Elastic protective cap to be placed over a polygonal tool shank

Abstract

Protective cap to be placed over a political tool shank that consists of an at least partly ring-shaped casing, on which, in the vicinity of a base part, a terminating ring with a ring-shaped insertion-guide profile is shaped, wherein the casing and the terminating ring together form a receptacle space for the tool shank, wherein in the direction in which the protective cap is pushed onto the tool shank, the base-side annular area transitions into a cover-side trochoidal area which is adapted to the polygonal shape of the tool shank.

Claims

1. A protective cap for covering a tool shank that has a polygonal shape, said protective cap comprising: a casing that is at least partly cylindrically-shaped, said casing having a base end and an opposite end that is oppositely disposed on said casing from said base end; and a terminating ring that is connected to said casing adjacent the base end of said casing, said terminating ring defining a ring-shaped insertion-guide profile, said casing and said terminating ring cooperating to define a receptacle space for the tool shank, said casing transitioning from an annular surface at the base end to a trochoidal surface at said opposite end, said trochoidal surface corresponding to the shape of said tool shank.

2. The protective cap of claim 1 wherein said tool shank has a base with a trochoidal shape, said protective cap having a trochoidal surface with a shape that corresponds to the trochoidal shape of the tool shank.

3. The protective cap of claim 1 wherein said casing defines an inner surface that includes at least one wedge-shaped area that projects radially inwardly into said receptacle space to reduce the width between opposite sides of the receptacle space.

4. The protective cap of claim 2 wherein said tool shank defines transitional surfaces, the cover surface of said protective cap including centering lugs that project radially inwardly to define centering surfaces between said centering lugs, said centering surfaces interacting with said transitional surfaces of said tool shank.

5. The protective cap of claim 1 wherein said protective cap is press fitted on said tool shank.

6. The protective cap of claim 3 wherein the at least one wedge-shaped area includes at least two wedge shaped areas; and wherein at least one curved surface is located in the receptacle space between the wedge-shaped areas, said at least one curved surface having a radius of curvature that is greater than a radius of said wedge-shaped areas.

7. The protective cap of claim 1 wherein said tool shank includes at least one recess, said protective cap including at least one locking lug that is located adjacent said terminating ring, said locking lug engaging said at least one recess on the tool shank to form a locking connection between said protective cap and said tool shank.

8. The protective cap of claim 4, wherein wedge-shaped surfaces are regularly distributed on the inside of the periphery of said protective cap at intervals of 120 degrees, said centering lugs being located between said wedge-shaped surfaces and distributed at angular intervals of 120 degrees so that there is a peripheral angular separation of 60 degrees between said centering lugs and said wedge-shaped surfaces.

9. The protective cap of claim 3 wherein the at least one wedge-shaped area corresponds to the trochoidal shape of the tool shank.

Description

(1) The invention is explained in greater detail below on the basis of only one approach to an embodiment, which is illustrated in the accompanying drawings. Additional features and advantages that are essential to the invention are illustrated in the drawings and explained in the accompanying description,

(2) in which:

(3) FIG. 1: view in perspective of the protective cap from the base side

(4) FIG. 2: view in perspective of the protective cap from the cover side

(5) FIG. 3: the view according to FIG. 2 from the cover side

(6) FIG. 4: the side view of the protective cap

(7) FIG. 5: the bottom view of the protective cap illustrated in FIG. 1

(8) FIG. 6: an illustration identical to the one in FIG. 4 except rotated

(9) FIG. 7: a head-on view of a tool holder

(10) FIG. 8: the side view of the tool holder

(11) FIG. 9: the side view of the tool holder illustrated in FIG. 8 rotated by 90 degrees

(12) FIG. 10: an assembly drawing illustrating the placement of the protective cap on the polygonal tool shank of the tool holder

(13) FIG. 11: the further advance of the slipping on of the cap in comparison to FIG. 10

(14) FIG. 12: the full protective position of the protective cap covering the polygonal took shank

(15) FIG. 13: a schematic illustration of the basic shape of the elastic protective cap according to the invention

(16) FIG. 14: the end view of the system illustrated in FIG. 15 with the protective cap in place

(17) FIG. 15: the side view of the system with the protective cap in place

(18) FIG. 16: the side view from FIG. 15 rotated by 90 degrees

(19) FIG. 17: a view in perspective as the protective cap placed on the polygonal tool shank

(20) FIG. 18: the position illustrated in FIG. 17 rotated by 90 degrees

(21) FIG. 19: the protective cap placed completely over the polygonal tool shank

(22) The protective cap 1 illustrated in FIGS. 1 to 6 is made essentially of an elastically deformable plastic, such as a propylene or similar material, for example.

