultaneously a force rbecomes eiecti-ve in a 'vertically downward direction which separates the toothed disk 5 which is connected with the reciprocating sleeve 3 from the toothed disk '8, so that the tool guiding socket y9 does not follow the return rotational'movement of the reciprocating sleeve 3.

Having now described my invention with reference to the embodiment illustrated in the drawings, I do not wish to be limited thereto, but what 'I desire to protect by Letters Patent of the United States is set forth in the appended claims.

I claim:

1. A power driven percussion hammer and drill of the type provided with a tool turning means and comprising a housing, said tool turning means comprising a reciprocating sleeve arranged in the lower end of said housing, a first toothed disk provided on the lower end of said sleeve, a tool guiding socket disposed in the lower end of said housing, a second toothed disk provided on said socket and disposed opposite said rst toothed disk and means for raising said iirst toothed disk to engage 'and turn with said secondrtoothed disk, said means comprising a percussion piston having a driver pin and said sleeve being in force transmitting relation with said piston and having a rifle slot receiving said driver pin for reciprocating movement therein for turning Vsaid sleeve and said lfirst toothed Y disk. e

2. `A power driven percussion hammer and drill of the type provided with a tool turning means and comprising a housing, said tool turning means comprising aereciproeating sleeve arranged in the lower end of said housing, a irst toothed ydisk provided onthe lower end of said sleeve, a tool guiding socket disposed inthe lower end of said housing, a second toothed disk provided ori said socket and disposed opposite said` irst toothed disk and means for raising said first toothed disk to engage and turn with said second toothed disk, said means comprising a percusdriver pin extending into said guide groove for straight line movement therein. e

References Cited by the Examiner UNITED STATES` PATENTS 1,244,386 10/1917 spehar 1731+110 2,028,252 1/1936 slaterY 173-109 2,791,909y 5/1957 Riek 74.-89 2,944,431 7/1960 Dexter 74-89 FOREIGN. PATENTS 347,355 1/1922l Germany. 688,917 12/1938.- Germany.

FRED C. MATTERN, Jg., Primary Examiner. L. P. KESSDER, Assistant Examiner.

Claims

1. A POWER DRIVEN PERCUSSION HAMMER AND DRILL OF THE TYPE PROVIDED WITH A TOOL TURNING MEANS AND COMPRISING A HOUSING, SAID TOOL TURNING MEANS COMPRISING A RECIPROCATING SLEEVE ARRANGED IN THE LOWER END OF SAID HOUSING, A FIRST TOOTHED DISK PROVIDED ON THE LOWER END OF SAID SLEEVE A TOOL GUIDING SOCKET DISPOSED IN THE LOWER END OF SAID HOUSING, A SECOND TOOTHED DISK PROVIDED ON SAID SOCKET AND DISPOSED OPPOSITE SAID FIRST TOOTHED DISK AND MEANS FOR RAISING SAID FIRST TOOTHED DISK TO ENGAGE AND TURN WITH SAID SECOND TOOTHED DISK, SAID MEANS COMPRISING A PERCUSSION PISTON HAVING A DRIVER PIN AND SAID SLEEVE BEING IN FORCE TRANSMITTING RELATION WITH SAID PISTON AND HAVING A RIFLE SLOT RECEIVING SAID DRIVER PIN FOR RECIPROCATING MOVEMENT THEREIN FOR TURNING SAID SLEEVE AND SAID FIRST TOOTHED DISK.