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EP-4067579-B1 - SHIELD ARRANGEMENT AND BREAKING HAMMER

EP4067579B1EP 4067579 B1EP4067579 B1EP 4067579B1EP-4067579-B1

Inventors

  • Airas, Erik
  • HUOTARI, Juho
  • NIEMI, IIKKA
  • INTONEN, JUHA
  • LUOKKALA, Jarkko

Dates

Publication Date
20260506
Application Date
20210330

Claims (9)

  1. A shield arrangement (7) of a breaking hammer (1), wherein the shield arrangement (7) comprises: at least one shield element (11) for providing mechanical protection for a body (8) of the breaking hammer (1); at least one fastening element for mounting the shield element (11) to the body (8); the at least one fastening element being a sleeve-like element, wherein the sleeve-like element is a tool bushing (9) comprising an inner opening (27) for a breaking tool (6); the shield element (11) comprises a through opening (26) for receiving the sleeve-like element; and wherein the tool bushing (9) is provided with a thickened outer diameter at its one end which is surrounded by the shield element (11); characterized in that the shield element (11) is made of wear-resistant steel; the tool bushing (9) comprises at least one transverse locking opening (19) for receiving a transverse locking pin (10), whereby the locking pin (10) is configured to fasten the shield element (11) to the body (8) of the breaking hammer (1) via the tool bushing (9); and at the thickened end portion of the tool bushing (9) there is at least one sealing ring (20) mounted on its inner periphery.
  2. The shield arrangement as claimed in claim 1, characterized in that between the shield element (11) and the sleeve-like fastening element there are axial mating surfaces (22).
  3. The shield arrangement as claimed in claim 1 or 2, characterized in that the shield element (11) has a disc-shaped configuration.
  4. A breaking hammer (1), comprising: an elongated body (8); an impact device (4) arranged inside the body (8) and configured to generate impact pulses; characterized in that the breaking hammer (1) is provided with a shield arrangement (7) which is in accordance with claims 1 - 3, wherein the tool bushing (9) supports a breaking tool (6) to a first end (8a) of the body (8); and the shield element (11) provides mechanical protection for the body (8); and wherein the shield element (11) is fastened to the body (8) by means of the tool bushing (9).
  5. The breaking hammer as claimed in claim 4, characterized in that the shield element (11) is fastened to the body (8) only by means of the tool bushing (9).
  6. The breaking hammer as claimed in claim 4 or 5, characterized in that the fastening of the shield element (11) is without any elements generating tightening forces between the shield element (11) and the body (8).
  7. The breaking hammer as claimed in any one of the preceding claims 4-6, characterized in that the shield element (11) is arranged between a distal axial end of the body (8) and a flange (17) which is located at a distal end portion of the tool bushing (9).
  8. The breaking hammer as claimed in any one of the preceding claims 4 - 7, characterized in that the tool bushing (9) is mounted to the body (8) by means of the at least one transverse locking pin (10); and the at least one locking pin (10) is configured to fasten the shield element (11) to the body (8) via the mentioned fastening of the tool bushing (9).
  9. The breaking hammer as claimed in any one of the preceding claims 4 -8, characterized in that the shield element (11) comprises an axial mating surface transverse to the mentioned opening, whereby the axial mating surface is configured to be supported against an axial distal surface of the body (8) of the breaking hammer (1); and the mentioned axial mating surface is the only contact surface configured to be in contact with the body (8) of the breaking hammer (1).

Description

Background of the invention The invention relates to a shield arrangement for protecting a breaking hammer against mechanical wearing and deformation. The invention further relates to a breaking hammer for providing a breaking hammer with mechanical protection. The field of the invention is defined more specifically in the preamble of the independent claim. Breaking hammers are used to break hard materials, such as rock, concrete, and the like. The breaking hammer comprises a percussion device for generating impact pulses to a breaking tool connectable to the breaking hammer. The breaking hammers are used in demanding conditions and their structure is subjected to different damaging phenomena. Therefore, the breaking hammer may be provided with a shield element which may cover a body of the breaking hammer and may thereby provide protection against dents and wearing. Such a breaking hammer, according to the preamble of claim 1, is known from US 2017/282345 A1. However, the known solutions have shown including drawbacks relating their complicated structure and mounting. Brief description of the invention An object of the invention is to provide a novel and improved shield arrangement and breaking hammer, and further to provide a novel and improved method of providing a breaking hammer with mechanical protection. The shield arrangement according to the invention is characterized by the characterizing features of independent claim 1. The breaking hammer according to the invention is characterized by the features of dependent claim 4. An idea of the disclosed solution is that a breaking hammer is provided with a shield arrangement. The shield arrangement comprises one or more shield elements for providing mechanical protection for a body of the breaking hammer. The arrangement further comprises a separate sleeve-like element configured to serve as a fastening element for mounting the shield element to the body. Then the shield element comprises a through opening for receiving the sleeve-like element. An advantage of the disclosed solution is that the structure of the shield arrangement and its mounting may be relatively simple. According to an embodiment, the shield element is a removable and changeable wear part. Then the shield element can be easily replaced or repaired. According to an embodiment, the shield element is configured to provide the mechanical protection only for a tool side end part of the body of the percussion hammer. In other words, the shield element is a low shield providing protection only for a lower end part of the body which may be subjected to intensive wearing during the rock breaking operation. An advantage is that the shield element does not increase weight of the breaking hammer unnecessarily and does not form visual obstruction. According to an embodiment, fastening of the shield element is based on shape locking principle and the shield element is without any fastening screws, fastening screw holes, pins or corresponding elements intended for the fastening. An advantage is that the structure may be more tolerant against external forces and wearing when the structure is free of vulnerable fastening elements. Also dismounting and mounting at a work site may be facilitated. According to an embodiment, the disclosed arrangement implements tool-free mounting principle. Thereby the shield arrangement can be replaced easily and quickly at a work site. According to the invention, the sleeve-like element of the shield arrangement is a tool bushing comprising an inner opening for a breaking tool. In other words, the tool bushing is a dual purpose element serving as the fastening element for the shielding element, and it also serves as a support element for supporting and bearing the breaking tool. The shield element is supported on the outer surface of the tool bushing and the breaking tool is supported on the inner surface of the tool bushing. According to an embodiment, the tool bushing is provided with slide bearing surfaces on its inner surfaces. According to the invention, the tool bushing is provided with a thickened outer diameter at its one end which is surrounded by the shield element. Further, at the thickened end portion there is at least one sealing ring mounted on its inner periphery. According to the invention, the tool bushing comprises at least one transverse locking opening for receiving a transverse locking pin. The locking pin is configured to fasten the shield element to the body of the percussion hammer via the tool bushing. According to an embodiment, the shield element is fastened to the body only by means of the transverse locking pin. According to an embodiment, between the shield element and the sleeve-like fastening element there are axial mating surfaces. According to an embodiment, the axial mating surfaces are slanted i.e. they are angled relative to longitudinal axis of the sleeve-like fastening element. An advantage of the slanted mating surfaces is that the