(23) The important thing is that the material of the protective cap is thin-walled to make possible a certain minor elastic expansion of the protective cap.

(24) As illustrated in the exemplary embodiment in FIGS. 1 to 6, the protective cap consists of an annular cylindrical casing 2 which, however, according to the general description, is not in the form of a ring-shaped profile, but has a special slip-on profile which will be discussed in greater detail below.

(25) On the bottom end of the cylindrical casing 2, on the base side, is a terminating ring 3 that is approximately ring-shaped and also forms a likewise ring-shaped encircling end surface 4.

(26) The cylindrical casing 2 is then formed on the terminating ring 3, wherein the shape of the cylindrical casing is generally the shape illustrated in FIG. 13. In the figure, the base side of the protective cap 1, i.e. the area around the terminating ring 3, is in the shape of a ring 17, and the transitional surfaces 19 that start at the ring 17 and are adapted in the vicinity of the cover surface 36 to the trochoidal shape of the trochoidal shank 21 which is described below.

(27) In FIG. 2, the cylindrical casing 2 is first provided on its base side with wedge-shaped areas 6 that expand upward, whereby preferably three wedge-shaped areas 6 are uniformly distributed on the periphery, wherein the wedge-shaped areas 6 project from the outside radially inward into the receptacle space 5, and therefore reduce the clear width of the receptacle space 5 at the points where the wedge-shaped areas 6 are located.

(28) Between the wedge-shaped areas 6, curved surfaces 7 are located in the receptacle space 5 that have a larger radius of curvature than the adjacent wedge-shaped areas 6.

(29) The curved surfaces 7 are used for the shape-adapted contact against the trochoidal surfaces 27 of the trochoidal shank 21, as illustrated in FIGS. 7 to 9, while the wedge-shaped areas 6 that have a larger radius of curvature are designed to be in contact with the transitional surfaces 28 that have a greater radius of curvature of the trochoidal shank 21.

(30) The cylindrical casing 2 which is adapted to the trochoidal shape, is open on top and does not have a cover.

(31) The invention is not restricted to this embodiment. A cover surface can be provided, in other words, the protective cap 1 can be closed in the vicinity of the upper annular surface 8.

(32) In the open embodiment illustrated here, one can see through the cover-side opening 16 and see the inwardly projecting centering lugs 15 located in the vicinity of the top cover side, which lugs assume a specified distance from one another and between which centering surfaces 35 are formed.

(33) On the external periphery, the cylindrical casing 2 is provided with gripping surfaces 13 that are used only to facilitate handling and otherwise have no additional function. At this point it is important that the cover surface 36 (see FIG. 13) is in the form of a trochoidal surface 9, the shape of which corresponds to the trochoidal shape 18 of the trochoidal shank 21.

(34) Therefore the cap-side trochoidal surface 9 has a shape that is adapted to allow it to rest against the shank-side trochoidal surfaces 27 and therefore optimally protects the latter surfaces against damage.

(35) It should be noted that the base-side terminating ring 3 forms a base-side annular surface 10, and the lower insertion-guide profile 11 is approximately ring-shaped, while the upper slip-on profile which is formed in the vicinity of the trochoidal surface 9 on the cover side has a trochoidal shape.

(36) The adaptation profile 12 located on the cover side is therefore adapted in terms of shape to the trochoidal shape 18 of the trochoidal shank 21.

(37) In and of itself, a press fit of this type would suffice to guarantee an automatic centering of the protective cap 1 on a trochoidal shank, as illustrated in FIGS. 7 to 9.

(38) In the figures, the tool holder 20 consists of a coupling part 22 which continues forward in the form of a trochoidal shank 21, which consists essentially of 3 trochoidal surfaces 27 with a given, reduced radius of curvature uniformly offset from one another, between which are transitional surfaces 28 with a larger, or greater radius of curvature.

(39) This trochoidal shank 21 is to be covered with a matching shape by the protective cap 1 claimed by the invention, and is to be protected by a press fit so that the protective cap 1 is automatically centered when it is slipped onto the trochoidal shank 21.

(40) This automatic centering is achieved in that, when the approximately ring-shaped insertion-guide profile 11 on the base side of the protective cap is initially placed over the trochoidal shank 21, the trochoidal surfaces 27 with the transitional surfaces 28 in between them run along the wedge-shaped areas 6 that project radially inward and in a cone shape in the axial direction, so that the wedge-shaped areas slide along the trochoidal surfaces 27 and are thus automatically, angularly centered on the trochoidal surfaces 27 of the trochoidal shank 21.

(41) To then achieve a final centering, the invention further provides that on the cover side 36 there are additional centering lugs 15 distributed uniformly around the periphery with centering surfaces 35 formed between them, which extend beyond the transitional surfaces 28 between the trochoidal surfaces 27, and thus guarantee a form-fitting centering of the protective cap 1 on the trochoidal shank 21.

(42) A press fit of this type, in and of itself, would already suffice.

(43) In one development of the invention, however, the invention teaches that on the base side, in the vicinity of the terminating ring 3, locking lugs 14 that project radially inward are provided on the inside and are engaged in at least one partial recess 26 at the base of the trochoidal shank 21, as illustrated in FIGS. 10 to 12.

(44) In this manner, there is an elastic locking of the base side of the protective cap 1 at the base of the trochoidal shank 21, so that the terminating ring 3 is in contact with the stop surface 25 on the coupling part 22.

(45) In addition, the trochoidal shank 21 has an annular space 32 that continues in the axial direction into a screw receptacle 23 with a female thread 24 located there.

(46) FIG. 10 shows that the trochoidal shank 21 is shaped in the axial direction in the form of a slightly conical surface 30, and the cylindrical casing 2 of the print tech tips cap 1 is accordingly slightly conical in the direction in which it is placed over the shank (arrow 29).

(47) The locking of the protective cap illustrated in FIG. 12 is selected so that on the inner cover surface of the protective cap 1, there is a recess 31 toward the front end surface of the trochoidal shank 21 is formed. In this manner it is always guaranteed that the protective cap 1 can be locked in a secured position on the trochoidal shank.

(48) FIGS. 14 to 19 illustrate the various motions executed by the protective cap 1 when it is placed over the trochoidal shank 21, whereby in particular during the transition from FIG. 17 to FIG. 18 it is apparent that if it is placed on in incorrect position, if, for example, the wedge-shaped areas 6 are in the vicinity of the transitional surfaces 28 that have a smaller radius of curvature, the wedge-shaped areas 6 are automatically angularly rotated away from these transitional surfaces 28 and therefore the protective cap 1 is automatically rotated into the proper position illustrated in 17.

(49) Therefore an automatic placement of the protective cap is easily possible and requires no trial-and-error checking, as with the protective caps described in the prior art.

NOMENCLATURE

(50) 1 Protective cap

(51) 2 Cylindrical casing

(52) 3 Terminating ring

(53) 4 End surface

(54) 5 Receptacle space

(55) 6 Wedge-shaped area

(56) 7 Curved surface

(57) 8 Ring-shaped surface (top)

(58) 9 Trochoidal surface

(59) 10 Ring-shaped surface (bottom)

(60) 11 Introduction profile (bottom)

(61) 12 Adaptation profile

(62) 13 Gripper surface

(63) 14 Locking lug (bottom)

(64) 15 Centering lug (top)

(65) 16 Opening

(66) 17 Ring-shape

(67) 18 Trochoidal shape

(68) 19 Transitional area

(69) 20 Tool holder

(70) 21 Trochoidal shank

(71) 22 Coupling part

(72) 23 Screw receptacle

(73) 24 Female thread

(74) 25 Stop surface

(75) 26 Recess

(76) 27 Trochoidal surface

(77) 28 Transitional area

(78) 29 Arrow

(79) 30 Conical surface

(80) 31 Recess

(81) 32 Annulus

(82) 33

(83) 34

(84) 35 Centering surface

(85) 36 Cover surface